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- 1. J. Appl. Phys. 102, 103514 (2007) , AIP , “Characterization of defects in ZnO nanocrystals: Photoluminescence and positron annihilation spectroscopic studies”, A. K. Mishra, S. K. Chaudhuri, S. Mukherjee, A. Priyam, A. Saha, and D. DasDefects present in ZnO nanocrystals prepared by a wet chemical method have been characterized by photoluminescence (PL) and positron annihilation spectroscopy (PAS) techniques. The as-prepared sample was heat treated at different temperatures to obtain nanocrystals in the size range of 19–39 ... (Read more)
- 2. J. Appl. Phys. 101, 024324 (2007) , “Electron paramagnetic resonance in transition metal-doped ZnO nanowires”, A. O. Ankiewicz, M. C. Carmo, N. A. Sobolev, W. Gehlhoff, E. M. Kaidashev, A. Rahm, M. Lorenz, and M. GrundmannThe wide-band-gap zinc oxide-based diluted magnetic semiconductors currently attract considerable attention due to their possible use in spintronic devices. In this work, we studied ZnO nanowire samples synthesized on 10×10 mm2 a-plane sapphire substrates by high-pressure... (Read more)
- 3. J. Appl. Phys. 101, 013902 (2007) , “An electron paramagnetic resonance study of n-type Zn1−xMnxO: A diluted magnetic semiconductor”, A. Ben Mahmoud, H. J. von Bardeleben, J. L. Cantin, E. Chikoidze, and A. MaugerWe present the results of an electron paramagnetic resonance study of homogeneous single phase Zn1−xMnxO thin films with Mn concentrations varying between x=0.07 and x=0.34. Our results show antiferromagnetic (AF) coupling in the entire... (Read more)
- 4. Phys. Rev. B 75, 195215 (2007) , “Effect of Co and O defects on the magnetism in Co-doped ZnO: Experiment and theory”, G. S. Chang, E. Z. Kurmaev, D. W. Boukhvalov, L. D. Finkelstein, S. Colis, T. M. Pedersen, A. Moewes, and A. DiniaThe electronic structure of Zn1−xCoxO (x=0.02, 0.06, and 0.10) diluted magnetic semiconductors is investigated using soft x-ray emission spectroscopy and first-principles calculations. X-ray absorption and emission measurements reveal that most Co... (Read more)
- 5. Phys. Rev. B 75, 144404 (2007) , “Ferromagnetism in Fe-doped ZnO nanocrystals: Experiment and theory”, Debjani Karmakar, S. K. Mandal, R. M. Kadam, P. L. Paulose, A. K. Rajarajan, T. K. Nath, A. K. Das, I. Dasgupta, and G. P. DasFe-doped ZnO nanocrystals are successfully synthesized and structurally characterized by using x-ray diffraction and transmission electron microscopy. Magnetization measurements on the same system reveal a ferromagnetic to paramagnetic transition temperature above 450 K with a low-temperature... (Read more)
- 6. Phys. Rev. B 75, 085204 (2007) , “Internal structure of the neutral donor-bound exciton complex in cubic zinc-blende and wurtzite semiconductors”, Bernard Gil, Pierre Bigenwald, Mathieu Leroux, Plamen P. Paskov, and Bo MonemarWe calculate the fine structure splitting of the near band edge donor-bound excitons in major cubic semiconductors using an approach inspired by an earlier one that consists in replacing the Morse potential by a Kratzer one, in order to account for the repulsion between the donor and the hole. A... (Read more)
- 7. Phys. Rev. Lett. 98, 186804 (2007) , “Room-Temperature Electron Spin Dynamics in Free-Standing ZnO Quantum Dots”, William K. Liu, Kelly M. Whitaker, Alyssa L. Smith, Kevin R. Kittilstved, Bruce H. Robinson, and Daniel R. GamelinConduction band electrons in colloidal ZnO quantum dots have been prepared photochemically and examined by electron paramagnetic resonance spectroscopy. Nanocrystals of 4.6 nm diameter containing single S-shell conduction band electrons have g*=1.962 and a room-temperature... (Read more)
- 8. Phys. Rev. Lett. 98, 135506 (2007) , “Possible Approach to Overcome the Doping Asymmetry in Wideband Gap Semiconductors”, Yanfa Yan, Jingbo Li, Su-Huai Wei, and M. M. Al-JassimThe asymmetry doping problem has severely hindered the potential applications of many wideband gap (WBG) materials. Here, we propose a possible approach to overcome this long-standing doping asymmetry problem for WBG semiconductors. Our approach is based on the reduction of the ionization energies... (Read more)
- 9. Phys. Rev. Lett. 98, 045501 (2007) , “Dopability, Intrinsic Conductivity, and Nonstoichiometry of Transparent Conducting Oxides”, Stephan Lany and Alex ZungerExisting defect models for In2O3 and ZnO are inconclusive about the origin of conductivity, nonstoichiometry, and coloration. We apply systematic corrections to first-principles calculated formation energies ΔH, and validate our theoretical defect model against... (Read more)
- 10. Appl. Phys. Lett. 89, 262112 (2006) , “Identification of oxygen and zinc vacancy optical signals in ZnO”, T. Moe Børseth, B. G. Svensson, A. Yu. Kuznetsov, P. Klason, Q. X. Zhao, and M. WillanderPhotoluminescence spectroscopy has been used to study single crystalline ZnO samples systematically annealed in inert, Zn-rich and O-rich atmospheres. A striking correlation is observed between the choice of annealing ambient and the position of the deep band emission (DBE) often detected in ZnO. In... (Read more)
- 11. Appl. Phys. Lett. 89, 252115 (2006) , “Doping and defects in the formation of single-crystal ZnO nanodisks”, Junjie Qi, Yue Zhang, Yunhua Huang, Qingliang Liao, and Juan LiuHigh purity growth of polar surface dominated ZnO nanodisks was fabricated by introducing In ions in the raw material by thermal evaporation process without a catalyst. The nature of the sharp-contrast lines in the disks was investigated. The results suggested that the existence of sharp-contrast... (Read more)
- 12. Appl. Phys. Lett. 89, 112113 (2006) , “Control of p- and n-type conductivities in Li-doped ZnO thin films”, J. G. Lu, Y. Z. Zhang, Z. Z. Ye, Y. J. Zeng, H. P. He, L. P. Zhu, J. Y. Huang, L. Wang, J. Yuan, B. H. Zhao, and X. H. LiLi-doped ZnO films were prepared by pulsed laser deposition. The carrier type could be controlled by adjusting the growth conditions. In an ionized oxygen atmosphere, p-type ZnO was achieved, with the hole concentration of 6.04×1017 cm3 at an optimal Li... (Read more)
- 13. Appl. Phys. Lett. 89, 092122 (2006) , “Deep acceptor states in ZnO single crystals”, H. von Wenckstern, R. Pickenhain, H. Schmidt, M. Brandt, G. Biehne, M. Lorenz, M. Grundmann, and G. BrauerThe authors report the observation of both acceptor- and donorlike defects in ZnO by deep level transient spectroscopy. The observation is facilitated by using a p-n junction allowing the injection of holes and electrons. The junction is realized by implanting a n-conducting ZnO... (Read more)
- 14. Appl. Phys. Lett. 89, 082102 (2006) , “Observation of enhanced defect emission and excitonic quenching from spherically indented ZnO”, V. A. Coleman, J. E. Bradby, C. Jagadish, and M. R. PhillipsThe influence of spherical nanoindentation on the band edge and deep level emission of single crystal c-axis ZnO has been studied by cathodoluminescence (CL) spectroscopy and monochromatic imaging. Excitonic emission is quenched at the indent site and defect emission in the range of... (Read more)
- 15. Appl. Phys. Lett. 89, 042106 (2006) , “Identification of acceptor states in Li-doped p-type ZnO thin films”, Y. J. Zeng, Z. Z. Ye, J. G. Lu, W. Z. Xu, L. P. Zhu, B. H. Zhao, and Sukit LimpijumnongWe investigate photoluminescence from reproducible Li-doped p-type ZnO thin films prepared by dc reactive magnetron sputtering. The LiZn acceptor state, with an energy level located at 150 meV above the valence band maximum, is identified from free-to-neutral-acceptor transitions.... (Read more)
- 16. Appl. Phys. Lett. 89, 031902 (2006) , “Anti-Stokes photoluminescence in ZnO microcrystal”, Weitao Cao, Weimin Du, Fuhai Su, and Guohua LiLow temperature (10 K) strong anti-Stokes photoluminescence (ASPL) of ZnO microcrystal excited by low power cw 532 nm laser is reported here. Energy upconversion of 1.1 eV is obtained in our experiment with no conventional nonlinear effect. Through the study of the normal photoluminescence and... (Read more)
- 17. Appl. Phys. Lett. 89, 012508 (2006) , “Ferromagnetism in Fe-implanted a-plane ZnO films”, P. Wu, G. Saraf, Y. Lu, D. H. Hill, R. Gateau, L. Wielunski, R. A. Bartynski, D. A. Arena, J. Dvorak, A. Moodenbaugh, T. Siegrist, J. A. Raley, and Yung Kee YeoFe ions of dose 5×1016 cm2 were implanted at 200 keV into a-plane ZnO epitaxial films. The epitaxial quality of the postannealed samples was verified by x-ray diffraction -rocking curves and scans, whereas x-ray absorption spectroscopy identified the... (Read more)
- 18. Appl. Phys. Lett. 88, 242508 (2006) , “Thermal limits on field alignment of nanoparticle FePt media”, J. A. Bain, W. F. Egelhoff, Jr.We derive a simple expression for the average angular orientation distribution of ferromagnetic FePt particles in an applied field in thermal equilibrium. This system is closely related to the Langevin expression for paramagnetic susceptibility, which computes the average orientation of particles in... (Read more)
- 19. Appl. Phys. Lett. 88, 201918 (2006) , “Diffusion of zinc vacancies and interstitials in zinc oxide”, Paul Erhart and Karsten AlbeThe self-diffusion coefficient of zinc in ZnO is derived as a function of the chemical potential and Fermi level from first-principles calculations. Density functional calculations in combination with the climbing image-nudged elastic band method are used in order to determine migration barriers for... (Read more)
- 20. Appl. Phys. Lett. 88, 152116 (2006) , “Donor and acceptor competitions in phosphorus-doped ZnO”, F. X. Xiu, Z. Yang, L. J. Mandalapu, and J. L. LiuPhosphorus-doped ZnO films were grown by molecular-beam epitaxy with a GaP effusion cell as dopant source. Three growth regions were identified to obtain ZnO films with different conduction types. In the oxygen-extremely-rich region, phosphorus-doped ZnO films show n-type conduction with... (Read more)
- 21. Appl. Phys. Lett. 88, 141919 (2006) , “Observation of donor-acceptor pair spectra in the photoluminescence of H- and Zn-implanted ZnO single crystals”, D. C. Reynolds, C. W. Litton, T. C. Collins, J. E. Hoelscher, J. NauseDonor-acceptor (D-A) pair spectra have been observed in the photoluminescence radiative recombination of selected donor bound exciton complexes in zinc oxide (ZnO) single crystals that have been ion implantation doped with H and Zn atoms and subsequently annealed in a nitrogen (N2)... (Read more)
- 22. J. Appl. Phys. 99, 123515 (2006) , “Raman spectroscopy of (Mn, Co)-codoped ZnO films”, C. L. Du, Z. B. Gu, M. H. Lu, J. Wang, S. T. Zhang, J. Zhao, G. X. Cheng, H. Heng, and Y. F. ChenRaman spectra of (Mn, Co)-codoped ZnO films were investigated as functions of laser line and temperature. It is shown that the Raman shifts for different phonon modes exhibit redshift with temperature increasing, which can be attributed to the anharmonic effect in the material. Strong resonant Raman... (Read more)
- 23. J. Appl. Phys. 99, 103905 (2006) , “Effect of Mn+ ion implantation on the Raman spectra of ZnO”, Hongmei Zhong, Jinbing Wang, Xiaoshuang Chen, Zhifeng Li, Wenlan Xu, and Wei LuRaman measurements have been performed on ZnO bulk materials implanted with 220 keV Mn+ ions with various doses from 1015 to 1017 cm2. The results reveal two modes at about 230 and 523 cm1, respectively, which are not observed in... (Read more)
- 24. J. Appl. Phys. 99, 093507 (2006) , “Annealing process of ion-implantation-induced defects in ZnO: Chemical effect of the ion species”, Z. Q. Chen, M. Maekawa, A. Kawasuso, S. Sakai, and H. NaramotoZnO single crystals implanted with O+ and B+ ions were studied by positron annihilation and Raman scattering measurements. Positron annihilation results show that vacancy clusters are generated by implantation. For the B+-implanted sample, the vacancy clusters have a... (Read more)
- 25. J. Appl. Phys. 99, 093505 (2006) , “Improvements in quantum efficiency of excitonic emissions in ZnO epilayers by the elimination of point defects”, S. F. Chichibu, T. Onuma, M. Kubota, A. Uedono, T. Sota, A. Tsukazaki, A. Ohtomo, and M. KawasakiThe internal quantum efficiency (int) of the near-band-edge (NBE) excitonic photoluminescence (PL) in ZnO epilayers was significantly improved by eliminating point defects, as well as by the use of ZnO high-temperature-annealed self-buffer layer (HITAB) on a ScAlMgO4 substrate... (Read more)
- 26. J. Appl. Phys. 99, 066102 (2006) , “Photoluminescence of wurtzite ZnO under hydrostatic pressure”, S. J. Chen, Y. C. Liu, C. L. Shao, C. S. Xu, Y. X. Liu, L. Wang, B. B. Liu, and G. T. ZouPhotoluminescence (PL) spectra of single-crystal ZnO bulk under hydrostatic pressure are studied using the diamond-anvil-cell technique at room temperature. The PL spectrum of ZnO single crystal taken at atmospheric pressure was dominated by a strong near-band-edge exciton emission. The emission... (Read more)
- 27. J. Appl. Phys. 99, 063709 (2006) , “Intrinsic exciton transitions in high-quality ZnO thin films grown by plasma-enhanced molecular-beam epitaxy on sapphire substrates”, X. Q. Zhang, Z. G. Yao, S. H. Huang, Ikuo Suemune, and H. KumanoHigh-quality ZnO thin films have been grown by plasma-enhanced molecular-beam epitaxy on sapphire substrates. Free-exciton absorption and exciton-LO phonon absorption peaks are observed in the films at room temperature, indicating that the exciton states are stable even at room temperature. Three... (Read more)
- 28. J. Appl. Phys. 99, 053516 (2006) , “Correlation between Zn vacancies and photoluminescence emission in ZnO films”, A. Zubiaga, J. A. García, F. Plazaola, F. Tuomisto, K. Saarinen, J. Zuñiga Pérez, and V. Muñoz-SanjoséPhotoluminescence and positron annihilation spectroscopy have been used to characterize and identify vacancy-type defects produced in ZnO films grown on sapphire by metal-organic chemical-vapor deposition. The photoluminescence of the samples in the near band edge region has been studied, paying... (Read more)
- 29. J. Appl. Phys. 99, 013502 (2006) , “Luminescence of bound excitons in epitaxial ZnO thin films grown by plasma-assisted molecular beam epitaxy”, Y. S. Jung, W. K. Choi, O. V. Kononenko, and G. N. PaninLuminescence properties of ZnO films, which have been epitaxially grown on c-sapphire (0001) substrates by plasma-assisted molecular beam epitaxy, are investigated by means of different excitation sources and their measurement conditions. With the increase of measurement temperature,... (Read more)
- 30. J. Phys. Chem. Solids 67, 789 (2006) , “Spectroscopic and magnetic studies of manganese ions in ZnO–Sb2O3–B2O3 glass system”, M. Srinivasa Reddy, G. Murali Krishna , N. VeeraiahZnO–Sb2O3–B2O3 glasses containing different concentrations of MnO ranging from 0 to 1.0 mol% were prepared. A number of studies, viz. optical absorption, infrared and ESR spectra and magnetic susceptibility, were carried out as a function of manganese ion concentration. The analysis of... (Read more)
- 31. Phys. Rev. B 74, 235208 (2006) , “Theoretical study of the magnetism of Mn-doped ZnO with and without defects”, D. Iuan, B. Sanyal, and O. ErikssonWe calculate the exchange interaction parameters of a classical Heisenberg Hamiltonian for Mn-doped ZnO (Mn concentration between 5% and 20%) by an ab initio Korringa-Kohn-Rostoker coherent-potential-approximation method in the framework of density functional theory. A weak antiferromagnetic... (Read more)
- 32. Phys. Rev. B 74, 165203 (2006) , “Isotopic-mass dependence of the A, B, and C excitonic band gaps in ZnO at low temperatures”, S. Tsoi, X. Lu, A. K. Ramdas, H. Alawadhi, M. Grimsditch, M. Cardona, and R. LauckLow temperature wavelength-modulated reflectivity measurements of isotopically engineered ZnO samples have yielded the dependence of their A, B, and C excitonic band gaps on the isotopic masses of Zn and O. The observed dependence is analyzed in terms of the band gap renormalization by zero-point... (Read more)
- 33. Phys. Rev. B 74, 161202 (2006) , “Deactivation of Li by vacancy clusters in ion-implanted and flash-annealed ZnO”, T. Moe Børseth, F. Tuomisto, J. S. Christensen, W. Skorupa, E. V. Monakhov, B. G. Svensson, and A. Yu. KuznetsovLi is present in hydrothermally grown ZnO at high concentrations and is known to compensate both n- and p-type doping due to its amphoteric nature. However, Li can be manipulated by annealing and ion implantation in ZnO. Fast, 20 ms flash anneals in the 9001400 °C range... (Read more)
- 34. Phys. Rev. B 74, 155201 (2006) , “Crystal-field theory of Co2+ in doped ZnO”, R. O. Kuzian, A. M. Daré, P. Sati, and R. HaynWe present a crystal-field theory of transition-metal impurities in semiconductors in a trigonally distorted tetrahedral coordination. We develop a perturbative scheme to treat covalency effects within the weak ligand field case (Coulomb interaction dominates over one-particle splitting) and apply... (Read more)
- 35. Phys. Rev. B 74, 144432 (2006) , “Role of defects in ferromagnetism in Zn1−xCoxO: A hybrid density-functional study”, C. H. PattersonExperimental studies of Zn1−xCoxO as thin films or nanocrystals have found ferromagnetism and Curie temperatures above room temperature and that p- or n-type doping of Zn1−xCoxO can change its magnetic... (Read more)
- 36. Phys. Rev. B 74, 115203 (2006) , “From ferromagnetic to antiferromagnetic interactions in n-type Zn1–xMnxO: An electron paramagnetic resonance study”, A. Ben Mahmoud, H. J. von Bardeleben, J. L. Cantin, A. Mauger, E. Chikoidze, and Y. DumontContradictory results concerning the formation of a ferromagnetic state in Mn doped ZnO layers have been reported in the last years. We present the results of an electron paramagnetic resonance study on homogeneous single phase n-type conductive Zn1xMnxO... (Read more)
- 37. Phys. Rev. B 74, 081201 (2006) , “Design of shallow acceptors in ZnO: First-principles band-structure calculations”, Jingbo Li, Su-Huai Wei, Shu-Shen Li, and Jian-Bai Xiap-type doping is a great challenge for the full utilization of ZnO as short-wavelength optoelectronic material. Due to a large electronegative characteristic of oxygen, the ionization energy of acceptors in ZnO is usually too high. By analyzing the defect wave-function character, we propose... (Read more)
- 38. Phys. Rev. B 74, 045208 (2006) , “Defects in virgin and N+-implanted ZnO single crystals studied by positron annihilation, Hall effect, and deep-level transient spectroscopy”, G. Brauer, W. Anwand, W. Skorupa, J. Kuriplach, O. Melikhova, C. Moisson, H. von Wenckstern, H. Schmidt, M. Lorenz, and M. GrundmannHigh-quality single crystals of ZnO in the as-grown and N+ ion-implanted states have been investigated using a combination of three experimental techniquesnamely, positron lifetime/slow positron implantation spectroscopy accompanied by theoretical calculations of the positron... (Read more)
- 39. Phys. Rev. B 74, 045204 (2006) , “Donor-acceptor pairs in the confined structure of ZnO nanocrystals”, Serguei B. Orlinskii, Hubert Blok, and Jan SchmidtThe electron paramagnetic resonance signal of an exchange-coupled pair consisting of a shallow interstitial Li donor and a deep Na-related acceptor has been identified in ZnO nanocrystals with radii smaller than 1.5 nm. From electron nuclear double resonance experiments it is concluded that the... (Read more)
- 40. Phys. Rev. B 74, 045202 (2006) , “Effects of cation d states on the structural and electronic properties of III-nitride and II-oxide wide-band-gap semiconductors”, Anderson Janotti, David Segev, and Chris G. Van de WalleUsing first-principles methods based on density functional theory within the local density approximation (LDA) we calculate the structural and electronic properties of wurtzite MgO, ZnO, and CdO, and discuss their similarities and dissimilarities with the corresponding Group-III nitrides AlN, GaN,... (Read more)
- 41. Phys. Rev. B 73, 235209 (2006) , “Temperature dependence of the vibrational spectrum of a Li-OH complex in ZnO: Infrared absorption experiments and theory”, Kevin R. Martin, Philip Blaney, Gang Shi, Michael Stavola, and W. Beall FowlerConsiderable interest has developed in the potential use of IIVI oxides as electronic and optical materials. In several cases, alkali atoms have been suggested as dopants. We report on the theoretical and experimental investigation of infrared and vibrational properties of a Li-OH complex in... (Read more)
- 42. Phys. Rev. B 73, 205203 (2006) , “First-principles study of intrinsic point defects in ZnO: Role of band structure, volume relaxation, and finite-size effects”, Paul Erhart, Karsten Albe, and Andreas KleinDensity-functional theory (DFT) calculations of intrinsic point defect properties in zinc oxide were performed in order to remedy the influence of finite-size effects and the improper description of the band structure. The generalized gradient approximation (GGA) with empirical self-interaction... (Read more)
- 43. Phys. Rev. B 73, 195204 (2006) , “Hydrogen migration in single crystal and polycrystalline zinc oxide”, N. H. NickelHydrogen diffusion in single crystal and polycrystalline zinc oxide was investigated by deuterium diffusion and hydrogen effusion experiments. Deuterium concentration depth profiles were measured as a function of the passivation temperature, while in H effusion experiments the molecular hydrogen... (Read more)
- 44. Phys. Rev. B 73, 115207 (2006) , “First-principles study of migration mechanisms and diffusion of oxygen in zinc oxide”, Paul Erhart and Karsten AlbeWe have performed density-functional theory calculations in conjunction with the climbing image nudged elastic band method in order to study the self-diffusion of oxygen in zinc oxide. To this end, we have derived the complete set of migration paths for vacancies as well as interstitials in wurtzite... (Read more)
- 45. Phys. Rev. Lett. 97, 106802 (2006) , “Role of Pr Segregation in Acceptor-State Formation at ZnO Grain Boundaries”, Yukio Sato, James P. Buban, Teruyasu Mizoguchi, Naoya Shibata, Masatada Yodogawa, Takahisa Yamamoto, and Yuichi IkuharaThe role of Pr doping on double Schottky barrier formations at ZnO single grain boundaries was investigated by the combination of current-voltage measurements, atomic-resolution Z-contrast scanning transmission electron microscopy, and first-principles calculations. Although Pr segregated to... (Read more)
- 46. Phys. Rev. Lett. 96, 17203 (2006) , “Magnetic Anisotropy of Co2+ as Signature of Intrinsic Ferromagnetism in ZnO:Co”, P. Sati, R. Hayn, R. Kuzian, S. Régnier, S. Schäfer, A. Stepanov, C. Morhain, C. Deparis, M. Laügt, M. Goiran, and Z. GolackiWe report on the magnetic properties of thoroughly characterized Zn1-xCoxO epitaxial thin films, with low Co concentration, x=0.0030.005. Magnetic and EPR measurements, combined with crystal field theory, reveal that isolated Co2+ ions in... (Read more)
- 47. Superlatt. Microstruct. 39, 247-256 (2006) , “Optical and morphological features of bulk and homoepitaxial ZnO”, R. Yakimova, G.R. Yazdi, N.T. Son, I. Ivanov, M. Syväjärvi, S. Sun, G. Tompa, A. Kuznetsov , B. SvenssonZnO substrate crystals from two different sources, and epitaxial layers have been studied by SEM, AFM, photoluminescence and EPR. Although fabricated by the same growth principle, i.e. the hydrothermal technique, the substrates differ in terms of purity and structural quality. In the PL spectra of... (Read more)
- 48. Thin Solid Films 496, 169-173 (2006) , “Green luminescence from Mn ions in ZnO–GeO2 glasses prepared by sol–gel method and their glass ceramics”, Tomoe Sanada, Kazuhiro Yamamoto, Noriyuki Wada , Kazuo KojimaZn2SiO4:Mn2+ is one of the green light luminants used for cathode ray tubes of televisions. Recently, optical materials emitting strong visible light under lower energy excitation have been expected. To obtain new luminants of high quality, we prepared Mn ion doped ZnO–GeO2 glasses and glass... (Read more)
- 49. Appl. Phys. Lett. 87, 223111 (2005) , “Time-resolved photoluminescence from ZnO nanostructures”, W. M. Kwok, A. B. Djuriši?, Y. H. Leung, W. K. Chan, D. L. PhillipsDifferent ZnO nanostructures (tetrapods, shells, rods, and highly faceted rods) were characterized by photoluminescence (PL) and time-resolved PL measurements. It was found that different nanostructures exhibit very different optical properties in terms of defect emission and decay times of the... (Read more)
- 50. Appl. Phys. Lett. 87, 211912 (2005) , “Deep-level emissions influenced by O and Zn implantations in ZnO”, Q. X. Zhao, P. Klason, M. Willander, H. M. Zhong, W. Lu, J. H. YangA set of bulk ZnO samples implanted with O and Zn at various densities were investigated by photoluminescence. The implantation concentration of O and Zn is varied between 1×1017/cm3 and 5×1019/cm3. The samples were thermally treated in an... (Read more)
- 51. Appl. Phys. Lett. 87, 172108 (2005) , “Production of native donors in ZnO by annealing at high temperature in Zn vapor”, L. E. Halliburton, N. C. Giles, N. Y. Garces, Ming Luo, Chunchuan Xu, Lihai Bai, L. A. BoatnerZinc oxide crystals grown by the seeded chemical vapor transport method have been annealed in zinc vapor at 1100 °C for 30 min. These thermochemical reduction treatments produce a deep red coloration in the crystals and increase their n-type electrical conductivity. Electron paramagnetic... (Read more)
- 52. Chem. Phys. Lett. 415, 337 (2005) , “No ferromagnetism in Mn doped ZnO semiconductors”, J. Alaria, P. Turek, M. Bernard, M. Bouloudenine, A. Berbadj, N. Brihi, G. Schmerber, S. Colis , A. DiniaPolycrystalline Zn1 − xMnxO was synthesized by co-precipitation method with xvarying between 0.01 and 0.10. Although X-ray diffraction patterns show a typical würtzite structure with no additional peaks for all samples, Raman spectroscopy indicates the appearance of an additional mode in... (Read more)
- 53. J. Magn. Magn. Mater. 302, 118 (2005) , “Magnetism origin of Mn-doped ZnO nanoclusters”, J.H. Li, D.Z. Shen, J.Y. Zhang, D.X. Zhao, B.S. Li, Y.M. Lu, Y.C. Liu , X.W. FanZnMnO nanoclusters were synthesized by the sol–gel method. The structural and magnetic characters were investigated. The XRD spectrum shows ZnMnO nanoclusters are hexagonal wurtzite structures and a small quantity of ZnMn2O4 phase is also present in the spectrum. The percentages of Zn and Mn... (Read more)
- 54. J. Quant. Spectrosc. Radiat. Transfer 90, 97-113 (2005) , “Spectroscopic investigations on ZnF2–MO–TeO2 (MO=ZnO, CdO and PbO) glasses doped with chromium ions”, C. Laxmi Kanth, B. V. Raghavaiah, B. Appa Rao , N. VeeraiahDifferential scanning calorimetric studies, spectroscopic studies (viz., optical absorption, ESR, infrared spectra) and thermoluminescence studies of ZnF2–MO–TeO2 (MO=ZnO, CdO and PbO) glasses doped with different concentrations of chromium ions have been investigated. Results have... (Read more)
- 55. Mater. Sci. Eng. C 25, 614-617 (2005) , “Incorporation of cobalt into ZnO nanoclusters”, Igor Ozerov, Françoise Chabre and Wladimir MarineThe structural, optical and magnetic properties of nanostructured ZnO films co-doped with cobalt and aluminium have been studied. The nanocrystalline films, with cluster sizes in range 50–100 nm, were deposited by pulsed laser ablation in a mixed atmosphere of oxygen and helium. The... (Read more)
- 56. Phys. Rev. B 71, 115205 (2005) , “Origin of the 6885-cm–1 luminescence lines in ZnO: Vanadium versus copper”, L. S. Vlasenko, G. D. Watkins, R. HelbigOptical detection of electron paramagnetic resonance reveals the I=7/2 EPR spectrum of V2+ in the sharp photoluminescence (PL) lines often observed at ~6885 cm1 in ZnO, which have universally been assumed previously to arise from copper. An alternative model for... (Read more)
- 57. Spectrochim. Acta A. 61, 2595-2602 (2005) , “VO2+ ions in zinc lead borate glasses studied by EPR and optical absorption techniques”, P. Giri Prakash , J. Lakshmana RaoElectron paramagnetic resonance (EPR) and optical absorption spectra of vanadyl ions in zinc lead borate (ZnO–PbO–B2O3) glass system have been studied. EPR spectra of all the glass samples exhibit resonance signals characteristic of VO2+ ions. The values of spin-Hamiltonian parameters... (Read more)
- 58. Superlatt. Microstruct. 38, 413-420 (2005) , “EPR study on magnetic Zn1−xMnxO”, Mariana Diaconu, Heidemarie Schmidt, Andreas Pöppl, Rolf Böttcher, Joachim Hoentsch, Andreas Rahm, Holger Hochmuth, Michael Lorenz ,Marius GrundmannDiluted magnetic semiconductors (DMS), systems formed by replacing cations of the host semiconductor material with transition-metal ions, are developed for further use in spintronics. A good combination as a DMS is Zn1−xMnxO due to the ZnO wide band gap (3.37 eV) and the matching ionic... (Read more)
- 59. Appl. Phys. Lett. 85, 1601 (2004) , “Different origins of visible luminescence in ZnO nanostructures fabricated by the chemical and evaporation methods”, D. Li, Y. H. Leung, A. B. Djurisic, Z. T. Liu, M. H. Xie, S. L. Shi, S. J. Xu, W. K. ChanWe prepared ZnO nanostructures using chemical and thermal evaporation methods. The properties of the fabricated nanostructures were studied using scanning electron microscopy, x-ray diffraction, photoluminescence, and electron paramagnetic resonance (EPR) spectroscopy. It was found that the... (Read more)
- 60. Appl. Phys. Lett. 84, 2635 (2004) , “Visible photoluminescence in ZnO tetrapod and multipod structures”, Aleksandra B. Djurisic, Yu Hang Leung, Wallace C. H. Choy, Kok Wai Cheah, Wai Kin ChanThe properties of ZnO tetrapod and multipod structures were investigated using scanning electron microscopy, x-ray diffraction, photoluminescence (PL), and electron paramagnetic resonance (EPR) spectroscopy. While there is relationship between g = 1.96 EPR and green PL in some of the samples,... (Read more)
- 61. Mater. Sci. Eng. A 375-377, 620-624 (2004) , “Evolution of the microstructure of disperse ZnO powders obtained by the freeze-drying method”, Z. V. Marinkovic, O. Milosevic, M. V. Nikolic, M. G. Kakazey, M. V. Karpec, T. V. Tomila , M. M. RisticFreeze-drying, as a cryochemical powder processing method is applied in the synthesis of ZnO submicrometer to nanosized powders. The process involves rapid freezing of the sprayed precursor solution, drying under vacuum by sublimation of the solvent and salt decomposition to oxide by thermal... (Read more)
- 62. Phys. Rev. Lett. 92, 47602 (2004) , “Overhauser Effect of 67Zn Nuclear Spins in ZnO via Cross Relaxation Induced by the Zero-Point Fluctuations of the Phonon Field”, Hubert Blok, Serguei B. Orlinski, Jan Schmidt, Pavel G. BaranovHole burning in and displacements of the magnetic-resonance absorption line of the electron spin of the shallow hydrogen-related donor in ZnO are observed upon resonant irradiation with microwaves at 275 GHz and at 4.5 K in a magnetic field of 10 T. These effects arise from an almost complete... (Read more)
- 63. Semiconductors 38, 31-35 (2004) , “Green Luminescence Band of Zinc Oxide Films Copper-Doped by Thermal Diffusion”, Ya. I. Alivov, M. V. Chukichev, V. A. NikitenkoHigh quality ZnO single-crystal films were doped with copper by thermal diffusion, and their luminescent properties were studied by cathodoluminescence spectroscopy. Doping with copper increases the intensity of the green-emission band of the cathodoluminescence spectrum, whose peak, width, and shape at 78 and 300 K remain unchanged. At 4.2 K, a pronounced phonon structure with a phonon energy of 72 meV is detected in the cathodoluminescence green-emission band of the doped samples. In this case, the phonon peaks feature a triplet fine structure instead of the doublet one generally observed. This feature is attributed to radiative recombination of acceptor excitons that are localized at copper atoms and interact with each one of the subbands of the ZnO valence band. An analysis of the experimental data on the film cathodoluminescence and comparative studies of luminescence and electron spin resonance in single crystals allow one to conclude that the uncontrollable copper impurity typically existing in ZnO is responsible for green-emission luminescence in this material. (Read more)
- 64. J. Appl. Phys. 94, 519-524 (2003) , “Molecular nitrogen (N2-" align="middle">) acceptors and isolated nitrogen (N–) acceptors in ZnO crystals”, N. Y. Garces, Lijun Wang, N. C. Giles, L. E. Halliburton, G. Cantwell, D. B. EasonElectron paramagnetic resonance (EPR) has been used to investigate molecular nitrogen and isolated nitrogen acceptors in single crystals of ZnO. These samples were grown by the seeded chemical vapor transport method with N2 added to the gas stream. A five-line EPR spectrum is observed at... (Read more)
- 65. J. Phys. Chem. Solids 64, 1027-1035 (2003) , “Optical absorption and fluorescence properties of Er3+ ion in MO–WO3–P2O5 glasses”, P. Subbalakshmi , N. VeeraiahTungsten phosphate glasses mixed with the three different modifier oxides, viz. PbO, ZnO and CaO doped with Er2O3 were prepared. The glasses were characterised by X-ray diffraction spectra, electron microscopy and differential thermal analysis. Optical absorption and photoluminescence spectra of... (Read more)
- 66. Micro. Eng. 66, 59-64 (2003) , “Magnetic resonance studies on ZnO nanocrystals”, H. Zhou, A. Hofstaetter, D. M. Hofmann and B. K. MeyerZnO nanocrystals with diameters ranging from 4 to 50 nm were prepared via a wet chemical method and post-growth annealing treatments. The electron paramagnetic resonance (EPR) spectra of the nanocrystals show the resonance of electron centers with g-value close to that of the shallow donors in bulk... (Read more)
- 67. Physica B 340-342, 225-229 (2003) , “Optical absorption of a Li-related impurity in ZnO”, Deirdre Mc Cabe, Karl Johnston, Martin O. Henry, Enda Mc Glynn, Eduardo Alves and J. John DaviesA defect associated with Li in ZnO is reported. This is an optical system which absorbs strongly in the red part of the spectrum: a doublet, the zero phonon lines are at 1.884 and 1.879 eV, respectively. The chemical nature of the centre is identified through isotope substitution. This is the first... (Read more)
- 68. Appl. Phys. Lett. 81, 622 (2002) , “Role of copper in the green luminescence from ZnO crystals”, N. Y. Garces, L. Wang, L. Bai, N. C. Giles, L. E. Halliburton, G. CantwellElectron paramagnetic resonance (EPR), photoluminescence, and infrared optical absorption have been used to investigate a ZnO crystal before and after a thermal anneal for 1 h in air at 900 °C. The sample was an undoped high quality crystal grown by the chemical vapor transport method. In... (Read more)
- 69. Appl. Phys. Lett. 80, 1334 (2002) , “Production of nitrogen acceptors in ZnO by thermal annealing”, N. Y. Garces, N. C. Giles, L. E. Halliburton, G. Cantwell, D. B. Eason, D. C. Reynolds, D. C. LookNitrogen acceptors are formed when undoped single crystals of zinc oxide (ZnO) grown by the chemical-vapor transport method are annealed in air or nitrogen atmosphere at temperatures between 600 and 900 °C. After an anneal, an induced near-edge absorption band causes the crystals to appear... (Read more)
- 70. J. Phys. Chem. Solids 63, 555-559 (2002) , “OH− impurities in co-doped LiNbO3:Cr 3+:ZnO congruent crystals”, G. A. Torchia, J. O. Tocho , F. JaqueInfrared optical absorption has been used to study OH−impurities into congruent co-doped LiNbO3:Cr3+:ZnO crystals doped with different Zn2+ concentration. The OH− IR absorption spectra present three bands that can be associated with different OH− complex centres available in the... (Read more)
- 71. Mater. Sci. Eng. A 332, 356-361 (2002) , “The preparation and characterization of ZnO ultrafine particles”, Liqiang Jing, Zili Xu, Jing Shang, Xiaojun Sun, Weimin Cai and Haichen GuoIn this paper, ZnO ultrafine particles (UFPs) were prepared by the thermal decomposition method of the precursor, zinc carbonate hydroxide. The structure and properties of the as-prepared ZnO UFPs were studied using TEM, XRD, BET, SPS, ESR, Raman, XPS and UV–Vis absorption spectroscopy. It... (Read more)
- 72. Mater. Sci. Eng. B 94, 8-13 (2002) , “Annealing effects in ZnO and ZnO–SnO2 powders during grinding”, M. Kakazey, J. Sanchez-Mondragon, G. Gonzalez-Rodriguez, M. Vlasova, T. Sreckovic, N. Nikolic ,M. M. RisticWe report on the differences in the defect structure of ZnO particles that take place at the grinding of powders of pure ZnO and mixture ZnO–SnO2. The defect structure formed was studied by electron paramagnetic resonance (EPR). The results demonstrate that a sequential two-stage thermal... (Read more)
- 73. Phys. Rev. Lett. 88, 45504 (2002) , “Hydrogen: A Relevant Shallow Donor in Zinc Oxide”, Detlev M. Hofmann, Albrecht Hofstaetter, Frank Leiter, Huijuan Zhou, Frank Henecker, Bruno K. Meyer, Sergei B. Orlinskii, Jan Schmidt, Pavel G. BaranovElectron paramagnetic resonance and Hall measurements show consistently the presence of two donors ( D1 and D2) in state-of-the-art, nominally undoped ZnO single crystals. Using electron nuclear double resonance it is found that D1 shows hyperfine interaction with more than 50 shells of surrounding... (Read more)
- 74. Appl. Catalysis A 213, 173-177 (2001) , “In situ electron paramagnetic resonance (EPR) study of surface oxygen species on Au/ZnO catalyst for low-temperature carbon monoxide oxidation”, Zhengping Hao, Liangbo Fen, G. Q. Lu, Jianjun Liu, Lidun An and Hongli WangSome paramagnetic superoxide ions detectable by electron paramagnetic resonance (EPR) can be generated on Au/ZnO catalyst by oxygen adsorption at room temperature as well as at 553 K. In both the cases, the O2− ions are present on the catalyst surface. The disappearance of the O2−... (Read more)
- 75. Appl. Surf. Sci. 180, 308-314 (2001) , “The surface properties and photocatalytic activities of ZnO ultrafine particles”, Liqiang Jing, Zili Xu, Xiaojun Sun, Jing Shang and Weimin CaiWe prepared ZnO ultrafine particles (UFPs) by thermal decomposition of the precursor zinc carbonate hydroxide. The surface properties of the as-prepared particles were studied using TEM, XRD, BET, SPS, EPR, IR, and XPS. The surface contains active species such as oxygen deficiencies and hydroxyl... (Read more)
- 76. Physica B 308-310, 976-979 (2001) , “Magnetic resonance studies of ZnO”, W. E. Carlos, E. R. Glaser and D. C. LookWe have used EPR and ODMR to study state-of-the-art bulk ZnO single crystals. Most of the samples are n-type; however, under certain conditions (e-irradiated or annealed), we observe a center due to residual nitrogen (g||=1.9953, g=1.9633 and Aiso=1.225 mT, Aaniso=0.864 mT). The N center is a... (Read more)
- 77. Appl. Catalysis A 178, 167-176 (1999) , “Reactivity for isomerization of 1-butene on the mixed MoO3–ZnO oxide catalyst”, Kentaro Nakamura, Kazuo Eda, Sadao Hasegawa , Noriyuki SotaniThe mixed MoO3–ZnO catalyst was expected to reveal the new function as a catalyst. The catalyst was characterized by XRD, ESR, XANES and so on. We found that the MoO3–ZnO catalyst was effective for isomerization and metathesis of 1-butene. The defects with the anion vacancy were formed... (Read more)
- 78. Appl. Surf. Sci. 147, 85-93 (1999) , “Influence of trivalent metal ions on the surface structure of a copper-based catalyst for methanol synthesis”, Hong-Bo Chen, Dai-Wei Liao, La-Jia Yu, Yi-Ji Lin, Jun Yi, Hong-Bin Zhang and Khi-Rui TsaiThe method of doping trivalent metal ions into a copper-based catalyst for methanol synthesis is effective in modifying the surface structure of the catalyst. The promotion effect and its relation to catalytic activity for hydrogenation of CO to methanol after doping with trivalent metal ions such... (Read more)
- 79. Jpn. J. Appl. Phys. 38, L113 (1999) , “Yellow Emission from Zinc Oxide giving an Electron Spin Resonance Signal at g=1.96”, Naoki Ohashi, Tomokazu Nakata, Takashi Sekiguchi, Hideo Hosono, Masafumi Mizuguchi, Takaaki Tsurumi, Junzo Tanaka, Hajime HanedaZnO polycrystals doped with Li, Cu or Al were prepared by solid-state reactions and their cathodoluminescence (CL) and electron spin resonance (ESR) spectra were measured. A strong yellow emission centered at 2.0 eV was observed for the Al-doped specimen and its intensity was higher than that of... (Read more)
- 80. Solid State Commun. 112, 541-544 (1999) , “A new EPR centre of Er3+ in MgO or ZnO co-doped LiNbO3 single crystals”, D. Bravo, A. Martín , F. J. LópezElectron Paramagnetic Resonance (EPR) experiments have been carried out on congruent crystals of LiNbO3 heavily doped with Mg or Zn and co-doped with Er. In addition to the EPR spectrum previously observed in crystals of LiNbO3:Er3+ an erbium spectrum not reported before is detected in samples... (Read more)
- 81. J. Non-Cryst. Solids 241, 71-73 (1998) , “Long luminescent glass: Tb3+-activated ZnO–B2O–SiO2 glass”, Masaaki Yamazaki, Yoshinori Yamamoto, Shinobu Nagahama, Naruhito Sawanobori, Masafumi Mizuguchi , Hideo HosonoIt has been found that zinc borosilicate glasses 60ZnO–20B2O3–20SiO2 doped with 0.2 mol% Tb2O3 exhibit phosphorescence after exciting with 254 nm light. This phosphorescence arises from f–f transitions of Tb3+ ions and is observable by the eye, in the dark for up to 1 h after... (Read more)
- 82. Mater. Lett. 33, 247-250 (1998) , “Electron spin resonance properties of ZnO microcrystallites”, Baolong Yu, Congshan Zhu, Fuxi Gan , Yabin HuangThe preparation of ZnO microcrystallites using a microemulsion method and their electron spin resonance (ESR) properties are reported for the first time. It was found that the ZnO microcrystallite exhibits an ESR signal at room temperature, in contrast to that of bulk ZnO. The results confirmed that... (Read more)
- 83. Appl. Phys. Lett. 68, 403 (1996) , “Correlation between photoluminescence and oxygen vacancies in ZnO phosphors”, K. Vanheusden, C. H. Seager, W. L. Warren, D. R. Tallant, and J. A. VoigtBy combining electron paramagnetic resonance (EPR), optical absorption, and photoluminescence (PL) spectroscopy, a strong correlation is observed between the green 510 nm emission, the free-carrier concentration, and the density of singly ionized oxygen vacancies in commercial ZnO phosphor powders.... (Read more)
- 84. J. Appl. Phys. 79, 7983-7990 (1996) , “Mechanisms behind green photoluminescence in ZnO phosphor powders”, K. Vanheusden, W. L. Warren, C. H. Seager, D. R. Tallant, J. A. Voigt, B. E. GnadeWe explore the interrelationships between the green 510 nm emission, the free-carrier concentration, and the paramagnetic oxygen-vacancy density in commercial ZnO phosphors by combining photoluminescence, optical-absorption, and electron-paramagnetic-resonance spectroscopies. We find that the green... (Read more)
- 85. Phys. Lett. A 213, 89-92 (1996) , “Ground-state zero-field splitting of Mn2+ ions in ZnO and CdSe crystals”, Xiao-Yu KuangZnO and CdSe crystals have similar hexagonal wurtzite structures with a contraction along the c-axis of the crystal, but contrary electronic fine structures for ZnO:Mn2+ (D < 0) and CdSe:Mn2+ (D > 0) have been found in EPR experiments. We demonstrate that the ground-state splitting in ZnO:Mn2+... (Read more)
- 86. Appl. Phys. Lett. 67, 1280 (1995) , “Impact of Pb doping on the optical and electronic properties of ZnO powders”, K. Vanheusden, W. L. Warren, J. A. Voigt, C. H. Seager, and D. R. TallantElectron paramagnetic resonance (EPR), optical absorption, and photoluminescence (PL) spectroscopy have been combined to characterize Pb-doped ZnO ceramic powders. We observe a decrease in the 2.26 eV emission peak and a concomitant smearing of the band edges, narrowing the effective gap of the... (Read more)
- 87. Mater. Lett. 19, 53-56 (1994) , “The effect of NiO doping on the stoichiometry of ZnO”, P. Lot'k, J. Lounek, L. Koudelka, L. Bene and E. ernokováThe additions of NiO (0–2.0 mol%) to ZnO result in a decrease of the parameter c of its crystal lattice and its high-frequency electrical conductivity and in an elimination of the ESR band with g = 1.96. The observed changes were ascribed to the formation of Zn1−xNixO solid solution,... (Read more)
- 88. J. Catalysis 140, 585-600 (1993) , “Studies of Gas Adsorption on ZnO Using ESR, FTIR Spectroscopy, and MHE (Microwave Hall Effect) Measurements”, Na B. K., Walters A. B. and Vannice M. A.This paper describes the application of a new technique-Microwave Hall Effect (MHE) measurements-to measure electron mobilities and to determine the effect of adsorption on electron densities of powders. Conduction electron densities calculated from microwave measurements of both mobilities and... (Read more)
- 89. Phys. Rev. B 46, 12266-12277 (1992) , “Measurement of the effect of pretreatment and adsorption on the electrical properties of ZnO powders using a microwave-Hall-effect technique”, Byung-Ki Na, M. Albert Vannice, Arden B. WaltersMicrowave-Hall-effect (MHE) and electrical conductivity measurement techniques can now be used to obtain absolute values of the electrical properties of semiconductor powders under different controlled conditions. A commercial ESR spectrometer was modified to conduct MHE experiments and a network... (Read more)
- 90. Appl. Phys. Lett. 58, 1742 (1991) , “Electron spin resonance study of laser-annealed (Zn,Mn)O ceramics”, Katsuyasu Kawano, Ryouhei Nakata, and Minoru SumitaInvestigations have been made on the effects of pulse laser annealing on the ceramics (Zn,Mn)O by means of electron spin resonance (ESR) measurements. A remarkable change in the ESR spectrum was observed after annealing by a Nd:YAG pulse laser (=1.064 µm, 57 J/cm2). It... (Read more)
- 91. Vacuum 41, 1633-1635 (1990) , “Characterization of defects on ZnO and Ru---ZnO: a structural, TPD, and spectroscopic study”, M. G. CattaniaP. d'AntonaF. Morazzoni and R. ScottiSurface and bulk defects in ZnO were recognized as interstitial zinc atoms and surface oxygen vacancies (V0)s by means of XRD, SEM, TPD and ESR measurements. Dispersion of ruthenium at the ZnO surface induces an electron transfer from ZnO defects to the metal as revealed by ESR and XPS spectroscopy. (Read more)
- 92. J. Non-Cryst. Solids 111, 16-28 (1989) , “Mechanism of photochromism in oxide glasses containing a large amount of CdO or ZnO”, H. Kawazoe, R. Suzuki, S. Inoue and M. YamaneUV-induced optical and ESR absorptions of borosilicate glasses containing a large amount ( 50 mol%) of CdO or ZnO were measured at room temperature and 77 K while changing the wavelength of the illuminating light. The induced optical absorption was one order of magnitude stronger at 77 k than at... (Read more)
- 93. J. Catalysis 111, 199-209 (1988) , “Structural analysis of ZnO/ZnCr2O4/Pd catalyst”, Lucio ForniThe ZnO/ZnCr2O4/Pd mixture is an effective catalyst for the preparation of pyrazines from diamines and glycols. The effects of the method of preparation, the Zn/Cr ratio, and the concentration of Pd have been studied by analyzing the catalyst structure using several techniques. In the coprecipitated... (Read more)
- 94. Appl. Catalysis 21, 133-147 (1986) , “Investigation on the state of copper in copper-zinc oxide biphasic catalyst by EPR and adsorption microcalorimetry”, E. Giamello, B. Fubini and P. LauroBinary Cu---ZnO catalysts active for methanol synthesis and the CO shift reaction were studied by EPR and by adsorption calorimetry. The EPR spectrum of Cu(II) in the calcined catalyst (CuO---ZnO) was studied, and also its evolution on reduction of the calcined into the reduced form... (Read more)
- 95. Prog. Surf. Sci. 20, 9-103 (1985) , “Chemisorption and charge transfer at ionic semiconductor surfaces: Implications in designing gas sensors”, W. GopelA detailed atomistic understanding of charge transfer reactions between semiconductor surfaces and adsorbing particles is essential for designing gas sensors or metal-oxide catalysts.This will be demonstrated in a discussion of thermodynamically or kinetically controlled solid/gas interactions at... (Read more)
- 96. J. Cryst. Growth 59, 363-369 (1982) , “Electron spin resonance and cathodoluminescence in ZnO”, T. Wada, S. Kikuta, M. Kiba, K. Kiyozumi, T. Shimojo and M. KakehiThe ZnO samples were prepared by firing at 900°C, finely powdered material under different degrees of reduction. Measurements of the green cathodoluminescence (CL) were done by using a vacuum fluorescent display. The g values of ESR spectrum measured from the powders at 77 K were g|| =... (Read more)
- 97. J. Cryst. Growth 59, 357-362 (1982) , “Magnetic resonance studies of shallow donors in zinc oxide”, C. Gonzalez, D. Block, R. T. Cox and A. HervéShallow donors in ZnO were studied by electron spin resonance (ESR) and optically detected magnetic resonance (ODMR). Indium and gallium donors were identified by their hyperfine structure. They have g|| = 1.957 and g = 1.956 and the hyperfine constants are A(69Ga)=4.2 and A(115In)=36.6 G. The ESR... (Read more)
- 98. Thermochim. Acta 29, 247-252 (1979) , “Combined EPR and TG techniques : comparison of the thermal reduction of chromium (VI) ions in some zinc chromates and chromate-oxalate mixtures*1”, Z. Gabelica , E. G. DerouaneR. HubinLower oxydation state chromium species which are successively formed and stabilized upon thermal reduction of chromate (VI) ions, are studied by combined EPR and TG-techniques.The spontaneous oxygen release occuring during the vacuum thermal treatment of some zinc chromates leads to the formation of... (Read more)
- 99. J. Vac. Sci. Technol. 15, 1298-1310 (1978) , “Reactions of oxygen with ZnO–100-surfaces”, W. GöpelInvestigations are reported on the reaction of oxygen with electrostatic neutral ZnO100-surfaces studied by means of AES, LEED, EPR, thermal desorption spectroscopy, and isotopic exchange as well as changes in the surface conductivity and work function. Geometric and electronic structures of... (Read more)
- 100. Solid State Commun. 26, 779-781 (1978) , “Motional effects in the EPR-spectrum of Cu-H-centers in ZnO”, D. ZwingelAt low temperatures, the EPR signal of a Cu2+ center is observed in ZnO single crystals doped both with copper and hydrogen. A clear effect of line narrowing on the copper hfs-lines is observed at T=16K. It is discussed in the model of a Cu-(OH) complex taking into account the thermally induced... (Read more)
- 101. Solid State Commun. 25, 77-80 (1978) , “Exchange broadened, optically detected ESR spectra for luminescent donor-acceptor pairs in Li doped ZnO”, R. T. Cox, D. Block, A. Hervé, R. Picard and C. SantierR. HelbigApplication of optically detected ESR to the yellow photoluminescence of Li doped ZnO gives ESR spectra for shallow donor - lithium acceptor pairs, showing that at least a fraction of the yellow emission is donor-acceptor (D-A) luminescence. The distribution of separations rDA gives a spectrum of... (Read more)
- 102. J. Lumin. 12-13, 441-445 (1976) , “ESR and luminescence of trapped hole centers in ZnO and SnO2”, E. Mollwo , D. ZwingelIn SnO2 single crystals acceptor centers are found upon incorporation of Al3+ and Ga3+ ions at cation sites. After UV-excitation, holes, trapped at these centers, give rise to polarized luminescence and thermoluminescence. The structure of the centers is analysed by ESR and compared with similar... (Read more)
- 103. Z. Physik B 23, 171-181 (1976) , “Intrinsic Defects in Electron Irradiated Zinc Oxide”, B. Schallenberge, A. Hausmann
- 104. J. Catalysis 35, 167-175 (1974) , “Studies of electron spin resonance spectra and activity of supported zinc oxide catalysts for hydrogenation of ethylene”, D. L. Harrison, A. J. Parker, Marjorie J. Sharp and H. SteinerThe activities and ESR spectra of zinc oxide catalysts for hydrogenation of ethylene at 150 °C have been studied. No catalytic activity was observed for silica- or alumina-supported ZnO at surface coverages below 2–3 nominal monolayers. The ESR signal at g = 1.958 from the zinc oxide was... (Read more)
- 105. J. Chem. Phys. 60, 2148-2151 (1974) , “Formation of O– in ZnO from the dissociation of adsorbed N2O”, Ning-Bew Wong, Younes Ben Taarit, and Jack H. LunsfordPhotoinduced O ions or V-type centers have been detected in ZnO following ultraviolet irradiation at 196°C. The EPR spectrum of the ions is characterized by g=2.021 and g = 2.0026. The concentration of O was greatly... (Read more)
- 106. Solid State Commun. 15, 1475-1479 (1974) , “Optical and paramagnetic properties of ZnO-Crystals simultaneously doped with copper and hydrogen”, E. Mollwo, G. Müller and D. ZwingelIn ZnO crystals, containing both Cu and H(D), we observe characteristic absorption peaks in the near i.r. and three new EPR signals. We explain these results by the formation of impurity complexes consisting of an OH center and one or two Cu ions. (Read more)
- 107. Solid State Commun. 14, 953-956 (1974) , “Temperature dependence of the ESR spectrum of the zinc vacancy in ZnO”, D. Galland and A. HerveThe temperature dependence of the spectrum of two trapped hole centers introduced by electron irradiation in ZnO is described. The results firmly establish the identification of these centers as being two slightly inequivalent configurations of the zinc vacancy in its negative charge state. (Read more)
- 108. Solid State Commun. 14, 45-49 (1974) , “Paramagnetic and optical properties of Na-doped ZnO single crystals”, D. Zwingel and F. GärtnerESR-spectra of Na-doped ZnO single crystals are reported, caused by a hole trapped at the Na+ center. The isotropic part of the HFS is positive. An emission, due to recombination at the center, is reported, polarized c and peaked at 570 nm. The influence of covalent bonding is discussed. (Read more)
- 109. Advances in Molecular Relaxation Processes 5, 211-218 (1973) , “Chemisorption of oxygen on transition metal oxides studied by EPR”, Krystyna DyrekThe method was applied to the investigation of adsorption of oxygen on the transition metal oxides MnO, FeO, CoO, Cu2O, and their solid solutions in the diamagnetic matrices ZnO and MgO. It has been found that in the case of pure oxides and their solid solutions at high magnetic metal ion... (Read more)
- 110. Chem. Phys. Lett. 21, 421-425 (1973) , “ESR studies of aqueous suspensions of zinc oxide”, Joseph Cunningham and Sean CorkeryResults are presented from a technique which allows reproducible ESR spectra to be obtained from circulating aqueous suspensions of various zinc oxides. Singlet ESR signals with g ≈ 1.96 were observed in the dark from In-ZnO and from several zinc oxides under UV illumination. Fast and slow... (Read more)
- 111. J. Lumin. 6, 376-384 (1973) , “2S1/2 state ions in inorganic luminescent materials*1”, G. Born, A. Hofstaetter , A. ScharmannSelected examples of impurity ions with one unpaired electron in an unfilled shell are Pb3+ ions in II–IV compounds (ZnO, ZnSe, ZnTe), Pb3+ in CaWO4,F centres in alkali halides and Ag0 and Au0 atoms in radiophotoluminescent (RPL) glasses. Comparative studies of EPR, luminescence,... (Read more)
- 112. J. Lumin. 5, 385-405 (1972) , “Trapping and recombination processes in the thermoluminescence of Li-doped ZnO single crystals*1”, D. ZwingelThe thermoluminescence of Li-doped ZnO single crystals is investigated in the temperature range 4.2–300 K. A glow curve is observed with three maxima, two of them emitting the strong polarized yellow luminescence of ZnO. By varying the Li concentration in the range 0.1–200 ppm a change... (Read more)
- 113. J. Vac. Sci. Technol. 9, 87-90 (1972) , “Properties of ZnO Films Prepared by dc and rf Diode Sputtering”, J. VuillodA brief description of the dc and rf diode sputtering unit is first presented. The study of properties of the films is reviewed taking into consideration two main parameters, oxygen partial pressure and substrate temperature. Reflection electron diffraction and x-ray diffraction studies show that... (Read more)
- 114. Solid State Commun. 11, 1547-1550 (1972) , “Oxygen displacement energy in ZnO”, J. M. MeeseD. R. LockerA displacement threshold at 310 keV has been observed by electrical measurements in single crystal ZnO and has been identified as the minimum electron energy required for oxygen displacements by observing the production of F- centers above this threshold with EPR. (Read more)
- 115. J. Phys. Chem. Solids 32, 499-509 (1971) , “Trapped-hole centers containing lithium in MgO, CaO and SrO”, O. F. SchirmerWe report an ESR investigation of a center in MgO, CaO and SrO consisting of an O− ion neighbored by a substitutional Li+ ion. The center is identified by comparison with the isomorphous centers in ZnO and BeO and with the analogous V1, VOH and VF centers in the alkaline earth oxides. The... (Read more)
- 116. Phys. Lett. A 36, 447-448 (1971) , “2S1/2 -states of Pb3+-ions in CaO and ZnO”, G. Born, A. Hofstaetter , A. ScharmannEPR-spectra of Pb3+-ions in CaO and ZnO are studied at 1.6 K. The g-values and the reduction of the hyperfine interaction constants A are correlated with the partial electron transfer to the ligands. (Read more)
- 117. Phys. Rev. B 4, 3250-3252 (1971) , “Spin-Hamiltonian Parameters and Spin-Orbit Coupling for V3+ in ZnO”, R. E. Coffman, Makram I. Himaya, Kathryn NyeuThe spin-Hamiltonian parameters for ZnO: V3+ have been refined using electron-paramagnetic-resonance (EPR) line position calculations. The principal sources of error are discussed. The accurate spin-Hamiltonian parameters are used to discuss the spin-orbit coupling within the 3d manifold... (Read more)
- 118. Solid State Commun. 9, 2251-2253 (1971) , “Far infrared absorption in ZnO*1”, S. Perkowitz, R. K. Murty-Gutta , A. K. GarrisonFar infrared absorption measurements on as-grown and Li-doped ZnO have been made in the range 15-200 cm−1. A large Drude-type free-carrier absorption was observed, as were absorption bands near 115 and 160 cm−1. Combined absorption and EPR data on the Li-doped sample were interpreted... (Read more)
- 119. Surf. Sci. 27, 375-378 (1971) , “ESR evidence of surface Fermi level anchoring by surface additives on ZnO”, J. P. Bonnelle and M. Guelton
- 120. J. Catalysis 16, 44-52 (1970) , “Electron spin resonance investigation of electrical conductivity parameters of zinc oxide during surface reactions”, Morio Setaka, Kenneth M. Sancier and Takao KwanThe effect of the electron transfer process between the bulk and surface of ZnO upon oxygen sorption was investigated by measuring the changes of the following ESR parameters: the spin densities of the g = 1.96 and g ~ 2.0 signals, the intensity of a Mn2+ reference sample, and the crystal current of... (Read more)
- 121. Phys. Lett. A 33, 1-2 (1970) , “ESR spectra of the zinc vacancy in ZnO”, D. Galland and A. HerveElectron irradiated ZnO single crystals show anisotropic ESR spectra corresponding to a spin and a spin 1 hole centers. Tehy are respectively identified as the negative and the neutral charge states of the zinc vacancy. (Read more)
- 122. Phys. Lett. A 31, 147-148 (1970) , “ESR of electron irradiated ZnO confirmation of the F+ center”, J. M. Smith , W. E. VehseIrradiation of single crystals of ZnO with 2 MeV electrons produces a defect which has been identified by its ESR spectrum as an F+ center. A correlation between this center and the radiation induced optical absorption has been observed. (Read more)
- 123. Phys. Rev. B 1, 1986-1994 (1970) , “Electron Paramagnetic Resonance of V3 + Ions in Zinc Oxide”, G. Filipovich, A. L. Taylor, R. E. CoffmanThe paramagnetic resonance of trace amounts of V3+ in single-crystal hexagonal zinc oxide is reported. The EPR spectrum is fitted with an axially symmetric spin Hamiltonian with five empirically determined parameters: D, gII, g?, A, and B. The spin-Hamiltonian... (Read more)
- 124. Solid State Commun. 8, 45-47 (1970) , “A note on the splitting of the ( →← -) line in the ESR spectrum of Fe3+ in ZnO”, I. D. Campbell , J. O. CopeIons of spin which occupy inequivalent cation sites in a wurtzite lattice show ESR line splitting. An analytical expression is derived which describes the dependence of the splitting of the ( →← -) line on crystal orientation. This expression provides a convenient method of deducing... (Read more)
- 125. Solid State Commun. 8, 1559-1563 (1970) , “The yellow luminescence of zinc oxide”, O. F. Schirmer and D. ZwingelFrom a simultaneous observation of the ESR of the paramagnetic Li center and the yellow emission of ZnO, especially its polarization, it is concluded that this luminescence band is due to a recombination of an electron with the neutral Li acceptor. (Read more)
- 126. Solid State Commun. 8, 1359-1361 (1970) , “Electron paramagnetic resonance associated with Zn vacancies in neutron-irradiated ZnO”, A. L. Taylor, G. Filipovich and G. K. LindebergLines in the EPR spectrum of ZnO crystals irradiated by 3.6 × 1018cm−2 fast neutrons are ascribed to holes on oxygen atoms in the basal plane of O4 tetrahedra which surround Zn vacancies. (Read more)
- 127. Solid State Commun. 8, 1103-1106 (1970) , “ESR studies of Yb3+ impurities in zinc oxide”, P. Schreiber , A. HausmannIn zinc oxide single crystals after diffusion with Yb2O3 two ESR spectra of Yb3+ ions have been observed which are attributed to substitutional and possibly interstitial ions. The parameters of the spin Hamiltonian have been determined taking into account third order corrections and a relatively... (Read more)
- 128. Surf. Sci. 21, 1-11 (1970) , “ESR investigation of photodamage to zinc oxide powders*1”, K. M. SancierThe esr technique was used to investigate the effects of iron cyanide surface additives on photodamage to ZnO in powder form. The photodamage was monitored by the resonance at a g value of about 1.96, which is comprised of two independent resonances with g values of 1.9564 and 1.9600. The intensity... (Read more)
- 129. Solid State Commun. 7, 651-655 (1969) , “Elektronenspinresonanz an kupferdotierten ZnO-einkristallen”, I. Broser and M. SchulzESR-Untersuchungen wurden an ZnO:Cu-Einkristallen zwischen 4,2 und 1,5°K durchgeführt. Die den natürlich vorkommenden Isotopen 63Cu und 65Cu entsprechenden Hyperfeinstrukturlinien hatten eine deutlich geringere Linienbreite verglichen mit bisherigen Messungen. Die... (Read more)
- 130. Solid State Commun. 7, 579-583 (1969) , “Paramagnetic resonance of Gd3+ in ZnO”, A. HausmannZnO single crystals doped with Gd3+ by diffusion have been investigated by ESR at 35kMc/s. The spectra can be understood by a spin-Hamiltonian of axial symmetry. Further, a hyperfine interaction with odd Gd isotopes has been detected. An asymmetry of one set of finestructure lines indicates a... (Read more)
- 131. Surf. Sci. 13, 251-262 (1969) , “ESR studies of the interaction of O2, NO2, N2O, NO and Cl2 with zinc oxide”, R. D. Iyengar, V. V. Subba Rao , A. C. ZettlemoyerAn electron spin resonance study of the surface interaction of zinc oxide with oxygen, oxides of nitrogen (NO2, NO and N2O) and chlorine was made. Characteristic spectra obtained following adsorption of NO2 and NO were analyzed and attributed to rigidly adsorbed neutral molecules. Confirmation of... (Read more)
- 132. J. Catalysis 12, 278-280 (1968) , “An ESR investigation of nitrobenzene adsorbed on zinc oxide”, V. V. Subba Rao, R. D. Iyengar and A. C. ZettlemoyerAn ESR study of the interaction of nitrobenzene with nonstoichiometric ZnO surfaces was made. A 3-line spectrum with g values 1.9840, 2.0055 and 2.0225 was observed and was identified as due to nitrobenzene anion radicals strongly held to the surface. An unidentified signal at g = 2.0050 was left... (Read more)
- 133. J. Catalysis 11, 317-325 (1968) , “ESR studies on ZnO---Cr2O3 catalysts”, M. RálekW. Gunsser , A. KnappwostThe effects of the conditions of preparation of ZnO---Cr2O3 catalysts on their ESR spectra have been investigated by means of a Q-band spectrometer. The linewidths of oxides prepared by a low-temperature decomposition of the respective hydroxides in nitrogen flow are large and exhibit concentration... (Read more)
- 134. J. Phys. Chem. Solids 29, 1407-1429 (1968) , “The structure of the paramagnetic lithium center in zinc oxide and beryllium oxide”, O. F. SchirmerIf ZnO and BeO crystals containing Li are irradiated with u.v. or X-rays, a paramagnetic defect center is created consisting of a hole captured at an O2− ion next to a substitutional Li+ impurity. Because of the polarity of the crystals, the hole assumes its lowest energy, if the... (Read more)
- 135. J. Phys. Chem. Solids 29, 1369-1375 (1968) , “Paramagnetic resonance of ZnO:Mn++ single crystals”, A. Hausmann , H. HuppertzZnO single crystals doped with Mn++ have been investigated by ESR at 9.5 and 35 kMc/s. The measured spectra show minimal linewidth of 0.25 G. The resonances can theoretically be described by a spin Hamiltonian of axial symmetry of which the parameters have been determined with great accuracy.... (Read more)
- 136. Solid State Commun. 6, 457-459 (1968) , “The cubic field parameter of ions in zinc oxide crystals”, A. HausmannZnO single crystals doped with Fe3+ or Mn2+ have been investigated by ESR at 35 kMc/s. The cubic field parameter |a| has been determined with greater accuracy than before. The values are |a| = 7.1 G and |a| = 46.8 G for Mn2+ and Fe3+ respectively. Further, considerations about the macroscopic... (Read more)
- 137. J. Catalysis 9, 331-335 (1967) , “ESR evidence of CO oxidation by more than one oxygen species sorbed on ZnO”, Kenneth M. SancierAn approach is described for investigating the nature of sorbed oxygen species on a semiconductor catalyst surface and for determining their relative reactivities in a heterogeneous oxidation reaction. Experimental information as to the types of oxygen species on ZnO with presorbed oxygen, ZnO... (Read more)
- 138. J. Catalysis 6, 411-418 (1966) , “Radiation-induced catalytic conversions : Organic compounds adsorbed on solids of different electronic properties”, G. M. Zhabrova, V. I. Vladimirova, B. M. Kadenatsi, V. B. Kazanskii , G. B. PariiskiiThe low-temperature radiation-induced conversions of methanol and cyclohexane adsorbed on solids were investigated. The solids used were dielectrics (SiO2, silica-alumina, Al2O3, KF), semiconductors (ZnO, NiO), and metals (Pt, Pd). The samples were irradiated by γ-rays from Co60 at a dose rate... (Read more)
- 139. J. Catalysis 5, 314-324 (1966) , “ESR investigation of gas-solid interactions* The oxygen-zinc oxide system”, K.M. SancierESR measurements were combined with determinations of the amount of oxygen adsorbed or desorbed on ZnO in order to investigate the relationship between the solid state electronic properties of a semiconductor catalyst and the amounts and the nature of the adsorbed oxygen species. (Read more)
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