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- 1. Phys. Rev. B 75, 193409 (2007) , “Magnetic properties of vacancies in a graphitic boron nitride sheet by first-principles pseudopotential calculations”, M. S. Si and D. S. XueWe use ab initio methods to calculate the magnetic properties of vacancies in a graphitic boron nitride sheet (g-BN). By applying a full spin-polarized description to the system, we demonstrate that the nitrogen vacancy (VN) or the boron vacancy (VB)... (Read more)
- 2. Phys. Rev. B 75, 193201 (2007) , “Compensating point defects in 4He+-irradiated InN”, F. Tuomisto, A. Pelli, K. M. Yu, W. Walukiewicz, and W. J. SchaffWe use positron annihilation spectroscopy to study 2 MeV 4He+-irradiated InN grown by molecular-beam epitaxy and GaN grown by metal-organic chemical-vapor deposition. In GaN, the Ga vacancies act as important compensating centers in the irradiated material, introduced at a... (Read more)
- 3. Phys. Rev. B 75, 144102 (2007) , “Theoretical investigation of nitrogen substitution in cubic zirconia”, Thomas BredowNitrogen substitution of oxygen ions in cubic zirconia was studied theoretically at density functional level. Nitrogen contents of 12.5 and 3.1% were studied with Zr8O16−mN2 and Zr32O64−mN2 supercells. For... (Read more)
- 4. Appl. Phys. Lett. 89, 061903 (2006) , “Nitrogen related vacancies in GaAs based quantum well superlattices”, J. Slotte, K. Saarinen, E.-M. Pavelescu, T. Hakkarainen, and M. PessaThe authors report on the influence of nitrogen incorporation on vacancies in GaAs based superlattices. The samples were molecular beam epitaxy grown on p-type GaAs substrates with the superlattice structure consisting of ten periods of quantum well material separated by GaAs buffers. Three... (Read more)
- 5. Appl. Phys. Lett. 89, 053511 (2006) , “Density functional theory study of deep traps in silicon nitride memories”, Max Petersen and Yakov RoizinUsing density functional theory, the interaction of hydrogen with a nitrogen vacancy in -Si3N4 is investigated. A single H atom was found to be energetically favorable over non- and doubly protonated vacancies. The traps composed of excess silicon and hydrogen have negative... (Read more)
- 6. J. Appl. Phys. 100, 113513 (2006) , “Theoretical study of nitrogen-doping effects on void formation processes in silicon crystal growth”, Hiroyuki Kageshima, Akihito Taguchi, and Kazumi WadaNitrogen-doping effects in silicon crystal growth have been theoretically studied using thermodynamical simulation based on first-principles calculation results. The results show that the densities of various complexes are determined in the balance between the enthalpy effects and the entropy... (Read more)
- 7. J. Appl. Phys. 99, 113506 (2006) , “Theoretical properties of the N vacancy in p-type GaN(Mg,H) at elevated temperatures”, S. M. Myers, A. F. Wright, M. Sanati, and S. K. EstreicherThe elevated-temperature properties of the N vacancy in Mg-doped, p-type GaN containing H were modeled using atomic-configuration energies and phonon densities of states obtained with density-functional theory. This study encompassed both equilibrium thermodynamics and the rates of diffusion... (Read more)
- 8. J. Appl. Phys. 99, 044105 (2006) , “Passivation of oxygen vacancy states in HfO2 by nitrogen”, K. Xiong, J. Robertson, and S. J. ClarkNitrogen is known to reduce leakage currents and charge trapping in high-dielectric-constant gate oxides such as HfO2. We show that this occurs because nitrogen, substituting for oxygen atoms next to oxygen vacancy sites, repels the occupied gap states due to the neutral and positively... (Read more)
- 9. 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)
- 10. Phys. Rev. B 74, 165404 (2006) , “Density functional study of gold atoms and clusters on a graphite (0001) surface with defects”, Jaakko Akola and Hannu HäkkinenAdsorption of gold atoms and clusters (N=6) on a graphite (0001) surface with defects has been studied using density functional theory. In addition to perfect graphite (0001), three types of surface defects have been considered: a surface vacancy (hole), a pyridinelike defect comprising three... (Read more)
- 11. Phys. Rev. B 74, 161203(R) (2006) , “Room-temperature manipulation and decoherence of a single spin in diamond”, R. Hanson, O. Gywat, and D. D. AwschalomWe report on room-temperature coherent manipulation of the spin of a single nitrogen-vacancy center in diamond and a study of its coherence as a function of magnetic field. We use magnetic resonance to induce Rabi nutations and apply a Hahn spin echo to remove the effect of low-frequency dephasing.... (Read more)
- 12. Phys. Rev. B 74, 155204 (2006) , “Vibronic spectrum of c-BN measured with cathodoluminescence”, C. Manfredotti, R. Cossio, A. Lo Giudice, E. Vittone, and F. FizzottiAn extended vibronic spectrum (up to six phonon replicas) has been measured by low temperature cathodoluminescence in pure c-BN microcrystalline samples obtained by high temperature high pressure method. The zero phonon line, found at 3.573 eV, should be connected to a center identified... (Read more)
- 13. Phys. Rev. B 74, 153403 (2006) , “Doping and the unique role of vacancies in promoting the magnetic ground state in carbon nanotubes and C60 polymers”, Antonis N. Andriotis, R. Michael Sheetz, and Madhu MenonThe role of various types of defects in establishing the magnetic properties of the C60-based polymers and the single-wall carbon nanotubes is investigated. Comparing the role of carbon vacancies, and that of substitutional impurity atoms X (X=N, B, O, Si, P, and S) in... (Read more)
- 14. 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)
- 15. Phys. Rev. B 74, 104303 (2006) , “Nitrogen-vacancy center in diamond: Model of the electronic structure and associated dynamics”, N. B. Manson, J. P. Harrison, and M. J. SellarsSymmetry considerations are used in presenting a model of the electronic structure and the associated dynamics of the nitrogen-vacancy center in diamond. The model accounts for the occurrence of optically induced spin polarization, for the change of emission level with spin polarization and for new... (Read more)
- 16. Phys. Rev. Lett. 96, 145501 (2006) , “Identification of the Carbon Antisite-Vacancy Pair in 4H-SiC”, T. Umeda, N. T. Son, J. Isoya, E. Janzn, T. Ohshima, N. Morishita, H. Itoh, A. Gali, M. BockstedteThe metastability of vacancies was theoretically predicted for several compound semiconductors alongside their transformation into the antisite-vacancy pair counterpart; however, no experiment to date has unambiguously confirmed the existence of antisite-vacancy pairs. Using electron paramagnetic resonance and first principles calculations we identify the SI5 center as the carbon antisite-vacancy pair in the negative charge state (CSiVC-) in 4H-SiC. We suggest that this defect is a strong carrier-compensating center in n-type or high-purity semi-insulating SiC. (Read more)SiC| ENDOR EPR Theory electron-irradiation optical-spectroscopy thermal-meas./anneal-exp.| -1 -2 1.0eV~ 13C 29Si C1h C3v Carbon Csi EI5/6 HEI1 HEI5/6 Nitrogen P6/7 SI5 Silicon Vc antisite bistable/metastable dangling-bond n-type pair(=2) semi-insulating vacancy .inp files: SiC/SI5_C1h SiC/SI5_80K SiC/SI5_100K | last update: Takashi Fukushima
- 17. Appl. Phys. Lett. 86, 143507 (2005) , “First-principles studies of the intrinsic effect of nitrogen atoms on reduction in gate leakage current through Hf-based high-k dielectrics”, N. Umezawa, K. Shiraishi, T. Ohno, H. Watanabe, T. Chikyow, K. Torii, K. Yamabe, K. Yamada, H. Kitajima, T. ArikadoThe atomistic effects of N atoms on the leakage current through HfO2 high-k gate dielectrics have been studied from first-principles calculations within the framework of a generalized gradient approximation (GGA). It has been found that the intrinsic effects of N atoms drastically... (Read more)
- 18. J. Appl. Phys. 97, 053704 (2005) , “The role of nitrogen-related defects in high-k dielectric oxides: Density-functional studies”, J. L. Gavartin, A. L. Shluger, A. S. Foster, G. I. BersukerUsing ab initio density-functional total energy and molecular-dynamics simulations, we study the effects of various forms of nitrogen postdeposition anneal (PDA) on the electric properties of hafnia in the context of its application as a gate dielectric in field-effect transistors. We... (Read more)
- 19. Phys. Rev. B 70, 085202 (2004) , “Reassignment of phosphorus-related donors in SiC”, E. Rauls, M. V. B. Pinheiro, S. Greulich-Weber, and U. GerstmannCombining efficient density-functional based tight-binding molecular dynamics with ab initio calculations, we show that despite higher formation energies the incorporation of phosphorus at the carbon sublattice is favored by kinetic effects during the annealing processes. Based on the... (Read more)
- 20. Phys. Rev. Lett. 92, 135502 (2004) , “Hydrogen Incorporation in Diamond: The Vacancy-Hydrogen Complex”, C. Glover, M. E. Newton, P. M. Martineau, S. Quinn, D. J. TwitchenWe report the identification of the vacancy-hydrogen complex in single crystal diamond synthesized by chemical vapor deposition. The S = 1 defect is observed by electron paramagnetic resonance in the negative charge state. The hydrogen atom is bonded to one of the carbon atoms neighboring the... (Read more)
- 21. Phys. Rev. B 68, 085202 (2003) , “Physics and chemistry of hydrogen in the vacancies of semiconductors”, Bernadett Szûcs, Adam Gali, Zoltán Hajnal, Peter Deák, and Chris G. Van de WalleHydrogen is well known to cause electrical passivation of lattice vacancies in semiconductors. This effect follows from the chemical passivation of the dangling bonds. Recently it was found that H in the carbon vacancy of SiC forms a three-center bond with two silicon neighbors in the vacancy, and... (Read more)
- 22. Phys. Rev. B 67, 205202 (2003) , “Formation and annealing of nitrogen-related complexes in SiC”, U. Gerstmann, E. Rauls, Th. Frauenheim, and H. OverhofWe propose a mechanism for the annealing of vacancy-related defects in SiC, based on ab initio total energy calculations. Our mechanism is based on the formation and migration of carbon and nitrogen split interstitials resulting in CSi(NC)n or... (Read more)
- 23. Phys. Rev. Lett. 90, 137402 (2003) , “Vacancy Defects as Compensating Centers in Mg-Doped GaN”, S. Hautakangas, J. Oila, M. Alatalo, K. Saarinen, L. LIszkay, D. Seghier, H.P. GislasonWe apply positron annihilation spectroscopy to identify VNMgGa complexes as native defects in Mg-doped GaN. These defects dissociate in postgrowth annealings at 500800 °C. We conclude that VNMgGa complexes contribute to... (Read more)
- 24. Physica B 340-342, 15-24 (2003) , “Defects in SiC”, E. Janz?n, I. G. Ivanov, N. T. Son, B. Magnusson, Z. Zolnai, A. Henry, J. P. Bergman, L. Storasta, F. CarlssonRecent results from studies of shallow donors, pseudodonors, and deep level defects in SiC are presented. The selection rules for transitions between the electronic levels of shallow donors in 4H–SiC in the dipole approximation are derived and the ionization energy for the N donor at... (Read more)
- 25. Appl. Phys. Lett. 81, 1818 (2002) , “Interface structures generated by negative-bias temperature instability in Si/SiO2 and Si/SiOxNy interfaces”, J. Ushio, T. Maruizumi, K. Kushida-AbdelghafarWe used a density functional method to investigate the mechanism of negative-bias temperature instability (NBTI) and resultant structural changes of Si/SiO2 and Si/SiOxNy interfaces. The reaction energies for the water- and hydrogen-originated... (Read more)
- 26. Appl. Phys. Lett. 80, 410 (2002) , “The level position of a deep intrinsic defect in 4H-SiC studied by photoinduced electron paramagnetic resonance”, M. E. Zvanut and V. V. KonovalovPhotoinduced electron paramagnetic resonance studies performed on nominally semi-insulating, high purity 4H-SiC have revealed charge transfer from an intrinsic defect (ID) to both the shallow boron acceptor and nitrogen donor. At 4 K, incident photon energy between 1.0 and 1.7 eV produces an... (Read more)
- 27. Phys. Rev. B 59, 10823-10829 (1999) , “Defect energy levels in electron-irradiated and deuterium-implanted 6H silicon carbide”, M. O. Aboelfotoh, J. P. DoyleUsing deep-level transient spectroscopy, we studied defect energy levels and their annealing behavior in nitrogen-doped 6H-SiC epitaxial layers irradiated with 2-MeV electrons and implanted with 300-KeV deuterium or hydrogen at room temperature. Five levels located at Ec-0.34,... (Read more)
- 28. Phys. Rev. B 59, 10603 (1999) , “Defect characterization in electron-irradiated 6H-SiC by positron annihilation”, A. Polity, S. Huth, M. LausmannIsochronal annealing investigations in electron-irradiated 6H-SiC were correlated with temperature-dependent measurements of positron lifetime. It turned out that the positron trapping at temperatures up to 300 K was dominated by the trapping in shallow positron traps. These defects were already... (Read more)
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