¹¹⁹Sn NMR studies were carried out for metallic tin confined within synthetic opal and porous glass. Tin was embedded into nanoporous matrices in the melted state under pressure. The Knight shift for liquid confined tin was found to decrease with decreasing pore size. Correlations between... (Read more)

A laser-pump, positron-probe technique has been developed for measuring the dynamics of laser-induced paramagnetic centers in porous materials. The basis of the technique is the fact that the annihilation rate of ortho-positronium may increase in the presence of unpaired spins. By using an intense... (Read more)

Cathodoluminescence and photoluminescence spectroscopies have been performed on hexagonal boron nitride powders. The combination of these techniques allows us to analyze the two observed luminescence bands. A deep-level UV emission at about 4 eV is attributed to defects or impurities, and a... (Read more)

The annealing of damage generated by low-energy ion implantation in polycrystalline silicon (poly-Si) and amorphous silicon (a-Si) is compared. The rate of heat release between implantation temperature and 350–500 °C for Si implanted in both materials and for different ions implanted in... (Read more)

The absorption and emission spectra of silicon nanocrystals up to 1 nm diameter have been calculated within a first-principles framework. Our calculations include geometry optimization and the many-body effects induced by the creation of an electron-hole pair. Starting from hydrogenated silicon... (Read more)

Contrary to ordinary solids, which are normally known to harden by compression, the compressibility of SiO₂ (silica) glass has a maximum at about 2–4 GPa and its mechanical strength shows a minimum around 10 GPa. At this pressure, the compression of silica glass undergoes a change... (Read more)

First-principles plane-wave calculations were performed for hydroxyapatite (HAp) in order to investigate the electronic structure and vacancy formation mechanisms. The HAp unit cell contains PO₄ tetrahedra and OH groups formed by covalent P-O and H-O bonds. Ca ions play a role for... (Read more)

We report the production and characterization of a form of amorphous carbon with sp-sp² hybridization (atomic fraction of sp hybridized species 20%) where the predominant sp bonding appears to be (=C=C=)_n cumulene.... (Read more)

Fluorine (F) passivation in poly-Si/TaN/HfO₂/p-Si gate stacks through gate ion implantation has been studied. It has been found that when the TaN thickness was less than 15 nm, the mobility and subthreshold swing improved significantly in HfO₂ n-channel... (Read more)

HfO₂ films were grown by atomic layer deposition using two different precursor chemistries—HfCl₄ and tetrakis(diethylamido)hafnium (TDEAH) with H₂O as the oxidant. Electrical measurements on capacitor structures fabricated using the films showed a 0.4 V... (Read more)

Electron spin resonance analysis of (100)Si/LaAlO₃ structures reveals the absence of a Si/SiO₂-type interface in terms of archetypal Si-dangling bond-type Si/SiO₂ interface defects (P_b0,P_b1). With no... (Read more)

The effects of HfSiO nitridation on charge trapping and long-term dielectric reliability are investigated. A comparison between decoupled plasma nitridation, annealing in NH₃, and no nitridation is made. It was found that thinner HfSiO layers show less trapped charge. Decoupled plasma... (Read more)

Low pressure chemical vapor deposition of Si₃N₄ on oxidized Si (111) surfaces causes a change in the properties of the dominant interface defect, the P_b center, observed by electron paramagnetic resonance. The change in the signature of the... (Read more)

Fe-doped HfO₂ thin films are room temperature ferromagnetic. In comparison with results of the undoped HfO₂ films, it seems that the Fe doping is not the main cause for the ferromagnetism but only acts as a catalyst. Experimental results of oxygen annealing and vacuum heat... (Read more)

High-angle annular dark-field imaging in scanning transmission electron microscopy and x-ray photoelectron spectroscopy were used to investigate thermal SiO₂ layers doped with Hf by ion implantation. Hf was mobile under the focused electron beam in the as-implanted samples. After... (Read more)

Hydrogenated amorphous silicon (a-Si:H) films prepared using a molecular beam deposition (MBD) method show an unusually sharp, narrow infrared absorption peak at 2080–2090 cm^–1, which is thought to result from surface SiH species in the a-Si:H. The sharp, narrow... (Read more)

We have investigated the interface states in HfO₂/SiO₂/Si(100) systems that were prepared by using the in situ pulsed laser deposition technique. X-ray photoelectron spectroscopy data revealed that when the HfO₂ film thickness exceeds 11 Å, the film... (Read more)

Two occupied native defect bands are experimentally detected in pure HfO₂. The density of states of band one in the middle of the band gap reduces drastically with the Al addition, while that of band two slightly above the valence-band maximum remains rather unaffected. We attribute the... (Read more)

The effects of nitridation on open volumes in thin HfSiO_x films fabricated by metal-organic chemical vapor deposition were studied using monoenergetic positron beams. It was found that positrons were annihilated from the trapped state by open volumes that exist intrinsically in... (Read more)

The structure of the interface between SiO₂ and Si(100) is investigated using the replica-exchange method driven by classical molecular dynamics simulations based on ab initio-derived interatomic potentials. Abrupt interfaces are shown to be unstable, whereas a substoichiometric... (Read more)

The impact of TiN deposition on thin HfO₂ films formed on Si substrates was studied using x-ray photoelectron spectroscopy and a monoenergetic positron beam. For the predeposition sample, the positrons implanted into Si were found to diffuse toward the HfO₂/Si interface under... (Read more)

To determine if the only source of optical absorption between 5.8 and 5.9 eV is the E center (absorbing at 5.85 eV) two separate suites of type III silica samples were implanted, one with Si and one with O. Several ion energies were used for implantation to produce layers 600 and... (Read more)

Photobleaching of self-trapped holes (STH) in low temperature UV-irradiated silica glass has been investigated by the electron spin resonance method. The bleaching time dependence of the decay of two kinds of STH, STH₁, and STH₂, could be well fitted by the stretched... (Read more)

Hydrogenated amorphous silicon carbide (a-SiC:H) films have been deposited using magnetron sputtering technique. An integrated investigation of the effect of vacuum annealing temperature on photoluminescence properties and paramagnetic defects and its correlation with structural... (Read more)

While it is known that F modifies dopant diffusion in crystalline Si, the physical mechanisms behind this process are still unclear. In this work we report experimental studies about the F control of the point defect density in preamorphized Si layers. These studies put the basis for the... (Read more)

Oxygen bubble formation and evolution under a 300 keV electron beam are analyzed in a Li borosilicate glass under different irradiation conditions: temperature, flux, and dose. Oxygen bubbles are observed to form in a delimited flux and temperature region with a threshold requirement. This region... (Read more)

The parametrization of our recently proposed model of the Staebler-Wronski effect (SWE) is improved, which leads to an even better agreement with the experimental photoconductivity of light-soaked a-Si:H. The numerical solution of the essential equation exhibits well the typical SWE behavior,... (Read more)

The impact of nitridation on open volumes in thin HfSiO_x films fabricated on Si substrates by atomic layer deposition was studied using monoenergetic positron beams. For HfSiO_x, positrons were found to annihilate from the trapped state due to open volumes which... (Read more)

ZnO–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)

Molecular dynamics simulations of collision cascades were performed in three spinel oxides with varying inversion, namely normal magnesium aluminate, MgAl₂O₄, half-inverse magnesium gallate, MgGa₂O₄, and inverse magnesium indate,... (Read more)

We present a detailed analysis of the fundamental atomic-scale processes that determine the surface smoothness of hydrogenated amorphous silicon (a-Si:H) thin films. The analysis is based on a synergistic combination of molecular-dynamics (MD) simulations of radical precursor migration on surfaces... (Read more)

We present a model of amorphous silicon generated by extensive annealing of a continuous random network structure using a molecular dynamics simulation with forces computed by a tight-binding total energy method. We also produce a refined model by relaxing the annealed model using density functional... (Read more)

Nuclear quadrupole resonance (NQR) experiments were performed on glassy As_xSe_1−x to study the local structural order. The bonding in As_xSe_1−x is governed by preferential bonding (chemical ordering) between arsenic... (Read more)

We have irradiated Li₂NH powder with MeV electrons at room temperature and investigated the introduced defects with electron spin resonance. Conduction electron spin resonance indicates the presence of nanosize metallic Li colloids seen as a Lorentzian line with a g=2.0023 and a... (Read more)

We have used molecular dynamics simulation techniques to study the generation of damage in Si within the low-energy deposition regime. We have demonstrated that energy transfers below the displacement threshold can produce a significant amount of damage, usually neglected in traditional radiation... (Read more)

We report on a first-principles investigation of the structural and vibrational properties of vitreous germania (v-GeO₂). Our work focuses on a periodic model structure of 168 atoms, but three smaller models are also studied for comparison. We first carry out a detailed structural... (Read more)

We investigate the hole trapping process of a neutral oxygen vacancy in amorphous silicon dioxide (a-SiO₂) using cluster calculations based on the density functional theory (DFT) method. We show that trapping a hole at a neutral oxygen vacancy leads to the formation of several... (Read more)

Structural aspects of clustering of rare earth ions in oxide glasses have been studied for the last several years in relation to their applications in photonics. However, the mechanism of homogenization of the spatial distribution of rare earth ions by codoping, typically with Al or P, is still not... (Read more)

We use accurate first-principles methods to study the network dynamics of hydrogenated amorphous silicon, including the motion of hydrogen. In addition to studies of atomic dynamics in the electronic ground state, we also adopt a simple procedure to track the H dynamics in light-excited states.... (Read more)

Using ab initio calculations on clusters, we have identified a new reaction path between the dicoordinated silicon atom defect and the paramagnetic Egamma^[prime]" align="middle"> center in amorphous silica. Under ionizing irradiation, the dicoordinated silicon atom... (Read more)

The effects of isochronal thermal treatments on three -irradiation-induced point defects, named the E, ODC(II), and H(I) centers, are investigated in various types of commercial silica (a-SiO₂). ODC(II) is investigated by means of photoluminescence spectroscopy,... (Read more)

The structure of the SiO₂/4H-SiC interface produced by dry oxidation has been studied using positron annihilation spectroscopy using energy-variable slow positron beams. Based on the Doppler broadening shape and wing parameter (S-W) correlation, the interface layer was... (Read more)

We study proton diffusion in amorphous SiO₂ from the atomic scale to the long-range percolative regime. Ab initio molecular dynamics suggest that the dominant atomic process consists in cross-ring interoxygen hopping assisted by network vibrations. A statistical analysis accounting... (Read more)

We report a study by electron paramagnetic resonance on the E_α point defect in amorphous silicon dioxide (a-SiO₂). Our experiments were performed on γ-ray irradiated oxygen-deficient materials and pointed out that the ²⁹Si... (Read more)

Atomic structure and structural stability of neutral oxygen vacancies on amorphous silica are investigated using combined Monte Carlo and density functional calculations. We find that, unlike their bulk counterparts, the Si-Si dimer configuration of surface oxygen vacancies is likely to be unstable... (Read more)

By analyzing atomic force microscopy images, we derive a continuum equation that quantitatively explains the roughening at the Si(001)-SiO₂ interface during thermal oxidation at the temperature at 1200 °C in an Ar atmosphere containing a small fraction of O₂. We also show... (Read more)

Zn2SiO4: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)

Silicon oxynitride films were deposited using a plasma-enhanced chemical vapor deposition process. The bond configurations of the constituent atoms in the deposited film were analyzed using x-ray photoelectron spectroscopy. Analysis of the Si 2p spectra showed the presence of... (Read more)

We report on the use of the LaAlO₃ (LAO) high-k dielectric as a tunnel barrier in magnetic tunnel junctions. From tunnel magnetoresistance (TMR) measurements on epitaxial La_2/3Sr_1/3MnO₃/LAO/La_2/3Sr_1/3MnO₃ junctions,... (Read more)

The electrical behavior of high-permittivity (high-k) hafnium titanium silicate (Hf_xTi_ySi_zO) layers with different Hf:Ti ratios in the films is investigated. The films were deposited by metal-organic chemical-vapor deposition using a... (Read more)

Differential 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)

Electron 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)

We 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)

Aerosol-assisted vapor phase synthesis aimed at preparation of magnetic semiconductor nanopowders of Ga1−xMnxN is carried out both from aqueous and methanol solution mixtures of gallium nitrate and manganese (II) nitrate. After an additional pyrolysis at 1000 °C under an ammonia flow,... (Read more)

Freeze-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)

Using constrained ab initio molecular dynamics, we investigate the reaction of the O₂ molecule at the Si(100)–SiO₂ interface during Si oxidation. The reaction proceeds sequentially through the incorporation of the O₂ molecule in a Si-Si bond and the... (Read more)

The mechanism of hydrogen release from the anode Si/SiO₂ interface that triggers defect generation and finally the dielectric breakdown of the oxide in metal-oxide-semiconductor structures is investigated. Extensive experimental charge-to-breakdown statistics are used to derive the defect... (Read more)

We observed two paramagnetic defects in thin films of HfO₂ on silicon with electron spin resonance. Both appear after photoinjecting electrons into the dielectric. Strong spectroscopic evidence links one spectrum to an O2^-" align="middle"> defect. A second spectrum is... (Read more)

Tungsten 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)

ZnO 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)

We report electron spin resonance (ESR) observation of interface defects at the HfO₂/(111)Si boundary for HfO₂ films deposited via atomic layer chemical vapor deposition using Hf(NO₃)₄ as a precursor. We observe several signals, dominated by one due to a... (Read more)

The structural degradation of thermal SiO₂ on (100)Si under isochronal vacuum annealing in the range T_an = 950 °C–1250 °C was monitored by electron spin resonance (ESR) in terms of point defect creation, including... (Read more)

Optical injection of electron-hole pairs in 3–5 nm thick layers of SiO₂, Al₂O₃, ZrO₂ and their stacks on (100)Si is found to result in positive oxide charging, suggesting trapping of holes. In thin layers of the high-permittivity metal oxides... (Read more)

In 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)

We 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)

The diffusion and reactions of hydrogenous species generated by single-pulsed F₂ laser photolysis of SiO-H bond in SiO₂ glass were studied in situ between 10 and 330 K. Experimental evidence indicates that atomic hydrogen (H⁰) becomes mobile even at temperatures as... (Read more)

We propose a network rebonding model for light-induced metastability in amorphous silicon, involving bonding rearrangements of silicon and hydrogen atoms. Nonradiative recombination breaks weak silicon bonds and generates dangling bond?floating bond pairs, with very low activation energies. The... (Read more)

Some 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)

We 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)

Experimental studies of size-related effects in silicon nanocrystals are reported. We present investigations carried out on nanocrystals prepared from single-crystal Si:P wafer by ball milling. The average final grain dimension varied depending on the way of preparation in the range between 70 and... (Read more)

We present theoretical evidence that the paramagnetic E^? defect centers in amorphous silicon dioxide ( a-SiO₂) do not have the same microscopic structures as those well-defined in the corresponding crystalline counterparts such as ?-quartz. We then present alternative models of... (Read more)

We provide a new model of the peroxy-radical defect in amorphous silica on the basis of quantum-chemical calculations applied to clusters of atoms to model the defect. In this model, the ²⁹Si hyperfine splittings of the peroxy radical arise from a single silicon, in agreement with the... (Read more)

We show that Cat-CVD silicon nitride films contain more than 1019 cm−3 nitrogen-bonded Si dangling bonds, similarly to the case for conventional CVD films. However, the charge-trapping behavior of the Cat-CVD films is found to be quite different, in spite of the same origin for the dominant... (Read more)

Electron paramagnetic resonance has been used to study the influence of thermal treatments on defect evolution in helium-implanted Czochralski single-crystal silicon. It is shown that the thermal treatment induces helium migration and capturing by vacancy clusters that transform into pressurized... (Read more)

Using a first-principles approach, we characterize dangling bond defects at Si-SiO₂ interfaces by calculating hyperfine parameters for several relaxed structures. Interface models, in which defect Si atoms remain close to crystalline sites of the substrate upon relaxation, successfully... (Read more)

The interaction of atomic hydrogen with a-Si:H films was studied by means of in situ ESR during H plasma treatment. H diffuses into the a-Si:H film and creates additional Si dangling bonds (∼10¹³ cm ^-2). We observed a high diffusion coefficient (>10^-10  cm... (Read more)

The 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)

The 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)

ZnO 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)

Spin-dependent transport processes in hydrogenated amorphous silicon (a-Si:H) solar cells at high frequencies are studied with capacitively-detected magnetic resonance (CDMR). A resonant increase of the capacitance at room temperature is found with a g-factor of 2.0055, characteristic for the spin-dependent trapping of electrons at neutral dangling bonds. It is shown that with the help of spin-dependent capacitance measurements quantitative information on the defect density in the device can be obtained, a particular advantage over conventional electrically detected magnetic resonance (EDMR) where resonant changes of the dc conductivity are measured. (Read more)

Photoluminescence (PL) properties of SiNx (0.51<x<1.3) films are studied. A visible luminescence near the UV region is observed and the PL intensity and peak positions are found to be governed by the excess silicon composition. A large scale potential fluctuation due to the spatial... (Read more)

It 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)

The spectroscopic properties, structure and interconversions of optically active oxygen-deficiency-related point defects in vitreous silica are reviewed. These defects, the E′-centers (oxygen vacancies with a trapped hole or 3-fold-coordinated silicons), different variants of diamagnetic... (Read more)

Electron paramagnetic resonance (EPR) measurements of Si/SiO₂ systems began over 30 years ago. Most EPR studies of Si/SiO₂ systems have dealt with two families of defects: P_b centers and E centers. Several variants from each group have... (Read more)

Four sets of ESR doublets with splittings of 9, 23, 26 or 44 mT were observed in dry a-SiO2 (Type IV, OH concentrations1017 cm−3) implanted with 29Si+ to a fluence of 6×1016 cm−2 at 160 keV. These doublets were attributed to the hyperfine structures due to a 29Si nucleus of... (Read more)

The requirement for increasingly thin (<50 Å) insulating oxide layers in silicon-based electronic devices highlights the importance of characterizing the Si–SiO₂ interface structure at the atomic scale. Such a characterization relies to a large extent on an understanding of the atomic-scale mechanisms that govern the oxidation process. The widely used Deal–Grove model invokes a two-step process in which oxygen first diffuses through the amorphous oxide network before attacking the silicon substrate, resulting in the formation of new oxide at the buried interface¹. But it remains unclear how such a process can yield the observed near-perfect interface^{2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12}. Here we use first-principles molecular dynamics^{13, 14, 15} to generate a model interface structure by simulating the oxidation of three silicon layers. The resulting structure reveals an unexpected excess of silicon atoms at the interface, yet shows no bonding defects. Changes in the bonding network near the interface occur during the simulation via transient exchange events wherein oxygen atoms are momentarily bonded to three silicon atoms — this mechanism enables the interface to evolve without leaving dangling bonds. (Read more)

Intrinsic defect formation in amorphous (a-) SiO2 by ion implantation was examined with emphasis upon electronic excitation effects and chemical reaction effects. 10 MeV proton beam and boron beam irradiated silica platelets to examine electronic excitation effects and chemical reaction effects. In... (Read more)

Concentrations of defects in amorphous SiO₂ created by implantation of 10 MeV protons were examined. The depth profile of Si-Si bonds, E^? centers, or peroxy radicals (PORs) was close to that of electronic energy loss. Interstitial O₂ molecules were identified and... (Read more)

In situ electron-spin-resonance (ESR) measurements of film growth of hydrogenated amorphous silicon (a-Si:H) using a remote hydrogen plasma technique have been performed. The Si dangling-bond signal in a-Si:H during and after deposition has been detected, in addition to the... (Read more)

The properties of silicon nitride (SiN_x) films produced by the catalytic chemical vapor deposition (cat-CVD) method are extensively studied for device application. In the cat-CVD method, the deposition gases such as a silane (SiH₄) and ammonia (NH₃) gas... (Read more)

By 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)

We 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)

Electron 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)

Electron paramagnetic resonance spectra were measured on SiO2 glasses implanted with Si ions to a fluence of 6 × 1016 cm−2 at an acceleration voltage of 160 kV. Three sets of doublets with different separation were observed in Si29-implanted substrates and were ascribed to primary... (Read more)

Three varieties of E′ centers with a spin state, S = 1/2, and with a G-tensor, Gx Gy 2.0003, Gz 2.0018, were identified in the early reports on paramagnetic states in irradiated α-quartz. The atomic structure of two of these had an hydrogen ion (proton) in nearby sites and hence... (Read more)