We 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)

Electron paramagnetic resonance and ab initio supercell calculations suggest that the P6/P7 centers, which were previously assigned to the photoexcited triplet states of the carbon vacancy-antisite pairs in the double positive charge state, are related to the triplet ground... (Read more)

The EPR spectra of Fe3+ in high-quality thick freestanding hydride vapor phase grown GaN have been studied in the X- and Q-band. A complex resonance pattern with numerous lines of different intensities provided by three different defects is observed for these nearly stress-free iron-doped samples.... (Read more)

The Ti³⁺ center, based on a regular Ti site perturbed by an oxygen vacancy (V_O), is identified by electron spin resonance (ESR) in textured BaTiO₃ films. The center shows tetragonal symmetry along cubic 100 axes with g-factors: g=1.997,... (Read more)

Combining 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)

We 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)

Electron 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)

Recent 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)

We investigated radiation-induced defects in neutron-irradiated and subsequently annealed 6H-silicon carbide (SiC) with electron paramagnetic resonance (EPR), the magnetic circular dichroism of the absorption (MCDA), and MCDA-detected EPR (MCDA-EPR). In samples annealed beyond the annealing... (Read more)

Formation of intrinsic and impurity defect complexes in hydrogenated monocrystalline silicon is studied. Hydrogen was incorporated into samples by different ways: either by proton implantation at 80 and 300 K, or by annealing at 1250°C for 30–60 min in a sealed quartz ampoule containing... (Read more)

The passivation by hydrogen of selenium double donors in silicon has been investigated by magnetic resonance. Hydrogen was introduced by heat treatment at high temperatures in an atmosphere of water vapor. Two spectra were observed, labeled Si-NL60 and Si-NL61 for further reference, both showing... (Read more)

n- and p-type float-zone silicon containing 10¹⁸-cm^-3 tin were irradiated with 2 MeV electrons to a dose of 10¹⁸ cm^-2 and subsequently examined by electron paramagnetic resonance (EPR). The p-type material yields only the well-known Si-G29 signal due to... (Read more)

An EPR signal observed in carbon-doped float-zone silicon after irradiation with 2-MeV electrons at room temperature has been investigated. It represents a defect with S=1/2, an apparently isotropic g factor (=2.0030), and a complicated hyperfine structure from ²⁹Si nuclei in five shells... (Read more)

Recent deep level transient spectroscopy (DLTS), electron paramagnetic resonance (EPR) and infrared (IR) spectroscopy data on interactions of self-interstitial with carbon, aluminium, oxygen and hydrogen in silicon irradiated by light ions are reviewed. Self-interstitial behaviour in silicon was... (Read more)

Electron-paramagnetic-resonance (EPR) studies in radiation damaged diamond enriched to 5% ¹³C have resulted in the identification of the nearest-neighbor divacancy center. It is the isotopic enrichment, and consequent observation of ¹³C hyperfine lines, that has permitted the... (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)

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)

Electron paramagnetic resonance measurements on float-zone silicon implanted with protons at ?50 K followed by heating to room temperature have revealed two signals S1_a and S1_b belonging to the S1 group of signals. S1_a and S1_b both originate from defects... (Read more)

A high-frequency (95 GHz) and conventional-frequency (9.3 GHz) pulsed electron paramagnetic resonance and electron-nuclear double resonance (ENDOR) study is reported on the deep boron acceptor in 6H-SiC. The results support a model in which the deep boron acceptor consists of a boron on a silicon... (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)

Nitrogen donors in 6H-, 4H- and 3C-SiC were investigated using conventional electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR) and the experimental results are discussed. An attempt is presented to interpret the experimentally found large differences in hyperfine... (Read more)

We report the observation of orthorhombic Au-Li and Pt-Li pairs in Si using EPR and ENDOR techniques and also MCDA spectroscopy. The EPR spectra alone could be mistaken as being due to orthorhombic isolated point defects and ENDOR is required to detect the Li partner of the pair. Comparison of the... (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)

A total of five new electron paramagnetic resonance (EPR) centers are observed in electron-irradiated P-, As-, and Sb-doped silicon. Three are identified as arising from the neutral charge state of the stable configuration and two of the four metastable configurations of an... (Read more)

Direct evidence for the creation of oxygen-vacancy, oxygen-interstitial pairs in SiO₂ glasses by an excitonic mechanism is developed from an electron-spin-resonance study of high-purity fused silicas exposed to highly focused 6.4-eV excimer laser light. (Read more)

By combining several spectroscopic techniques, we have observed a new type of bistable center in electron-irradiated silicon and have identified it as an interstitial-carbon?substitutional-carbon pair. The positive and negative charge states of the defect share a common stable configuration which... (Read more)

At 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)

This paper deals with an electron-paramagnetic-resonance study of the Si-B3 center, which was first reported by Daly. The Si-B3 center is a secondary defect which forms upon annealing between 50 and 175?C in irradiated boron-doped silicon and is stable up to ?500?C. Our studies indicate that the... (Read more)

The Si-P6 spectrum shows an intrinsic tetragonal symmetry with the C₂ axis along ?100? and distortion forces the principal axes of the g tensor to be displaced in the {100} plane. The g tensor previously identified by Jung and Newell was found to be due to the motionally averaged state... (Read more)

EPR studies of silicon irradiated at 20.4 K and 4.2 K by 1.5 MeV and 46 MeV electrons are described. In 46 MeV irradiations the dominant defects formed appear to be divavancies and other multiple defect aggregates which liberate vacancies throughout the anneal to room temperature as they reorder, recombine, etc. For 1.5 MeV irradiations group III atoms play a vital role in p- and n-type materials in trapping interstitials and stabilizing damage. Carbon and oxygen are not effective interstitial traps at these temperatures. Evidence of limited vacancy migration during irradiation is also cited. Two distinct excited configurations of vacancy-oxygen pairs are identified as precursors to A-centre formation in n-type silicon. The kinetics for their conversion to A-centres depends strongly upon the Fermi level as does the isolated vacancy migration energy whhich is measured to be 0.18 ± 0.02 eV for the V^＝ charge state. The vacancy has four charge states, V^＋, V⁰, V^－ and V^＝. Kinetics for hole release from V^＋ reveals an activation barrier of 0.057 eV. The concentration of V^＋ at 20.4 K in boron-doped material indicates the corresponding donor level even closer to the band edge, approximately E_V ＋ 0.039 eV. Jahn-Teller energies for V⁰, V^＋, and V^－ are estimated from stress-alignment studies and confirmed to be large. Kinetics studies for reorientation from one Jahn-Teller distortion to another are also described for each charge state.

An EPR study was made of the divacancy in silicon, produced by 1.5-MeV electron irradiation at room temperature, under illumination with polarized light. A light-induced alignment of divacancies among the various Jahn-Teller distortion directions in the lattice is observed for the singly positively... (Read more)

An EPR spectrum produced in aluminum-doped silicon by 1.5-MeV electron irradiation is described. Labeled Si G9, it is identified as arising from an aluminum-vacancy pair, presumably formed when a mobile lattice vacancy is trapped by substitutional aluminum. The resonance is observed only upon... (Read more)

A study is described of the dependence of the room-temperature production of divacancies and vacancies in silicon upon the energy of the bombarding electrons over the range 0.7-56 MeV. For the divacancy, the Si-G6 electron-paramagnetic-resonance spectrum associated with the singly positively charged... (Read more)

Infrared and electron-spin-resonance measurements on the recovery of silicon irradiated with 1.5-MeV electrons are presented. In the infrared measurements the disappearance of the previously reported 829-cm^-1 (12?) oxygen vibration band is followed, and the appearance and subsequent... (Read more)