Endor Spectroscopy on Deep Level Defects in Gaas

1987 ◽  
Vol 104 ◽  
Author(s):  
J.-M. Spaeth ◽  
A. Gorger ◽  
D. M. Hofmann ◽  
B. K. Meyer
Keyword(s):  
Deep Level ◽  
Double Resonance ◽  
Thermal Conversion ◽  
Electron Nuclear Double Resonance ◽  
Endor Spectroscopy ◽  
Spin Resonance ◽  
Pair Defect ◽  
Theoretical Predictions ◽  
Optically Detected ◽  
First Time

ABSTRACTWith optically detected electron spin resonance (ODESR) and electron nuclear double resonance (ODENDOR) the following deep level defects in s.i. LEC-grown GaAs were investigated: EL2 defects in undoped GaAs and VGa2+ and VGa3+ defects in V-doped GaAs. This paper summarizes the major results: (i) the double donor defect EL2 in an (AsGa-Asi+) pair defect, which is distributed rather homogeneously across an as-grown wafer. After inverted thermal conversion treatment it is destroyed, and 3 new paramagnetic defects appear. EL2 is recovered after annealing at ca. 800 °C, while the 3 new defects disappear. (ii) A new ESR spectrum due to VGa2+ was measured. It is shown for the first time for a 3dn impurity in semiconductors that VGa3+(3d3)is in a low spin state (S = 1/2) in accordance with recent theoretical predictions. A deep level defect at Ev + (0.2–0.4) eV is discovered, which is probably the defect needed for explaining the s.i. properties of V-doped GaAs.

Magnetic Resonance of Oxygen-Related Defects in Silicon

1985 ◽  
Vol 59 ◽  
Author(s):  
J. Michel ◽  
J. R. Niklas ◽  
J.-M. Spaeth
Keyword(s):  
Effective Mass ◽  
Hyperfine Interactions ◽  
Double Resonance ◽  
Uniaxial Stress ◽  
Esr Spectra ◽  
Electron Nuclear Double Resonance ◽  
The Core ◽  
Spin Resonance ◽  
Unpaired Spin ◽  
First Time

ABSTRACTThe electron spin resonance (ESR) of a number of vacancy-oxygen complexes created in electron irradiated Si containing oxygen is briefly reviewed. In these centers the unpaired spin density is highly localised (50–70%) on two Si sites within the complex. The ESR spectra of several paramagnetic thermal donors (TD+) formed by annealing oxygen-rich Si at 450 °C for one to several hundred hours are reviewed as well as recent experiments under uniaxial stress from which for the ground state a 2 valley effective mass-like wavefunction was derived. Results of electron nuclear double resonance (ENDOR) experiments on the TD+ ESR line “NL8” are presented for the first time. They reveal that all TD's identified in IR-spectroscopy are superimposed in the NL8 ESR line and that upon growth of the TD the structure of the core and the symmetry of the TD's is not changed. The hyperfine interactions with up to 7 shells of Si nuclei of 5 TD+'s were determined. Their size and tensor orientations are consistent with the two-valley effective mass-like wavefunction. 4 TD's identified in ENDOR could be correlated with IR-bands from growth kinetics. Although the ENDOR experiments so far do not yet lead to a detailed TD model, the model possibilities are narrowed down considerably by these results. The core must consist of nuclei with very low magnetic abundancy. It is tentatively suggested, that the core contains an O2 molecule.

Electron Spin Resonance and Electron Nuclear Double Resonance Spectroscopy: Application to the Study of Trapped Electrons

1980 ◽  
Vol 34 (3) ◽  
pp. 293-295 ◽  
Author(s):  
Harold C. Box ◽  
Harold G. Freund
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Double Resonance ◽  
Resonance Spectroscopy ◽  
Electron Nuclear Double Resonance ◽  
Trapped Electrons ◽  
V Band ◽  
Endor Spectroscopy ◽  
Hydroxy Proton ◽  
Spin Resonance

V band electron spin resonance-ENDOR spectroscopy has been applied to the study of “trapped” electrons in single crystals of polyhydroxy and carbohydrate compounds X-irradiated at low temperature. Evidence is presented from ENDOR measurements of hydroxy proton couplings that electrons are stabilized at intermolecular sites. The electron can be stabilized in the dipole fields of two or three hydroxy groups.

Optically detected electron nuclear double resonance on the residual donor in GaN

1997 ◽  
Vol 43 (1-3) ◽  
pp. 181-184
Author(s):  
F.K. Koschnick ◽  
K. Michael ◽  
J.-M. Spaeth ◽  
B. Beaumont ◽  
P. Gibart
Keyword(s):  
Double Resonance ◽  
Electron Nuclear Double Resonance ◽  
Optically Detected

scholarly journals Electron nuclear double-resonance (ENDOR) spectroscopy of amine oxidase from pig plasma

1986 ◽  
Vol 237 (2) ◽  
pp. 609-612 ◽  
Author(s):  
G J Baker ◽  
P F Knowles ◽  
K B Pandeya ◽  
J B Rayner
Keyword(s):  
Hyperfine Coupling ◽  
Amine Oxidase ◽  
Double Resonance ◽  
Spectroscopic Studies ◽  
Water Molecules ◽  
Electron Nuclear Double Resonance ◽  
Endor Spectroscopy ◽  
Amino Acid Histidine ◽  
Plasma Amine Oxidase ◽  
Hyperfine Couplings

Electron nuclear double-resonance (‘ENDOR’) spectroscopic studies on pig plasma amine oxidase have been carried out at 15 K. Deuterium-exchange studies show the presence of two sets of exchangeable protons, probably from two water molecules; from the magnitude of their hyperfine couplings, one is assigned to be equatorially, and the other axially, co-ordinated. Only one 14N hyperfine coupling is observed, suggesting that the bonding of all amino acid (histidine) or organic cofactor ligands is similar. Upon addition of azide, a further hyperfine coupling to nitrogen is observed which is smaller than that observed for the native enzyme; the hyperfine couplings to the remaining nitrogens are slightly altered.

Using Hyperfine Interaction for the Structural Characterization of Amorphous Silicon

1986 ◽  
Vol 69 ◽  
Author(s):  
Martin Stutzmann ◽  
David K. Biegelsen
Keyword(s):  
Hyperfine Interaction ◽  
Amorphous Silicon ◽  
Dipolar Coupling ◽  
Double Resonance ◽  
Nuclear Spins ◽  
Electron Nuclear Double Resonance ◽  
Resonance Frequencies ◽  
Spin Resonance ◽  
Nuclear Spin System

AbstractThe hyperfine interaction between electronic and nuclear spins in hydrogenated amorphous silicon has been observed for the various paramagnetic defects in this material by electron spin resonance (ESR) and electron nuclear double resonance (ENDOR). The large hyperfine interaction between dangling bonds and 29Si as well as between donor electrons and 31p or 75 As nuclei can be resolved in ESR and provides direct information about the structure of the underlying electronic states. The smaller dipolar coupling of all paramagnetic states to more distant nuclei leads to an ENDOR response near the free nuclear resonance frequencies, which can be used to study the coupling of the electronic and nuclear spin system to the lattice phonons and to each other.

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