Formation and Passivation of New Paramagnetic Defects Associated With Thermal Oxides On Silicon

1987 ◽  
Vol 105 ◽  
Author(s):  
Keith L. Brower
Keyword(s):  
Oxidation Process ◽  
Resonance Spectrum ◽  
The Other ◽  
Paramagnetic Resonance ◽  
Thermal Oxide ◽  
Impurity Contamination ◽  
Spin Resonance ◽  
G Value ◽  
Electron Paramagnetic ◽  
Grown Thermal Oxide

AbstractA new spin resonance spectrum has been observed with electron paramagnetic resonance in thermal oxides grown on (111) silicon. Our analysis indicates that this new spectrum consists of two isotropic resonances. One resonance has a g-value of 2.0026 and a linewidth (FWHM) of 1.2 G (labeled SL8); the other resonance has a g-value of 2.0029 and a linewidth (FWHM) of 5 G (labeled SL9). These spectra might be due to impurity contamination resulting from the oxidation process and associated with defects at interior surfaces. The SL8 resonance in particular appears to be located within the as-grown thermal oxide. The effects of 60Co gamma irradiation and annealing in either hydrogen or ammonia on these spectra are also presented in this paper.

scholarly journals Simulation of the electron-paramagnetic-resonance spectrum of the iron-protein of nitrogenase. A prediction of the existence of a second paramagnetic centre

1978 ◽  
Vol 175 (3) ◽  
pp. 955-957 ◽  
Author(s):  
D J Lowe
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Electron Paramagnetic Resonance Spectrum ◽  
Complex Formation ◽  
Resonance Spectrum ◽  
The Other ◽  
Paramagnetic Centre ◽  
Paramagnetic Resonance ◽  
Iron Protein ◽  
Integrated Intensities ◽  
Electron Paramagnetic

The e.p.r. spectra of the Fe-proteins of nitrogenase from all sources studied have unusual features in that they have very anisotropic linewidths and low integrated intensities. These characteristics can be explained by assuming that one of the two electrons accepted by these proteins is located at a rapidly relaxing paramagnetic centre that is unobservable by e.p.r., but causes anisotropic broadening of the e.p.r. signal of the other electron. Complex-formation between Fe-proteins and MgATP is described in terms of a 50-60 degrees rotation of the e.p.r.-observable centre.

Temperature Dependent Line-Shape of the Silicon Dangling Bond EPR-Resonance in Polycrystalline Silicon

1996 ◽  
Vol 452 ◽  
Author(s):  
N. H. Nickel ◽  
E. A. Schiff
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Polycrystalline Silicon ◽  
Room Temperature ◽  
Dangling Bond ◽  
Temperature Dependent ◽  
Paramagnetic Resonance ◽  
Temperature Electron ◽  
Motional Narrowing ◽  
G Value ◽  
Electron Paramagnetic

AbstractThe temperature dependence of the silicon dangling-bond resonance in polycrystalline (poly-Si) and amorphous silicon (a-Si:H) was measured. At room temperature, electron paramagnetic resonance (EPR) measurements reveal an isotropie g-value of 2.0055 and a line width of 6.5 and 6.1 G for Si dangling-bonds in a-Si:H and poly-Si, respectively. In both materials spin density and g-value are independent of temperature. While in a-Si:H the width of the resonance did not change with temperature, poly-Si exhibits a remarkable T dependence of ΔHpp. In unpassivated poly-Si a pronounced decrease of ΔHpp is observed for temperatures above 300 K. At 384 K ΔHpp reaches a minimum of 5.1 G, then increases to 6.1 G at 460 K, and eventually decreases to 4.6 G at 530 K. In hydrogenated poly-Si ΔHpp decreases monotonically above 425 K. The decrease of ΔHpp is attributed to electron hopping causing motional narrowing. An average hopping distance of 15 and 17.5 Å was estimated for unhydrogenated and H passivated poly-Si, respectively.

Gas-phase electron paramagnetic resonance spectrum and dipole moment of NF( 1 ∆)

1973 ◽  
Vol 332 (1590) ◽  
pp. 355-363 ◽  
Keyword(s):  
Dipole Moment ◽  
Gas Phase ◽  
Resonance Spectrum ◽  
Rotational Level ◽  
Quadrupole Coupling Constant ◽  
Rotational Constant ◽  
Coupling Constants ◽  
Paramagnetic Resonance ◽  
Quadrupole Coupling ◽  
Electron Paramagnetic

The gas-phase paramagnetic resonance spectrum of NF in the J = 2 rotational level of the 1 ∆ state has been studied, and the dipole moment in this state is found to be 0.37 ± 0.60D. The rotational constant previously determined from the electronic spectrum is shown to be consistent with the electron resonance results, and the 14 N quadrupole coupling constant e 2 qQ is 4.1 ± 0.2 MHz. The hyperfine coupling constants of the 14 N and 19 F nuclei are + 109.92 ± 0.14 and +758.06 ± 0.23 MHz respectively.

scholarly journals Copper Complexes of Benzoylacetone Bis-Thiosemicarbazones: Metal and Ligand Based Redox Reactivity

2021 ◽  
Vol 74 (1) ◽  
pp. 34 ◽  
Author(s):  
Jessica K. Bilyj ◽  
Jeffrey R. Harmer ◽  
Paul V. Bernhardt
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Cyclic Voltammetry ◽  
Copper Complexes ◽  
Atmospheric Oxygen ◽  
The Other ◽  
Oxidation Reactions ◽  
Paramagnetic Resonance ◽  
Time Resolved ◽  
Vis Spectroscopy ◽  
Electron Paramagnetic

Bis-thiosemicarbazones derived from the β-diketone benzoylacetone (H3banR, R=Me, Et, Ph) are potentially tetradentate N2S2 ligands whose coordination chemistry with copper is reported. In the absence of oxygen and in the presence of base they form anionic CuII complexes of the fully deprotonated ligands [CuII(banR)]–. Upon exposure to atmospheric oxygen they undergo a complex series of reactions leading to two types of products; one a ligand oxidised ketone complex [CuII(banRO)] and the other an unprecedented dimeric di-CuIII complex [(CuIII(banR))2] depending on the R substituent. Time-resolved UV-vis spectroscopy, cyclic voltammetry, spectroelectrochemistry, and electron paramagnetic resonance (EPR) spectroscopy have been used to identify intermediates on the way to stable products formed under both anaerobic and aerobic conditions. It is found that both ligand-centred and Cu-centred oxidation reactions are occurring in parallel leading to this unusually complicated mixture of products.

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