Electron paramagnetic resonance, electron spin echo modulation and electron nuclear double resonance studies on the photoionization of N-alkylphenothiazines in cetyltrimethylammonium bromide–alcohol reverse micelles. Effects of alkyl chain length of alkylphenothiazines, reverse micellar water pool size and cosurfactant alcohol

1993 ◽  
Vol 89 (9) ◽  
pp. 1377-1382
Author(s):  
Young Soo Kang ◽  
Larry Kevan
Keyword(s):  
Reverse Micelles ◽  
Cetyltrimethylammonium Bromide ◽  
Spin Echo ◽  
Double Resonance ◽  
Electron Spin Echo ◽  
Electron Nuclear Double Resonance ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic ◽  
Electron Spin Echo Modulation ◽  
Resonance Electron

EPR, ESE and Pulsed ENDOR Study of Nitrogen Related Centers in 4H-SiC Wafers Grown by Different Technologies

2007 ◽  
Vol 556-557 ◽  
pp. 355-358 ◽  
Author(s):  
Ekaterina N. Kalabukhova ◽  
S.N. Lukin ◽  
D.V. Savchenko ◽  
W.C. Mitchel ◽  
Siegmund Greulich-Weber ◽  
...  
Keyword(s):  
Lattice Site ◽  
Spin Echo ◽  
Double Resonance ◽  
Hexagonal Lattice ◽  
Electron Spin Echo ◽  
Epr Spectrum ◽  
Electron Nuclear Double Resonance ◽  
Paramagnetic Resonance ◽  
Hall Effect Measurements ◽  
Electron Paramagnetic

D-band electron paramagnetic resonance (EPR) measurements as well as X and Q-band field-swept Electron Spin Echo (ESE) and pulsed Electron Nuclear Double Resonance (ENDOR) studies were performed on a series of n-type 4H-SiC wafers grown by different techniques including sublimation sandwich method (SSM), physical vapor transport (PVT) and modified Lely method. Depending on the C/Si ratio and the growth temperature the n-type 4H-SiC wafers revealed, besides a triplet due to nitrogen residing on the cubic site (Nc), two nitrogen (N) related EPR spectra with g||=2.0055, g⊥=2.0010 and g||=2.0063, g⊥=2.0005 with different intensities. In the samples with low C/Si ratio the EPR spectrum with g|| =2.0055, g⊥=2.0010 consists of a triplet with low intensity which is tentatively explained as a N-related complex, while in the samples with high C/Si ratio the triplet is transformed into one structureless line of high intensity, which is explained as being due to an exchange interaction between N donors. In the samples grown at low temperature with enhanced carbon concentration the EPR line with g||=2.0063, g⊥=2.0005 and a small hyperfine (hf) interaction dominates the EPR spectrum. It is attributed to N on the hexagonal lattice site. The interpretation of the EPR data is supported by activation energies and donor concentrations obtained from Hall effect measurements for three donor levels in this series of 4H-SiC samples.

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