ELECTRON SPIN-LATTICE RELAXATION-TIME AND SPECTRAL DIFFUSION IN GAMMA-IRRADIATED L-ALANINE

被引:20
作者
BRUSTOLON, M [1 ]
SEGRE, U [1 ]
机构
[1] UNIV MODENA,DIPARTIMENTO CHIM,I-41100 MODENA,ITALY
关键词
D O I
10.1007/BF03162621
中图分类号
O64 [物理化学(理论化学)、化学物理学]; O56 [分子物理学、原子物理学];
学科分类号
070203 ; 070304 ; 081704 ; 1406 ;
摘要
We performed continuous (CW) wave and pulsed ESR experiments to obtain information on the relaxation behavior of the 1-alanine radical in an irradiated single crystal. The analysis of the CW saturation behavior gives a relaxation time of 2.8 mu s. The echo detected saturation recovery was obtained for a number of different experimental conditions. Tn any case only a portion of the 120 G wide ESR spectrum can be affected by the microwave (MW) pulses, spectral diffusion is active and a multi-exponential decay is therefore obtained. We measured characteristic spectral diffusion times of 1-10 and 20-50 mu s. We found that a long time of about 200 mu s can be measured only by using a train of long selective saturating pulses and short detecting pulses. The stimulated echo decay is bi-exponential, and the characteristic times are very short. A variable temperature investigation in the range 200 to 290 K showed that the decay is governed by the spectral diffusion and by the transverse nuclear spin relaxation time T-2n of the methyl protons.
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页码:405 / 413
页数:9
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