J. Phys. Colloques
Volume 42, Numéro C4, Octobre 1981Proceedings of the Ninth International Conference on Amorphous and Liquid Semiconductors
|Page(s)||C4-835 - C4-838|
J. Phys. Colloques 42 (1981) C4-835-C4-838
TEMPERATURE AND FREQUENCY DEPENDENCES OF NMR SPIN-LATTICE RELAXATION TIME T1 IN a-Si : HK.L. Ngai
Naval Research Laboratory, Washington, D.C. 20375, U.S.A.
Carlos and Taylor have recently reported pulsed 1H NMR measurements on the spin-lattice relaxation time T1 for the hydrogen atoms in glow discharge prepared a-Si : H. They have measured both the magnitude and the temperature and frequency dependences of T1 and observed a number of interesting features. Among these are the presence of an asymmetric minimum in T1 at a temperature Tmin near 40K which is relatively insensitive to frequency ν0 and a strong dependence of T1 on ν0 for T < Tmin which is suppressed for T > Tmin. These features are consistent with a unified and universal model of low frequency fluctuation, dissipation and relaxation properties of condensed matter.