Neutron spin echo study of spin glass dynamics (invited)

Abstract

The neutron spin echo technique allows us to obtain direct, model independent information on spin relaxation in the time domain of 3×10−12 to 3×10−9 sec. The experimental results on a variety of spin glass samples reveal a number of common characteristic features. Namely (a) the relaxation kinetics correspond to a broad distribution of relaxation times; (b) the slowing down of the relaxation can be described by an Arrhenius law above the freezing temperature, but not around and below; (c) the absence of momentum dependence in the relaxation dynamics indicates that nonexchange type interactions play a fundamental role in this dynamics.