The origin of the non-exponential relaxation of silver ions in the crystalline ion conductor Ag7P3S11 is analyzed by comparing appropriate two-time and three-time 109Ag NMR correlation functions. The non-exponentiality is due to a rate distribution, i.e., dynamic heterogeneities, rather than to an intrinsic non-exponentiality. Thus, the data give no evidence for the relevance of correlated back-and-forth jumps on the timescale of the silver relaxation.
@article{arxiv.cond-mat/0310256,
title = {Origin of non-exponential relaxation in a crystalline ionic conductor: a multi-dimensional 109Ag NMR study},
author = {M. Vogel and C. Brinkmann and H. Eckert and A. Heuer},
journal= {arXiv preprint arXiv:cond-mat/0310256},
year = {2009}
}