Structural alpha relaxation in liquid orthoterphenyl is studied by means of coherent neutron time-of-flight and backscattering spectroscopy over a large temperature range. Not only amplitude and relaxation time but also the spectral line shape show a significant variation with wavenumber. As expected from mode coupling theory, these variations are correlated with the static structure factor. Even far above the melting point, alpha relaxation remains non-exponential.
@article{arxiv.cond-mat/9801066,
title = {Wavenumber dependence of structural alpha relaxation in a molecular liquid},
author = {A. Toelle and H. Schober and J. Wuttke and F. Fujara},
journal= {arXiv preprint arXiv:cond-mat/9801066},
year = {2011}
}