Order parameter determination in proton and deuteron glasses via NMR and EPR: the fast and slow motion limits

Abstract

The recently developed dynamic approaches to NMR and EPR lineshapes in proton and deuteron glasses are described and the obtained order parameters are compared with the predictions of the various theoretical models. It is shown that spin-lattice relaxation and magnetization recovery measurements allow for the extension of the NMR technique for order parameter determinations to timescales that are four or five orders of magnitude slower than those that allow for an extraction of order parameters from lineshape measurements. The obtained results show that we deal with a random field smearing of the proton glass transition. The question of the existence of a transition from an ergodic proton glass phase to a non-ergodic proton glass phase is still open.