Towards a better understanding of oxonium motion in crystals conduction in oxides

T1 curves for our oxonium salts have been determined. They are discussed with respect to two hypotheses. In the first, the motion is described by two uncorrelated motions: a reorientation about the main H3O+ axis and random isotropic spherical (or endospehrical) motion of this axis. In the second, a third-order reorientation of an asymmetric potentiel is considered. These two types of motion explain the main characteristics of the T1 curves; they appear to give two extreme descriptions of the true motion in different sites. A more elaborated discussion should take into account a precise description of individual H3O+ environments (sites). (author)