Dielectric Relaxation Mechanism for Proton Glass

Abstract

Dielectric relaxation of proton glasses is controlled by 0-H…0 proton intrabond hopping responsible for ‘Takagi’ HPO4 and H3PO4 intrinsic defect diffusion. The diffusion path has a one-dimensional fractal topology. The defects diffuse in a potential which also has a fractal nature, giving a barrier height distribution leading to a wide spread in dielectric relaxation times at low temperature. Expressions for dielectric relaxation and ac susceptibility are derived, and their fit to experimental results is briefly discussed.