Experimental alternating-current conductivity data were analyzed for glassy materials (SiO2-35Li2O-3Al2O3-P2O5 and M2O·3B2O3; with M = Li, Na, K or Rb) and crystalline ionic conductors (Li0.18La0.61TiO3 and ZrO2-16Y2O3) at temperatures ranging from 400 to 8K. At sufficiently low temperatures, the dielectric loss was found to be almost independent of frequency, and this nearly constant loss always exhibited a weak temperature dependence. Good agreement was found between experimental data and the theoretical predictions of a new scheme, for the nearly constant loss, which was based upon a coupling model.

Temperature Dependence of the Near Constant Loss in Ionic Conductors - a Coupling Model Approach. A.Rivera, J.Santamaría, C.León, K.L.Ngai: Journal of Physics - Condensed Matter, 2003, 15[16], S1633-42