Measurements were made of the diffusion of radioactive 110mAg in polycrystalline Pb(Ni1/3Nb2/3)O3 - 35PbTiO3 - 15PbZrO3 piezoelectric ceramics of the perovskite family.

The data could be described by:

sδD (m3/s) = 3.7 x 10-9 exp[-168(kJ/mol)/RT]

This unusually large combined pre-exponential factor implied the occurrence of marked segregation of Ag at the grain boundaries, and a low solid solubility within the grains. It was possible, by using a semi-empirical model, to estimate metal/Ag/ceramic interface energies as a function of temperature. Values of 90kJ/mol and 0.9R were deduced for the enthalpy and entropy, respectively, of grain-boundary segregation.

Diffusion of 110mAg Tracer in Polycrystalline and Single-Crystal Lead-Containing Piezoelectric Ceramics. D.J.Lewis, D.Gupta, M.R.Notis, Y.Imanaka: Journal of the American Ceramic Society, 2001, 84[8], 1777-84