DIFFUSIONAL PENETRATION OF SILVER FROM ELECTRODES INTO PZT CERAMICS

Diffusion of silver was studied in a ceramic based on lead zirconate t itanate, Pb0.95Sr0.05(Zr0.53Ti0.47)03 + 1 Wt%. Nb2O5 (PZT), by means o f a radio-tracer method. Parameters of silver diffusion and silver con tent in PZT after continuous diffusion saturation of the ceramic by th is impurity were determined in the temperature range 500-850-degrees-C . Concentration-depth profiles and silver content in the ceramic were obtained as a result of metal diffusion from the electrode during cera mic silvering. Our results show that silver has a high diffusivity. No evaporation of silver during metallization (T(max) = 750-degrees-C) w as found, but part of it (approximately 0.1 mg cm-2) penetrates into t he ceramic from the electrode to a depth of more than 1000 mum, and th e silver concentration varies from approximately 2 x 10(19) to approxi mately 2 x 10(18) at cm-3. The silver concentration does not exceed 0. 2 at% at diffusion saturation of the ceramic during 100-120 h over the temperature range 650-850-degrees-C.