Diffusion and electromigration of silver in PZT and HTSC ceramics

Abstract

Abstract Diffusion and electromigration of silver in ferroelectric ceramics of lead zirconate-titanate (PZT) PbZr0.54Ti0.46O3 and diffusion of silver in high temperature superconducting (HTSC) ceramics YBa2Cu3O7−x has been studied in air. The diffusion coefficient D in PZT varies from ≈ 10−10cm2/s at 370°C to ≈ 10−7 cm2/s at 700°C. The temperature dependence of D follows the relationship D = 0.19 exp (−1.21 eV/ kT) cm2/s. The electromigration of silver in PZT has been studied from 150 to 460°C in a constant electric field E = 700-1500 V/cm. Silver was found to migrate predominantly to the cathode. Above ≈ 400°C the regions of the local penetration of silver to the cathode were observed. The diffusion in HTSC has been studied in porous ceramics having a porosity varying from 17 to 34%. The silver concentration in a volume and the diffusion coefficient are found to increase with the porosity. In the range 500-800°C the diffusion coefficient D varies from ≈ 10−10 cm2/s to ≈ 10−7 cm2/s. The temperature depend...