Investigation of Electroplating-Induced Degradation of PMZNT Relaxor Ferroelectrics

Abstract

Resistance degradation of lead magnesium niobate-based (PMZNT) ceramics during nickel electroplating was investigated using resistivity measurement and auger electron spectroscopy (AES) analysis. It was found that the resistivity of the ceramics remained nearly unchanged at the initial stage of the electroplating, and, as electroplating time increased, the resistivity decreased rapidly. An AES depth profile analysis of a degraded specimen showed oxygen content in the surface to be lower than the theoretical value, and the relationship of oxygen content and detection depth was obtained. The results indicated that Pb 2+ and Nb 5+ were reduced to lower valence states and oxygen in the lattice was lost, thereby leading to a generation of oxygen vacancies. Hence, the conductivity of the dielectrics was enhanced. The results also indicated that only the outermost surface had suffered the reducing effect induced by hydrogen generated during nickel electroplating, whereas the bulk material remained impervious.