Hydrogen-induced degradation of PMN-based relaxor ferroelectrics during nickel electroplating

The effects of nickel electroplating on electrical properties of PMN-based relaxor ferroelectrics were studied by measuring the resistance and tempera ture dependence of dielectric constant and dissipation factor. It was found that the insulation resistivity of the specimens declined nonlinearly with electroplating time. Additionally, the dielectric constant and dissipation factor were reduced and enhanced respectively. X-ray photoelectron spectro scopy (XPS) analysis showed that Nb5+ and Pb2+ were partially reduced to Nb 4+ and metallic Pb by hydrogen during nickel electroplating, which conseque ntly generated oxygen vacancies and conductive electrons in view of defect chemistry, thereby the conduction was enhanced. On the basis of our experim ents, the degradation of electrical properties of PMN-based ferroelectrics was ascribed to resistive leakage resulting from Nb5+ and Pb2+ reductions t o lower charge states by hydrogen. (C) 2001 Elsevier Science Ltd. All right s reserved.