The effects of BaZrO₃ addition on the structural and electrical properties of BaTiO₃-based base-metal-electrode (BME) multilayer ceramic capacitor (MLCC) ceramics were investigated. Dielectric compositions containing 0–9 wt% BaZrO₃ were fabricated using a conventional MLCC process, and their crystal structure, dielectric behavior, temperature stability, frequency stability, and insulation resistance were evaluated. X-ray diffraction and Rietveld refinement confirmed the formation of a single-phase perovskite structure for all compositions. Increasing BaZrO₃ content resulted in a systematic shift of diffraction peaks toward lower angles and an increase in unit-cell volume from 64.61 to 66.05 ų, indicating successful Zr incorporation into the BaTiO₃ lattice. The dielectric permittivity increased with BaZrO₃ addition and reached a maximum value of approximately 2,110 at 6 wt%, while dielectric loss decreased significantly. Capacitance stability against temperature and frequency variations was markedly improved with increasing BaZrO₃ content. In addition, insulation resistance increased substantially over the investigated temperature range, demonstrating enhanced electrical reliability.

In this paper, PZT piezoelectric ceramic specimens with 4 compositions (Zr/Ti=50/50, 53/47, 56/44, 58/42) in Pb(Zr,Ti)O3 system were fabricated. We studied effects of poling strength and thermal aging on the temperature characteristics of eletromechanical coupling factor k31 of the specimens, which were poled with the DC electric fields, 1.5, 2.5 and 3.5 kV/mm respectively and thermally aged for an hour at 200℃. The eletromechanical coupling factor k31 of the specimen with the composition Zr/Ti=53/47, nearest to the morphotropic phase boundary decreased the most greatly, irrelevant to the intensity of poling field, due to 1st thermal aging. And the temperature coefficient of eletromechaical coupling factor k31 was(-) in the ereragonal phase composition and (+) in the rhombohedral phase composition, which is reverse in the temperature coefficient of resonance frequency. It is interesting that eletromechanical coupling factor k31 of PZT ceramics is shown to be able to be able to increase as temperature increase in the interval -20~80℃.