Enhancing the Performance of PZT-5H Piezoelectric Ceramics by Vacuum Sintering

This study comparatively investigates the effects of vacuum sintering and traditional sintering on the structure and electrical properties of lead zirconate titanate (PZT) 5H (PZT-5H) piezoelectric ceramics. The density of the vacuum-sintered ceramics increases from 7.67 g/cm3 (for traditionally sintered ceramics) to 7.98 g/cm3. Importantly, the dielectric constant (εr), remnant polarization (Pr), planar electromechanical coupling coefficient (kp), and piezoelectric coefficient (d33) for the PZT-5H ceramics increase by 35%, 20%, 9%, and 12%, respectively, when vacuum sintering is employed instead of traditional sintering. Over a temperature range from room temperature to 180 °C, the d33 variation measured by the resonant method is only about 4% for the vacuum-sintered PZT-5H ceramics. High-temperature impedance spectroscopy analysis reveals that vacuum sintering reduces the hole concentration in PZT-5H ceramics, leading to significant improvements in their dielectric and piezoelectric performance. This research demonstrates that vacuum sintering is a simple and effective method to enhance the density, dielectric, and piezoelectric properties of PZT-5H ceramics.