TEMPERATURE STABILITY OF RESONANT-FREQUENCY OF TERNARY PZT CERAMICS AT THE MPB BY VARIATION OF SINTERING AND POLING TREATMENT

The temperature coefficient of resonant frequency (TCF) of Pb[formula omitted] piezoelectric ceramic near the region of morphotropic phase boundary (MPB) is studied under the influence of conventional sintering and poling process. With the optimum sintering condition: sintered at 1280°C for 3 h, a tight tolerance (±10 ppm/°C) of the TCF is obtained in the poling field range of 1.0 to 4.5 kV/mm. Concerning the variation trend of the TCF, these processing conditions (sintering temperature, sintering time, poling field and poling temperature) are found to be interrelated. From the examination of microstructure, X-ray diffraction, and 90° domain reorientation, the anomalous behaviour of the TCF may be related to which phase concentration is dominant in the region of tetragonal and rhombohedral phase coexistence, that comes from the MPB region is changed. © 1991, Taylor & Francis Group, LLC. All rights reserved.