Comprehensive properties and thermal stability of Ta2O5-doped PIN-PHT ceramics

Herein, high-performance 0.11 Pb(In1/2Nb1/2)O3-0.89 Pb(Hf0.47Ti0.53)O3-0.8Ta2O5 (PIN-PHT-0.8Ta) ceramics are successfully synthesized. In addition, performance improvement is comprehensively analyzed from view-points of microstructure, phase structure and electrical properties. Experimental results reveal that the addition of Ta2O5 changes phase structure of PIN-PHT ceramics from ferroelectric tetragonal phase to rhombohedral phase. This leads to the appearance of morphotropic phase boundaries (MPBs). At the same time, the addition of Ta2O5 reduces grain size and enhances grain uniformity. Also, Ta2O5 doping improves internal and external contribution of piezoelectric response, which greatly improves dielectric, piezoelectric and ferroelectric prop-erties of PIN-PHT. Key performance parameters include d33, kp, TC, epsilon r and tan delta, which are found to be 630 pC/N, 0.73, 322.6 degrees C, 1917 and 1.55%, respectively. In particular, thermal stability of PIN-PHT-0.8Ta ceramics is found to be higher than PZT-based ceramics, as well as d33 value and performance retention rate of PIN-PHT-0.8Ta are found to be 560 pC/N and 89% at 300 degrees C, respectively, which are far superior to commercial PZT-5 and PZT-8 ceramics. These properties indicate potential of PIN-PHT-0.8Ta ceramics in high-temperature applications.