Optimized piezoelectric properties and temperature stability in PSN-PMN-PT by adjusting the phase structure and grain size

For relaxor ferroelectric materials, improving the piezoelectric properties and temperature stability simultaneously is still a great challenge up to now. In this work, the structure, electric properties, and thermal stability of xPSN-(1 - x)PMN-0.4PT (x = 0.15, 0.29, 0.43, and 0.5) ceramics were studied systematically by experiment and phase field simulation. A high Curie temperature T-c of 255celcius and good longitudinal electricmechanical coupling factor k(33) of 0.75 and piezoelectric constant d(33) of 650 pC/N are achieved in x = 0.43 ceramics with monoclinic C and tetragonal phases coexistence at room temperature. At 30celcius, this composition ceramics sintered at 1260celcius shows the remnant polarization P-r and coercive field E-c are about 36.8 mu C/cm(2) and 8.2 kV/cm respectively. Moreover, as the temperature increases to 150celcius, these values remain as high as 22.6 mu C/cm(2) and 5.7 kV/cm. In the temperature range of 30-230celcius, the variation of k(33) and d(33) is about 24% and 25%. These high piezoelectric performance and superior temperature stability are related to the more complex domain structures caused by phase coexistence and larger grains with more stable domain structure due to internal stress. The former is beneficial in improving the piezoelectric properties, and the latter dominates the enhanced temperature stability.