Phase transition characteristics of the relaxor-based 0.24PIN-0.51PMN-0.25PT single crystals

Phase transition characteristics of relaxor-based 0.24PIN-0.51PMN-0.25PT single crystal were investigated through combination of dielectric and piezoelectric properties measurement, hysteresis loop measurements and domain morphology observation with increasing temperature. The phase transition from rhombohedral phase to relaxor cubic phase occurs near 120 degrees C. The poled crystals exhibit dielectric properties of normal ferroelectrics below 120 degrees C with frequency independence and show no piezoelectricity over 120 degrees C with disappearance of resonance and anti-resonance peaks in the impedance spectrum. The poled crystals show clearer domain morphology than that of unpoled crystals. Square hysteresis loop feature was found to transform to double loop like feature under the temperature of about 10 degrees C lower than 120 degrees C. The double like hysteresis loop disappears and the hysteresis loop is nearly linear above dielectric maximum temperature similar to 150 degrees C. The more evident dielectric dispersion phenomenon and finer domains with width 1-3 mu m are presented in 0.24PIN-0.51PMN-0.25PT crystal, compared to 0.76PMN-0.24PT single crystal. (C) 2013 Elsevier B.V. All rights reserved.