Large Piezoelectric Constant of High-Curie-Temperature Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)–PbTiO3 Ternary Single Crystal near Morphotropic Phase Boundary

Abstract

Single crystals, with high Curie temperature (Tc), of the xPb(In1/2Nb1/2)O3–yPb(Mg1/3Nb2/3)–zPbTiO3 (PIMNT100x/100y/100z) ternary system near a morphotropic phase boundary were successfully grown by a conventional flux method using PbO–B2O3 flux. The crystals were grown in a platinum crucible by mass crystallization achieved through slow cooling of a 50PIMNT 16/51/33: 40PbO: 10B2O3 (mol%) molten solution from 1,230 to 850°C at 1.2°C/h. The obtained crystals had a perovskite structure. The largest crystal had dimensions of about 20×10×5 mm3. The dielectric constant after poling, ε33T/ε0, was 3,100 and the dissipation factor was 0.8% at room temperature. The temperature dependence of the dielectric constant showed a maximum at the tetragonal-to-cubic phase-transition temperature, Tc=187°C. The piezoelectric constant of d33=2,200 pC/N is the highest value so far reported for any piezoelectric material with Tc>185°C.