Large piezoelectric constant of high-Curie-temperature Pb(In1/2Nb1/2)O3-Pb(Mg1/3 Nb2/3)-PbTiO3 ternary single crystal near morphotropic phase boundary

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.