Growth of single crystals of high-Curie-temperature Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 ternary systems near morphotropic phase boundary

Crystal growth in xPb(In1/2Nb1/2)O-3-yPb(Mg1/3Nb2/3)O-3-zPbTiO(3) (PIMNT100x/100y/100z) ternary systems near the morphotropic phase boundary was investigated by the conventional flux method using PbO and PbO-B2O3 flux. The PIMNT crystals were obtained easily by the slow cooling of a 50PIMNT:40PbO:10B(2)O(3) (mol%) molten solution from 1230degreesC to 850degreesC. The PbO-B2O3 flux is effective for PIMNT single crystal growth. The largest PIMNT 16/51/33 crystal had dimensions of about 20mm x 10mm x 5 mm. The (001) wafers cut from the obtained crystal had transparent and opaque areas. The electron probe X-ray microanalysis (EPMA) results revealed that the compositions of the two areas differ slightly; the Ti content in the opaque area is lower than that in the transparent area. The temperature dependence of the dielectric constant showed a maximum at the tetragonal to cubic phase-transition temperature (T-c = 187degreesC), which is 30degreesC-40degreesC higher than that for a 0.68Pb(Mg1/3Nb1/3)O-3-0.32PbTiO(3) (PMNT 68/32) single crystal. A dielectric constant (epsilon(33)(T)/epsilon(0)) of 4000, a coercive field (E-c) of 7.0kV/cm, an electromechanical coupling factor (k(33)') of 80%, and a frequency constant (N-33'r) Of 1160Hzm were obtained.