High composition uniformity of 4″ of PIN-PMN-PT single crystals grown by the modified Bridgman method

Relaxor based ferroelectric single crystals Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) with composition near morphotropic phase boundary exhibit extraordinary piezoelectric properties. Due to the composition segregation during crystal growth, the composition and properties of PIN-PMN-PT single crystal boules are poor uniformity. In this work, uniformity of dielectric and piezoelectric properties of the crystal boules with 4″ diameter by 100 mm long were clearly improved along the crystal growth direction by the modified Bridgman method. For 70% length of the boule, TRT and Tc were around 100 °C and 160-180 °C along the growth direction, respectively. The variety of piezoelectric constant d33 is about 1500-1800pC/N in the same range of the boule. So that PIN-PMN-PT crystals will be more cost-effective and beneficial for ultrasonic applications in higher temperature region.