Growth of the relaxor based ferroelectric single crystals Pb(In _1/2Nb_1/2)O₃-Pb(Mg_1/3Nb _2/3)O₃-PbTiO₃ by vertical Bridgman technique

The relaxor-based ferroelectric single crystals Pb(In_1/2Nb _1/2)O₃- Pb(Mg_1/3 Nb_2/3)O ₃-PbTiO₃ were grown successfully using the vertical Bridgman technique. The crystals were spontaneously nucleated and induced to grow by the seed respectively, with diameter of Φ25-40 mm and length of 80-170 mm. The [001]-oriented wafers of as-grown crystals showed the excellent electrical characterizations (ε∼5500, tanδ∼1.35%, d ₃₃ ∼1900pC/N, k₃₃∼0.9). Both the higher rhombohedral-tetragonal phase transition temperature (T_r/t ∼100-120°C) and Curie temperature (T_c ∼170-200°C) enlarged the operating temperature range of the devices. The crystals had the stable time dependence of piezoelectric properties. Therefore, the successful growth and high performance made the crystal be a promising candidate for the ultrasonic applications.