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

Single crystals, with high Curie temperature ( T c ), of the x Pb(In 1/2 Nb 1/2 )O 3 – y Pb(Mg 1/3 Nb 2/3 )– z PbTiO 3 (PIMNT100 x /100 y /100 z ) ternary system near a morphotropic phase boundary were successfully grown by a conventional flux method using PbO–B 2 O 3 flux. The crystals were grown in a platinum crucible by mass crystallization achieved through slow cooling of a 50PIMNT 16/51/33: 40PbO: 10B 2 O 3 (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 mm 3 . The dielectric constant after poling, ε 33 T / ε 0 , 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, T c =187°C. The piezoelectric constant of d 33 =2,200 pC/N is the highest value so far reported for any piezoelectric material with T c >185°C.