Piezoelectric properties of a high curie temperature Pb(In1/2Nb1/2)O-3-PbTiO3 binary system single crystal near a morphotropic phase boundary

High-quality piezoelectric (1-x)Pb(In1/2Nb1/2)O-3-xPbTiO(3) binary system s ingle crystals near a morphotropic phase boundary were successfully grown b y a conventional flux method using PbO-PbF2-B2O3 flux. The largest crystal had dimensions of about 20 mm x 10 mm x 5 mm. The permittivity shows a shou lder at the ferroelectric rhombohedral to tetragonal phase transition tempe rature, T-fr = 100 degrees C, and then has a maximum (35000 at 1 kHz) at th e ferroelectric tetragonal to paraelectric cubic phase transition temperatu re, T-c = 260 degrees C. The electromechanical coupling coefficient in rect angular bar mode, k(33)' = 78%, for phased array ultrasonic transducers was obtained by using the rhombohedral 0.72Pb(In1/2Nb1/2)O-3-0.28PbTiO(3) sing le crystal oriented along the [001] axis in the shape of a rectangular bar of 0.2 mm in width, 0.5 mm in thickness and 9 mm in in length. The k(33)' = 78% is the highest value reported so far among all the piezoelectric mater ials with a T-c more than 250 degrees C.