K. Harada et al., CRYSTAL-GROWTH AND ELECTRICAL-PROPERTIES OF PB((ZN1 3NB2/3)(0.91)TI-0.09)O-3 SINGLE-CRYSTALS PRODUCED BY SOLUTION BRIDGMAN METHOD/, Journal of the American Ceramic Society, 81(11), 1998, pp. 2785-2788
Piezoelectric Pb((Zn1/3Nb2/3)(0.91)Ti-0.09)O-3 (PZNT 91/9) single crys
tals 40 mm in diameter were successfully grown from solution by the Br
idgman method with a PbO flux. The crystals were grown in a platinum c
rucible heated to 1130 degrees C, Growth rate was 0.35 mm/h. The obtai
ned crystals were similar to 40 mm in diameter x 20 mm in length and w
ere a rust-brown color. The Curie temperature, T-C, ranged from 175 de
grees to 185 degrees C, and the dielectric constant before poling at r
oom temperature was 2000-8900 within a wafer. After electrical poling,
specimens had electromechanical coupling coefficients in rectangular
bar mode, k(33'), of 79%-88%, which were larger than for PZT ceramics
(k(33') < 70%), These PZNT 91/9 single crystals grown by the Bridgman
process satisfy the requirements for array-type transducers used in ec
hocardiographic equipment. Results confirm that the Bridgman method is
useful for mass-producing large crystals of PZNT 91/9.