Piezoelectric materials Pb(In/sub 1/2 /Nb/sub 1/2 /)O/sub 3/-Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/ -PbTiO/sub 3/ with high Curie temperatures and large piezoelectric constants

摘要

Piezoelectric ceramics and single crystals of xPb(In/sub 1/2 /Nb/sub 1/2 /)O/sub 3/-yPb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/-zPbTiO/sub 3/ (PIMNT100x/100y/100z) ternary systems have been investigated in order to develop a new piezoelectric material with high Curie temperature, Tc. Firstly, large coupling factor, kp=67%, piezoelectric constant, d/sub 33/=510 pC/N, and relatively high Tc=197/spl deg/C of PIMNT 16/51/33 ceramic were confirmed. Secondly, PIMNT single crystals were grown by the flux method and the solution Bridgman method using a PbO-B/sub 2/O/sub 3/ flux and their electrical properties were confirmed. The selected composition was PIMNT 16/51/33. The obtained crystals had excellent electrical properties in the [001] plane: the dielectric constant /spl epsiv//sub 33//sup T/ //spl epsiv//sub 0/=4000, piezoelectric constant d/sub 33/=2200 pC/N, coupling factor k/sub 33/'=80%, which are almost the same as those of the PZNT 91/9 and PMNT 68/32 single crystals. Moreover, they had a large coercive field, Ec=7.0 kV/cm, due to the high Tc=187/spl deg/C, which is about 1.5 times greater than that of the PMNT 68/32 single crystal and a high frequency constant, N/sub 33/'r=1160 Hzm, which is 1.4 times higher than that of the PZNT 91/9 single crystal. In view of their large coercive field and high frequency constant, single crystals of PIMNT 16/51/33 are a candidate piezoelectric material with a wide application field.