Peculiar Temperature Aging Effects On The Piezoelectric Constant Of Pb(Mg1/3nb2/3)O-3-Pbtio3 Single Crystal Near The Morphotropic Phase Boundary

After temperature aging, peculiar changes of the piezoelectric response of 0.67 Pb(Mg1/3Nb2/3)O(3-)0.33 PbTiO3 crystals appeared. The piezoelectric constant d(33) of the (001)-cut crystals with T(RT)similar to35degreesC abruptly rose more than 1000 pC/N in some regions after heat treatment at 65 degreesC for 12 h. For the (001)-cut crystals with T(RT)similar to74 degreesC, in spite of a fall of 40-100 pC/N after heat treatment at 65 degreesC for 12 h, the values of d33 rose 50-100 pC/N unexpectedly after the subsequent heat treatment at 85 degreesC for 4 h. The structure adjustment caused by the internal stress relaxation during heat treatment at T>T-RT accounted for the enhancement of d(33). (C) 2005 American Institute of Physics.