Piezoelectric properties and phase transitions of ⟨001⟩-oriented Pb(Zn1/3Nb2/3)O3-PbTiO3 single crystals

Electric-field-induced phase transitions and piezoelectric properties of <001>-oriented Pb(Zn1/3Nb2/3)O-3-xPbTiO(3) single crystals for x=4.5% and 8% (PZN-4.5%PT and PZN-8%PT) have been investigated as a function of temperature. It was found that the piezoelectric properties and phase transitions for both crystals are strongly dependent on temperature. The measurements of polarization and strain as a function of unipolar electric field show that the field for the rhombohedral-tetragonal phase transition decreases linearly with temperature in the range between 25 and 105 degreesC. Thus, raising the temperature can stabilize the tetragonal phase in <001>-oriented PZN-PT crystals. Longitudinal piezoelectric constant d(33) in the rhombohedral phase increases with temperature for both crystals; in PZN-4.5%PT the slope itself increases significantly at temperatures over 60 degreesC. In the field-induced tetragonal phase, there is little change in d(33) for PZN-8%PT within the temperature range investigated, while in PZN-4.5%PT a slight increase of d(33) with temperature was observed at temperatures above 80 degreesC. (C) 2002 American Institute of Physics.