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

Abstract

Electric-field-induced phase transitions and piezoelectric properties of 〈001〉-oriented Pb(Zn1/3Nb2/3)O3–xPbTiO3 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 °C. Thus, raising the temperature can stabilize the tetragonal phase in 〈001〉-oriented PZN–PT crystals. Longitudinal piezoelectric constant d33 in the rhombohedral phase increases with temperature for both crystals; in PZN–4.5%PT the slope itself increases significantly at temperatures over 60 °C. In the field-induced tetragonal phase, there is little change in d33 for PZN–8%PT within the temperature range investigated, while in PZN–4.5%PT a slight increase of d33 with temperature was observed at temperatures above 80 °C.