Investigation of dipolar defects in (1-x)Pb(Zn1/3Nb2/3)O3-xPbTiO3 single crystals using different poling methods

The temperature dependence of piezoelectric, pyroelectric, and dielectric properties have been measured for [001] and [111] oriented 0.92Pb(Zn1/3Nb2/3)O-3-0.08PbTiO(3) (PZN-8%PT) and 0.955Pb(Zn1/3Nb2/3)O-3-0.045PbTiO(3) (PZN-4.5%PT) single crystals poled by two different poling methods, i.e., room temperature (RT) poling and poling through field cooling (FC). Compared with the RT poling case, some interesting features have been found in the FC poled [001] oriented crystal but not in the [111] oriented crystal. These features include the enhancement of piezoelectric properties, lowering of the transition temperature from rhombohedral to tetragonal phase, increasing the amplitude of the spontaneous polarization in the tetragonal phase region, and the decrease of the dielectric constants in the tetragonal phase. These results revealed that the dipolar defects in the crystals are formed between the B and O sites in the ABO(3) perovskite structure. (c) 2007 American Institute of Physics.