Study of Phase Transition and Domain Evolution Behavior in PZN-PT Single Crystal

(1-x)Pb(Zn1/3Nb2/3)O-3-xPbTiO(3)(PZN-PT) has attracted large attention due to its ultrahigh piezoelectric and dielectric properties. However, its piezoelectric properties fluctuate due to its multiphase coexistence and complicated domain structures. The phase transition at high temperatures is still confusing. In present work, the phase transition was studied by the high temperature X-ray diffraction technique. The split of XRD peak at (001) revealed the coexistence of rhombohedral (R) and tetragonal (T) phases from 100 degrees C to 170 degrees C. The third peak, attributed to monoclinic phase, was found accompanied with R-T phase transition. In the range from 175 degrees C to 210 degrees C, the XRD peak becomes broader and tends to disappear, which means the transition from ferroelectric tetragonal phase to paraelectric cubic phase. The evolution behavior of the domains with the phase transition was investigated by high temperature polarizing microscope.