Phase Transformation Sequences in As-Grown PZN-4.5%PT Single Crystals

The phase transformation sequence in as-grown PZN-4.5%PT single crystal has been investigated by means of dielectric permittivity measurements and high-resolution synchrotron x-ray diffraction. The results show that the crystal undergoes the R-T(R)-M_c-C transformation path during zero-field heating from 25degC to 160degC, where R, T, Mc and C are the rhombohedral, tetragonal, M_c-type monoclinic, and cubic phases, respectively. \´T(R)" represents that dominant T domains coexist with smaller fraction of R domains. Our results indicate that both the R-T and R-M_c transformations are first-order, while the T-M_c-C transformation is second-order in nature.