Investigation on inhomogeneity in PMN-PT material by nonlinear pyroelectric effect

Abstract Pyroelectric effect in PMN-PT single crystal and ceramics was measured. Two pyroelectric peaks were observed in the ceramic material. But, the single crystal exhibited three pyroelectric peaks at 342, 368, 381 K, respectively. The gentle hill at 342 K demonstrates that the spontaneous polarization changes gradually during the rhombohedral-tetrogonal phase transition. The peak at 381 K was unexpected and it indicates that chemical composition is not homogeneous in the single crystal sample. The correlation between the distribution of chemical composition and dispersion of piezoelectric constant was discussed.