The effect of segregation during the growth of relaxor ferroelectric PMNT single crystals

摘要

Relaxor-based ferroelectric (1-x)PMN-xPT (x=0.2-0.4) single crystals were grown by a modified Bridgman method. The segregation during the growth of (1-x)PMN-xPT single crystals directly from melt was investigated by several ways for the samples cut from initial part and the end part of a boule. The effect of segregation during the growth of solid solution (1-x)PMN-xPT single crystals was verified in melting points from DTA analysis, lattice structures from XRD and other electric properties. The segregation coefficient k is about 0.95 during the growth of PMNT 76/24 single crystal. In order to improve the homogeneity within a boule, the effect of segregation must be taken into account to grow large high quality (1-x)PMN-xPT single crystals.