Phase transitions in PbTiO_3 micro-crystals of different size

摘要

PbTiO_3 crystal is a model ferroelectric material exhibiting perovskite-type structure, high Curie temperature (Tc = 765 K), large spontaneous polarization (Ps = 0.42 Cm~(-2)) and electrical conductivity at Tc (σ_(Tc) = 0.1 Ω~(-1)m~(-1)). A method of preparation of PbTiO_3 micro-crystals (size 1-50 μm) exhibiting isometric shapes and a method of segregating microcrystals into fractions within a narrow size range has been developed. The present work gives results of investigations on kinetics of the phase transition in micro-crystals exhibiting different dimensions. It has been found that P4mm <->