Ferroelectricity of Pr ₂ Ti ₂ O ₇ ceramics with super high Curie point

AbstractThe perovskite-like layer structured praseodymium titanate (Pr2Ti2O7; PTO) is a good candidate for high temperature piezoelectric application because of its high Curie point. Single phase, dense, textured PTO ceramic was prepared by spark plasma sintering using a two-step method for the first time. The Lotgering orientation factor was 0·87. The Curie point of PTO is >1555±5°C. The dielectric constant increases with grain size due to the decreasing effect of grain boundaries and increasing extrinsic contribution from the ferroelectric domain wall movement. For the first time, PTO was shown to be ferroelectric because it showed piezoelectric activity after poling (d33 = 0·5±0·1 pC N–1).