The influence of external stress/strain on the phase transitions and dielectric properties of potassium niobate crystal

Abstract We investigated the effects of one-dimensional shock wave compression on the structural, dielectric, and ferroelectric properties of a potassium niobate ferroelectric crystal using Landau–Ginsburg–Devonshire phenomenological theory. Our results show that the cubic to tetragonal and tetragonal to orthorhombic phase transition temperatures increase with increasing shock compression and the derivative of the phase transition temperatures with respect to stain induced by shock compression was estimated to be 21.9 °C/10 −3 . Additionally, the orthorhombic to rhombohedral phase transition temperature decreased with increasing shock compression and the derivative of the phase transition temperatures with respect to stain induced by shock compression was estimated to be −144.3 °C/10 −3 . This result represents a 15.3% increase in the remnant polarization of the tetragonal KNbO 3 crystal when the stain induced by shock compression increased from 0 to 4 × 10 −3  at 400 °C. The dielectric susceptibilities e 33 and e 22 were calculated to decrease by approximately 20% and 40%, respectively, when the stain induced by shock compression increased from 0 to 1.6 × 10 −3  at 350 °C. The increase in the remnant polarization and the decrease in the dielectric properties induced by shock compression provide an effective way to improve the power output capacity of a ferroelectric-pulsed power supply.