研究目的
To confirm the influence of shock compression on the phase transitions, remnant polarization, and dielectric susceptibility of KNbO3 ferroelectric single crystal by LGD phenomenological theory.
研究成果
Shock compression increases both the cubic to tetragonal and the tetragonal to orthorhombic phase transition temperatures. The derivative of the phase transition temperatures with respect to shock compression stain was estimated to be 21.9 °C/10?3. The orthorhombic to rhombohedral phase transition temperature decreased with increasing shock compression and the derivative of the phase transition temperatures with respect to shock compression stain was estimated to be ?144.3 °C/10?3. The remnant polarizations of the tetragonal and orthorhombic KNbO3 crystal increased by approximately 15.3% when the shock compression strain increased from 0 to 4×10?3 at 400 °C. The dielectric susceptibilities ε33 and ε22 were calculated to decrease by approximately 20% and 40% when the shock compression strain increased from 0 to 1.6×10?3 at 350 °C.
研究不足
The phase transition pressures of potassium niobate under shock compression have not been reported in previous studies; thus, the only trend of the phase transition temperatures with increasing strain induced by shock compression can be confirmed by comparison with uniaxial stress data.
