Abstract The uniaxial compression stress dependence of the phase transitions and dielectric properties of a potassium niobate (KNbO3) ferroelectric crystal were investigated using Landau–Ginsburg–Devonshire phenomenological theory. The results showed that (1) uniaxial stress along [001]c could induce a spontaneous polarization change from the [001]c direction to the [010]c or [100]c directions and from the [011]c, [101]c directions to the [110]c direction; (2) the cubic to tetragonal and the tetragonal to orthorhombic phase transition temperatures increased, while the orthorhombic to rhombohedral phase transition temperature decreased as the uniaxial stress was increased; and (3) spontaneous polarization increased as the uniaxial stress was increased for the tetragonal and orthorhombic phases. The uniaxial stress dependence of the dielectric susceptibility also showed that a flatter Gibbs free energy profile corresponds with a greater expandability, contractibility, and rotationality of the polarization (which indicates a higher dielectric susceptibility), while a steeper Gibbs free energy profile corresponds with a reduced expandability, contractibility, and rotation of the polarization (which indicates a lower dielectric susceptibility).

中文翻译：

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单轴应力对铌酸钾铁电单晶相变和介电性能的影响

摘要 使用 Landau-Ginsburg-Devonshire 现象学理论研究了铌酸钾 (KNbO3) 铁电晶体的相变和介电特性的单轴压缩应力依赖性。结果表明，（1）沿[001]c的单轴应力可以引起从[001]c方向到[010]c或[100]c方向以及从[011]c、[101]方向的自发极化变化c方向到[110]c方向；(2)随着单轴应力的增加，立方向四方、四方向正交相变温度升高，而正交向菱形相变温度降低；(3) 自发极化随着四方相和正交相的单轴应力的增加而增加。