【摘要】 用磁测量和X-射线衍射方法研究了R₁₅Fe₇₈B₇（R=Pr,Nd,Sm,Gd,Y）的磁晶各向异性。发现R=Pr,Gd和Y时,无论室温或低温,c轴都是易磁化方向;R=Sm时,易磁化方向都是在与c轴垂直的基面内;而R=Nd时,易磁化方向随温度变化。在室温时,c轴是易磁化方向,但当温度低于140K时,易磁化方向相对c轴形成一个θ角度。利用Sucksmith-Thompson方法估算了R₁₅Fe₇₈B₇的磁晶各向异性常数K₁和K₂的数值和符号;测量了θ与温度的依赖关系。并通过测定Nd₁₅Fe₇₈B₇和Y₁₅Fe₇₈B₇的磁晶各向异性及其随温度的变化,进一步分析了Nd₁₅Fe₇₈B₇中Nd和Fe不同次点阵对磁晶各向异性的贡献。更多还原

【Abstract】 The magnetocrystalline anisotropy of R₁₅Fe₇₈B₇（R=Pr, Nd, Sm, Gd and Y） has been studied by magnetic measurement and X-ray diffraction method. A variety of magnetocrystalline anisotropy of R₁₅Fe₇₈B₇ has been found. When R=Pr. Gd or Y, the direction of easy magnetization is along the c-axis both at high and low temperature, when R=Sm, it lies in the basal plane perpendicular to c-axis. When R=Nd, it changes with temperature, at room temperature, the direction of easy magnetization is along the c-axis, but below 140K, it deviates from c-axis with an inclinaion angle θ. The anisotropy constants K₁ and K₂ of R₁₅Fe₇₈B₇ have been calculated by using Sucksmith-Thompson’s method and the declination angle θ of Nd₁₅Fe₇₈B₇ can be found as a function of temperature. Furthermore, the magnetocrystalline anisotropy and its temperature dependence of Nd and Fe sublattices have been studied by investigating the magnetocrystalline anisotropy of Y₁₅Fe₇₈B₇.更多还原