Y_2(Co,Si)_(17)化合物的结构与磁晶各向异性

Structure and Magnetocrystalline Anisotropy of Y_2(Co,Si)_(17) Compounds

采用真空电弧熔炼法制备了 Y2 Co17- x Six化合物。用 X-射线衍射和磁性测量方法 ,研究了化合物的晶体结构和内禀磁性。实验结果表明 ,随 Si原子浓度增加 ,Y2 Co17- x Six化合物的居里温度和饱和磁化强度急剧下降。本文重点讨论了 Si原子在 Co次晶格的四个不同晶位择优占位与 Co次晶格磁晶各向异性从易面转变为易轴的演化关系 ,其中 1 8h晶位对 Co次晶格各向异性负贡献起重要作用。

Y 2Co 17-x Si x compounds with Si concentration up to x=4 were prepared by vacuum arc melting.The structure and intrinsic magnetic properties of these compounds were studied by means of X-ray diffraction and magnetic measurements.The experiments show that the Curie temperature and saturated magnetizations of the Y 2Co 17-x Si x compounds decrease dramatically with increasing Si concentration.In this paper,a special attention is paid to the evolution between the preferred site occupation of Si atoms over the four available crystallographic sites on the Co sublattice and a sign reversal of the magnetocrystalline Co sublattice anisotropy from easy plane to easy axis.The 18h site plays an important role to contribute negatively to the Co sublattice anisotropy in R 2Co 17 compounds.