Ho_2Co_(17-x)Si_x化合物的结构与磁性研究

The Structure and Magnetic Properties Study of Ho 2Co 17-x Si x Compounds

研究了非磁性原子Ｓｉ 替代Ｃｏ 对Ｈｏ２Ｃｏ１７ 金属间化合物结构和磁性的影响－Ｘ 射线衍射表明，所有Ｈｏ２Ｃｏ１７ － ｘＳｉｘ（ｘ ＝ ０ ．５ ，１ ．０ ，１ ．５ ，２ ．０ ，２ ．５ ，３ ．０） 化合物都为Ｔｈ２Ｎｉ１７ 型六角结构；化合物的晶格常数和单胞体积都随Ｓｉ 含量的增加而线性降低－ 磁性测量表明，Ｈｏ２Ｃｏ１７ － ｘＳｉｘ 化合物的居里温度和饱和磁化强度随Ｓｉ 含量的增加而线性下降－ 对Ｈｏ２Ｃｏ１７ － ｘＳｉｘ 化合物，测量了补偿点温度下的磁化曲线－ 从热磁曲线测量观察到，Ｈｏ２Ｃｏ１７ － ｘＳｉｘ 化合物在ｘ ＝ ０ ．５ 时化合物呈面各向异性，当１ ．０ ≤ｘ ≤３ ．０ 时出现由易面到易轴的自旋重取向，自旋重取向温度Ｔｓｒ 随Ｓｉ 原子含量ｘ 的增加先下降，而后又上升，在ｘ ＝ ２ ．５

Effects of substituting small amounts of Si for Co on the structure and magnetic properties of Ho 2Co 17 compounds were studied by means of X-ray diffraction and magnetization measurements.All samples are of single phase with the Th 2Ni 17 type structure.The substitution of Si for Co leads to an approximately linear decrease in the unit cell volume.The analysis indicates that the Curie temperature and the magnetization strength of Ho 2Co 17-x Si x are found to decreases as x increases from 0 to 3.From theromagnetization curves measurement,it is found that Ho 2Co 17-x Si x compounds display the plane anisotropy at x=0.5.A spin reorientation occurs from based plane to C-axis for 1.0≤x≤3.0.T sr ,the temperature of spin reorientation decreases first,and then increases with the increase of Si concentration,where there is a lowest point at x=2.5.