Ga替代对Gd_2(Fe,Co)_(17)化合物磁性的影响

Effect of Ga Substitution on Magnetic Properties of Gd 2(Fe,Co) 17 Compounds

通过Ｘ射线衍射和磁性测量手段研究了Ｇｄ２（Ｆｅ０．８Ｃｏ０．２）１７－ｘＧａｘ（０≤Ｘ≤８）化合物的结构和磁性。实验结果表明Ｇｄ２（Ｆｅ０．８Ｃｏ０．２）１７－ＸＣａＸ化合物均为菱方的Ｔｈ２Ｚｎ１７型结构，单胞体积Ｖ随Ｃａ含量的增加单调上升，居里温度Ｔｃ和饱和磁化强度Ｍｓ随Ｇａ含量的增加而单调下降。粉末取向样品的Ｘ射线衍射结果表明，随Ｇａ含量的增加，化合物的室温易磁化方向由易面转变为易轴，Ｇｄ２（Ｆｅ．８Ｃｏ０．２）１７－ＸＣａＸ化合物的３ｄ亚晶格出现室温单轴各向异性可能与Ｃａ原子的择优占位有关。

The structure and magnetic properties of Gd 2(Fe 0 8 Co 0 2 ) 17 x Gax(0≤X≤8)compounds have been studied by means of X ray diffraction and magnetic measurements.The experimental results show that single phase compounds with the rhombohedral Th 2Zn 17 type structure are obtained for all samples.It was found that the unit cell vol￣umes V of Gd 2(Fe 0 8 Co 0 2 ) 17 x Ga x compounds increase and the Curie temperature T C and saturation magnetizationM s decrease monotonously with increasing Ga concentration.X ray diffraction mesurements on magnetically aligned powders show that the easy magnetization direction of Gd 2(Fe 0 8 Co 0 2 ) 17 x Ga xcompounds changes from basal plane to c axis with increasing Ga concentration.The room temperature uniaxial anisotropy in Gd 2(Fe 0 8 Co 0 2 ) 17 x Ga x compounds with higher Ga concentration is likely relative to the preferential site occupancy of Ga atom.