摘要
用电弧熔炼的方法制备了Ｇｄ２（Ｆｅ１－ｘＣｏｘ）１５Ｇａ２（０≤ｘ≤１０）和Ｇｄ２（Ｆｅ０８Ｃｏ０２）１７－ｙＧａｙ（０≤ｙ≤８）化合物，通过Ｘ射线衍射和磁性测量手段研究了它们的结构和磁性．实验结果表明它们都是２∶１７型结构的单相化合物．Ｇｄ２（Ｆｅ１－ｘＣｏｘ）１５Ｇａ２的单胞体积Ｖ随Ｃｏ含量的增加单调下降，而居里温度ＴＣ单调上升，１５Ｋ下的饱和磁化强度Ｍｓ随Ｃｏ含量的增加开始时略有增大，在ｘ＝０２时出现极大值，然后单调下降；对Ｇｄ２（Ｆｅ０８Ｃｏ０２）１７－ｙＧａｙ的样品，随Ｇａ含量的增加单胞体积增加，居里温度和饱和磁化强度单调下降．用Ｃｏ替代Ｆｅ，或用Ｇａ替代Ｆｅ和Ｃｏ都能导致Ｆｅ或Ｃｏ次晶格出现室温单轴各向异性，这可能与Ｇａ原子的择优占位有关．
Abstract The compounds of Gd 2(Fe 1 -x Co x ) 15 Ga 2(0≤ x ≤1 0) and Gd 2(Fe 0 8 Co 0 2 ) 17- y Ga y (0≤ y ≤8) were prepared by arc melting. Their structure and magnetic properties have been studied by means of X ray diffraction and magnetic measurements. Experimental results show that single phase compounds with the 2∶17 type structure were obtained for all samples. It was found that the unit cell volume of Gd 2(Fe 1 -x Co x ) 15 Ga 2 compounds decreases, while the Curie temperature T C increases monotonously with increasing Co concentration. The saturation magnetization M s at 1 5K first increases with increasing x , then decreases, showing a value of maximum at x= 0 2. For Gd 2(Fe 0 8 Co 0 2 ) 17- y Ga y , the unit cell volume increases, the Curie temperature and the saturation magnetization at 1 5K decrease monotonously with increasing Ga content. The substitution of Co or Ga for Fe in Gd 2Fe 17 compounds results in a change of magnetocrystalline anisotropy of Fe or Co sublattice from easy plane to easy c axis at room temperature. This is likely related to the preferential site occupancy of Ga atom.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
1997年第11期2241-2257,共17页
Acta Physica Sinica
基金
国家自然科学基金
