R(Fe_(1-x)Ni_x)_(11.3)Nb_(0.7)化合物的磁性

MAGNETIC PROPERTIES OF R(Fe_(1-x)Ni_x)_(11-3)Nb_(0-7) COMPOUNDS

用Ｘ 射线衍射和磁测量手段研究了Ｎｉ 部分替代Ｆｅ 对具有Ｔｈ Ｍｎ１２ 结构的ＲＦｅ１１－３Ｎｂ０－７（ Ｒ＝ Ｇｄ ，Ｔｂ ，Ｄｙ ，Ｈｏ，Ｅｒ 和Ｙ） 化合物的结构与磁性的影响．研究表明，Ｎｉ 部分替代Ｆｅ 不改变晶体结构，但引起了晶胞体积收缩．随着Ｎｉ 含量的增加，居里温度ＴＣ 迅速上升，而饱和磁化强度Ｍｓ 则单调减小．Ｎｉ 部分替代Ｆｅ 还导致了Ｆｅ 次晶格的轴各向异性的迅速降低和ＲＦ１１－３Ｎｂ０－７（ Ｒ＝ Ｔｂ ，Ｄｙ ，Ｅｒ） 化合物中自旋重取向温度Ｔｓｒ 的变化．Ｔｓｒ与Ｎｉ 含量的关系用晶场理论给出了定性的解释．

Structure and magnetic properties of R (Fe 1-x Ni x ) 11 3 Nb 0 7 ( R =Gd,Tb,Dy,Ho,Er and Y) compounds have been studied by means of X\|ray diffraction and magnetic measurements. Substitution of Ni for a fraction of Fe does not change the structure of R Fe 11.3 Nb 0.7 ,but leads to the contraction of the unit cell volume, the rapidly increasing of the Curie temperature and monotonic decreasing of saturation magnetization. It is notable that introduction of Ni leads to the sharply decline of the easy\|axis anisotropy of Fe sublattice and the changes of the spin reorientation temperature T sr of R Fe 11 3 Nb 0 7 ( R =Tb,Dy,Er). A qualitative explanation of the relationship of T sr and Ni content is given based on the theory of crystal field.