【摘要】 通过X射线衍射分析和磁测量研究了Gd Fe Co Cr四元系中对应于化学式Gd3(Fe ,Co ,Cr) 2 9且Gd含量为一定值的截面内富Fe,Co区的相关系 ,重点探索了高Co含量 3∶2 9型化合物合成的可能性 ,研究了 3∶2 9型Gd3(Fe1 -xCox) 2 9-yCry 化合物的结构与磁性 .研究结果表明 ,获得 3∶2 9型单相Gd3(Fe1 -xCox) 2 9-yCry 化合物的范围为 :y =5 ,0≤x≤ 0 .7;y =5 .5 ,0 .7≤x≤ 0 .8和y =6 ,0 .8≤x≤ 0 .9.基于对Gd3(Fe1 -xCox) 2 9-yCry 化合物成相条件的研究 ,成功地合成了纯Co基Gd3Co2 9-yCry 化合物 ,其固溶范围为 6 .5≤y≤ 7.3.3∶2 9型单相Gd3(Fe1 -xCox) 2 9-yCry 化合物的晶体结构都属于单斜晶系 ,Nd3(Fe,Ti) 2 9型结构 ,空间群为A2 m .得到 3∶2 9型单相Gd3(Fe1 -xCox) 2 9-yCry 化合物的固溶极限即Co含量的极大值与稳定元素Cr含量有关 .Co原子的含量越高 ,所需稳定元素Cr的含量越大 .值得注意的是 ,用Co原子替代Fe原子会导致Gd3(Fe1 -xCox) 2 9-yCry 化合物磁晶各向异性的显著改变 .当x≥ 0 .4时 ,化合物的磁晶各向异性从易面型转变为易轴型更多还原

【Abstract】 Based on a study of the phase relation in the Fe\| and Co\|rich region of the equi\|gadolinium content section with the Gd content corresponding to the chemical formula Gd 3(Fe,Co,Cr) 29 in the Gd Fe Co Cr quaternary system, formation, structure and magnetic properties of the 3∶29 type Gd 3(Fe 1- x Co x ) 29- y Cr y compounds have been investigated. It has been found that the composition range of formation of the single phase Gd 3(Fe 1- x Co x ) 29- y Cr y Compounds is 0≤ x ≤0.7 for y =5.0, 0.7≤ x ≤0.8 for y =5.5, and 0.8≤ x ≤1.0 for y =6.0. A pure Co based Gd 3Co 29- x Cr x compound series have been synthesized. The solubility limit of the Cr atoms in the Gd 3Co 29- x Cr x compounds was found to be from x =6.5 to x =7.3. The results indicate that all the synthesized Gd 3(Fe 1- x Co x ) 29- y Cr y compounds crystallize in Nd 3(Fe,Ti) 29 type structure of the monoclinic system and the space group A2/m .The solubility limit of Co atoms in the Gd 3(Fe 1- x Co x ) 29- y Cr y compounds increases with increasing the stabilizing element Cr. It is noteworthy that substitution of Co for Fe leads to a remarkable change of the magnetocrystalline anisotropy of the Gd 3(Fe 1- x Co x ) 29- y Cr y compounds. When x ≥0.4 the anisotropy changes from the easy plane type to the uniaxial type, which is important for permanent magnet application.更多还原