Er_3(Fe,Co,M)_(29)化合物(M=Cr,V,Ti,Mn,Ga,Nb)的结构与磁性  

Structure and magnetic properties of Er_3(Fe, Co, M)_29 compounds (M=Cr, V, Ti, Mn, Ga, Nb)

作　　者：罗鸿志[1] 贾琳[1] 李养贤[2] 孟凡斌[2] 申江[3] 陈难先[3] 吴光恒[1] 杨伏明[1] 

机构地区：[1]中国科学院物理研究所北京凝聚态物理国家实验室,北京100080 [2]河北工业大学材料学院,天津300130 [3]北京科技大学应用物理研究所,北京100083

出　　处：《物理学报》2005年第11期5246-5250,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:TG2000067106)资助的课题.~~

摘　　要：合成了Er3Fe29-x-yCoxMy化合物(M=Cr,V,Ti,Mn,Ga,Nb)并用x射线衍射和磁测量等手段研究了它们的结构和磁性.发现Fe基Er3(Fe,M)29化合物结晶成哑铃对Fe-Fe无序替代的Th2Ni17型结构(P63/mmc空间群)而不能形成Nd3(Fe,Ti)29型结构,因此其化学式也可以用Er2-n(Fe,M)17+2n(n=0.2)表示.当Er3Fe29化合物中部分Fe原子被M原子所取代时,其居里温度均有一定程度的提高.所有Er3(Fe,M)29化合物在室温均为易面型各向异性.当Er3(Fe,M)29(M=Cr,V)中的部分Fe原子被Co原子取代且Co原子数与Fe原子数达到一定比值时,得到一个单斜结构的新相.磁测量表明Er3Fe19.5Co6V3.5在室温可能为单轴各向异性,在162K出现自旋重取向,其各向异性由易轴型变为易面型.在5K下于难磁化方向磁化时观察到一个一级磁化过程(FOMP).A series of Er3（Fe, Co, M）29（M = Cr, V, Ti, Mn, Ga, Nb） compounds has been synthesized and their structure and magnetic properties have been investigates by means of x-ray diffraction and magnetic measurements. It is found that the Fe-based Er3（Fe, M）29 compounds crystallize in the Th2Ni17-type structure with disordered substitution of the dumbbell Fe-Fe, instead of Nd3（Fe, Ti）29-type structure, so its chemical formula can also be expressed as Er2-n （Fe, M）17＋2n（n = 0.2）. Substitution of M for Fe in the Er3Fe29 compound leads to an increase in the Curie temperature. With the substitution of Co for Fe in the Er3（Fe, M）29（M = Cr, V） compounds, a new phase was found which crystallizes in monoclinic symmetry. The anisotropy of the Er3Fe19.5Co6V3.5 compound at room temperature is of easy-axis type and a spin reorientation transition from the easy-axis type to the easy-plane type anisotropy occurs when temperature decreases to 162K. A first order magnetization process （FOMP） was observed in the HMD magnetization curve of Er3Fe19.5Co6V3.5 at 5K, the critical field of the FOMP was derived to be 3.8T.

关 键 词：稀土金属间化合物 晶体结构 磁晶各向异性 单斜结构 化合物 CO TI MN GA 磁性 单轴各向异性 磁化过程 

分 类 号：O481[理学—固体物理] O482.5[理学—物理]