原子取代对SmFe_(12)型化合物磁矩和形成能的影响:第一性原理研究

The effect of multiple atoms substitution on the magnetic moment and formation energy of SmFe_(12) compound:the first principle study

利用第一性原理研究了多个Ti、Co、Ga原子取代SmFe_(12)型化合物中Fe原子后体系磁矩和能量的变化情况。计算结果表明,SmFe_(12)M(M=Ti,Co,Ga)三种体系的形成能均会随取代原子数的增加而下降,表明多个Ti,Co,Ga原子的引入同样有利于降低SmFe_(12)M体系的形成能。另外,Co原子取代后体系的磁矩随着取代原子数的增加先上升后下降,当4个8f晶位的Fe原子被Co原子取代时,体系的磁矩达到最大值。Ti原子和Ga原子取代后体系的磁矩均随取代原子数的增加而单调下降,但是Ga原子取代造成的体系磁矩的下降明显低于Ti原子。因此,Ti、Co、Ga三种原子的优先级应是:Co(取代数为4)>Ga>Ti。

The magnetic moment and formation energy of SmFe_(12) compound substituted by Ti,Co and Ga atoms for Fe atoms were studied by first principle calculation.Calculation results show the formation energy of SmFe_(12)M(M=Ti,Co,Ga)systems decrease with the increase of the number of substituted atoms,which indicates the introduction of multiple Ti,Co,and Ga atoms is also beneficial to reduce the formation energy of SmFe_(12)M systems.In addition,the magnetic moment of system substituted by Co atoms first increases and then decreases with the increase of the number of Co atoms.The magnetic moment of the system reaches its maximum when 4 Fe atoms at 8f site are replaced by Co atoms.The magnetic moment of the system replaced by Ti atoms and Ga atoms decreases monotonically with the increase of the number of substituted atoms,but the decrease of magnetic moment of the system caused by the substitution of Ga atoms is significantly lower than that of Ti atoms.Therefore,the priority of Ti,Co and Ga should be Co(number of substitutions 4)>Ga>Ti.