过渡金属掺杂对γ′-Fe_4N的热稳定性和磁性的影响

Effect of Doped Transition Metal on Thermal Stability and Magnetic Properties of γ′-Fe_4N

利用第一性原理密度泛函理论,对不同过渡金属M(M=Mn,Co,Ni)掺杂γ′-Fe4N的结构进行焓值计算.结果表明:以MnFe3N/Fe2,CoFe3N/Fe2和NiFe3N/Fe1为掺杂结构的能量最稳定,且均呈铁磁性;掺杂过渡金属元素的原子序数越小,体系的能量越低,材料的结构越稳定;随着压强的增加,掺杂元素替代面心不等价Fe位可有效减小压强对材料磁性的影响,使材料在更大压强区间内保持强铁磁性,衰减速率相对较低.

We calculated the enthalpies of γ′-Fe4 N doped by different transition metals M （M= Mn, Co,Ni） by using first principles density functional theory. The results show that the energy of MnFe3N/Fe2.,CoFe3N/Fe2 and NiFe3N/Fel are the most stable structures, and all of them are ferromagnetic materials. The energy of the system decreases with the decrease of the atomic numbers of the doped transition metal elements, and the structures of the material are more stable. With the increase of pressure, the substitution of doped elements for face-centered non equivalent Fe positions can effectively reduce the effect of pressure on the magnetic properties of the material, the material maintains strong ferromagnetism in a larger pressure range, and the decay rate is relatively low.