基于朗道二级相变理论的铁单晶磁结构分析

Analysis on Magnetic Structure of Single-Crystal Iron by Landau Theory of Second-Order Phase Transition

利用朗道二级相变理论以及磁点群理论对于4种单晶铁,也就是阿尔法-铁、德尔塔-铁、伽马-铁以及伊普西龙-铁的磁结构进行了分析。其中,着重利用朗道二级相变理论中实现二级相变的条件和Birman的群选择定则来分析一定晶体结构的铁单晶如果发生顺磁铁磁相变后可能具有的空间对称性,进而得到铁单晶可能具有的磁结构。同时,得到的结论与之前文献报道中的结果进行了比较,发现符合得很好。

The magnetic structures of four kinds of single-crystal iron,i.e.,α-Fe,δ-Fe,γ-Fe,and ε-Fe,are analyzed by Landau theory of second-order phase transition and magnetic point group theory.The possible spatial symmetry of the single-crystal iron with a crystal structure is investigated if the paramagneticferromagnetic transition arises,using the condition of realizing the second-order transition of the Landau theory and the Birman＇ s group-theoretical selection rules.The possible magnetic structure of the singlecrystal iron can be obtained.Compared with the existing experimental results it is found that experimental results are in good agreement with our theoretical analyses.