Magnetic structure map for face-centered tetragonal iron: Appearance of a collinear spin structure

Article

关键词: AUGMENTED-WAVE METHOD;    BRILLOUIN-ZONE INTEGRATIONS;    EPITAXIAL-FILMS;    FCC IRON;    DENSITY-WAVE;    GAMMA-IRON;    FE FILMS;    CU(100);    SURFACE;    ALLOYS;   

DOI  :  10.1103/PhysRevB.90.014432

来源: SCIE

【 摘 要 】

For fcc and tetragonal distorted fct iron a large number of magnetic configurations as a function of crystal structural parameters were studied by means of density functional theory concepts. The stability of magnetic structures was defined by the magnetic reorientation energy Delta E-reor(i) as the difference of the total energy of configuration i and that of the fcc ferromagnetic state. The cluster expansion technique was applied to six volumes deriving Delta E-reor for more than 90 000 collinear spin structures at each volume. Structures with low Delta E-reor were tetragonally distorted according to a two-dimensional mesh defined by volume per atom V and c/a ratio. At each mesh point Delta E-reor for all collinear structures were compared to results for spin spirals (SSs) which were calculated on a grid of propagation directions, and then the lowest Delta E-reor defined the magnetic structure map. Three local minima were identified and for each of the minima SSs were calculated on a fine grid of propagation vectors. At the minimum with V = 10.6 angstrom(3) and 0.94 <= c/a <= 1.01 a hitherto unknown simple collinear spin structure with four atoms per fct unit cell was the most stable one. It consists of two atoms with antiferromagnetically ordered local moments of +/- 1.8 mu(B) and of two atoms with zero local moment.

【 授权许可】

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