Layer-resolved magnetic exchange interactions of surfaces of late 3d elements : Effects of electronic correlations

• We present the results of an ab initio study of the magnetic properties of Fe, Co, and Ni surfaces. In particular, we discuss their electronic structure and magnetic exchange interactions (J(ij)), as obtained bymeans of a combination of density functional theory and dynamical mean-field theory. All studied systems have a pronounced tendency to ferromagnetism both for bulk and surface atoms. The presence of narrowband surface states is shown to enhance the magnetic moment as well as the exchange couplings. The most interesting results were obtained for the Fe surface where the atoms have a tendency to couple antiferromagnetically with each other. This interaction is relatively small when compared to interlayer ferromagnetic interaction, and it depends strongly on the lattice parameter. Local correlation effects are shown to lead to strong changes of the overall shape of the spectral functions. However, they seem not to play a decisive role in the overall picture of magnetic couplings studied here. We have also investigated the influence of correlations on the spin and orbital moments of bulklike and surface atoms. We found that dynamical correlations in general lead to enhanced values of the orbital moment.

Ämnesord

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Nyckelord

Mean-Field Theory

1st-Principles Calculations

Orbital Magnetism

Transition-Metals

Ni(001) Surface

Nickel Metal

Spin-Waves

Systems

Fe

Co

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