First-principles study of ultrathin magnetic Mn films on W surfaces.

Abstract

The structural and magnetic properties of static compact thin Mn films deposed on W͑100͒ and W͑110͒ substrates have been investigated in the framework of the density functional theory. In good agreement with experiments, pseudomorphically adsorbed Mn films up to three monolayers ͑ML͒ are found to be stable despite the huge tensile strain induced by the epitaxial conditions. For Mn/ W͑110͒ our results demonstrate a c͑2 ϫ 2͒ in-plane antiferromagnetic order for thicknesses up to 3 ML, with a degenerated layered antiferromagnetism in the ͑110͒ planes for 3 ML thick Mn/ W͑110͒ films. For Mn/ W͑110͒ our calculations predict a ferromagnetic arrangement in 1 and 2 ML thick films stabilized by the hybridization with the substrate, with a transition to an antiferromagnetism layered in ͑100͒ planes at higher thickness. The effects induced by the reduced dimensionality are discussed based on the comparison with bulk Mn and free-standing Mn ML. The magnetic contribution to the adsorption is determined by comparing magnetic and nonmagnetic calculations.

Materials simulations using VASP—a quantum perspective to materials science

“…(i) The formation of high-moment ferromagnetic Mn-films and of antiferromagnetic Fe-layers on W(100) substrates, [32,33] induced by the strong hybridization of the d-band of the magnetic overlayer with the d-band of the substrate. Interestingly, Mn films adsorbed on the more dense W(110) surface display c(2 × 2) in-plane antiferromagnetism (as confirmed by STM studies [34]), and a transition to layered antiferromagnetism for thicker films.…”

Ultrathin Mn layers on Rh(001): Investigations using scanning tunneling microscopy and density functional calculations

“…7 On a W͑001͒ substrate monolayer and bilayer Mn films are ferromagnetic ͑the unusual magnetic configuration being stabilized by the large strains and the strong hybridization with the substrate͒ but already in a 3 ML film in-plane AFM represents the ground state. 24…”

“…The properties of Mn films grown on body-centered tungsten surfaces are determined by the large size mismatch and the strong chemical interaction across the surface. 24,25 Mn/ W͑110͒ films show c͑2 ϫ 2͒ in-plane AFM for up to 3 ML and layered AFM in thicker films. Mn/W͑001͒ films are predicted to be FM up to 2 ML, the ferromagnetism being induced by the strong hybridization between the Mn and W d bands across the interface.…”

Spin-spiral state of a Mn monolayer on W(110) studied by soft x-ray absorption spectroscopy at variable temperatures

“…Ordered Mn monolayer stripes can be prepared on stepped W(110) single crystal substrates by epitaxial step-flow growth [2]. First studies of the magnetic order of Mn/W(110) by spin-polarized STM experiments [3] as well as ab initio calculations [3,4] suggested a collinear antiferromagnetic (AFM) order. Later, field-dependent spin-polarized STM experiments with atomic resolution for a larger field of view revealed a periodic magnetic pattern along the [1 10] direction of W(110), with a wavelength λ of about 12 nm, indicating an AFM cycloidal or helical spin-spiral magnetic ground state [5].…”