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arXiv · 2012.01729

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

J. Honolka·S. Krotzky·M. Menzel·T. Herden·V. Sessi·H. Ebert·J. Minar·K. von Bergmann·R. Wiesendanger·O. Sipr
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Abstract

The noncollinear magnetic state of epitaxial Mn monolayers on tungsten (110) crystal surfaces is investigated by means of soft x-ray absorption spectroscopy, to complement earlier spin-polarized STM experiments. X-ray absorption spectra (XAS), x-ray linear dichroism (XLD) and x-ray magnetic circular dichroism (XMCD) Mn L23-edge spectra were measured in the temperature range from 8 to 300 K and compared to results of fully-relativistic ab initio calculations. We show that antiferromagnetic (AFM) helical and cycloidal spirals give rise to significantly different Mn L23-edge XLD signals, enabling thus to distinguish between them. It follows from our results that the magnetic ground state of a Mn monolayer on W(110) is an AFM cycloidal spin spiral. Based on temperature-dependent XAS, XLD and field-induced XMCD spectra we deduce that magnetic properties of the Mn monolayer on W(110) vary with temperature, but this variation lacks a clear indication of a phase transition in the investigated temperature range up to 300 K - even though a crossover exists around 170 K in the temperature dependence of XAS branching ratios and in XLD profiles.

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J. Honolka, S. Krotzky, M. Menzel, T. Herden, V. Sessi, H. Ebert, J. Minar, K. von Bergmann, R. Wiesendanger, O. Sipr. 2020-12-03. Spin-spiral state of a Mn monolayer on W(110) studied by soft x-ray absorption spectroscopy at variable temperatures. https://doi.org/10.1103/physrevb.103.174419

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