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

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