Modification of the spin structure of chromium by an interface effect inCr(011)∕Snmultilayers

Abstract

We have studied the magnetic structure of Cr layers in $\mathrm{Cr}(011)∕\mathrm{Sn}$ multilayers, where monatomic Sn layers are periodically inserted along the bcc [011] direction. This direction is not parallel to the wave vector $\mathbit{Q}$ of an incommensurate spin-density wave (ISDW) in bulk Cr. In a $[\mathrm{Cr}(80\phantom{\rule{0.3em}{0ex}}\mathrm{\AA{}})∕\mathrm{Sn}(2\phantom{\rule{0.3em}{0ex}}\mathrm{\AA{}})]$ multilayer, only a commensurate antiferromagnetic (CAF) structure appears at $7\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. In a multilayer with $160\text{\ensuremath{-}}\mathrm{\AA{}}$-thick Cr layers, on the other hand, the CAF and ISDW with $\mathbit{Q}$ parallel to the [010] and [001] directions coexist at low temperatures. These results can be explained by the competition between the nesting at the Fermi surface, which tends to form ISDW's with $\mathbit{Q}$ parallel to the ⟨100⟩ directions, and an interface effect in the (011) interfaces, which tends to enhance the magnetic moments of Cr at the interfaces.