Magnetoresistance Associated with Antiferromagnetic Interlayer Coupling Spaced by a Semiconductor in Fe<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>/</mml:mi></mml:math>Si Multilayers

Abstract

Multilayer Fe/Si films with constant Fe thickness (2.6 nm) and variable Si thickness are investigated. Negative magnetoresistance is observed and two different temperature dependences are found as a function of Si thickness. For ${t}_{\mathrm{Si}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1.2$ nm, the magnetoresistance decreases with temperature decrease. For ${t}_{\mathrm{Si}}&gt;1.5$ nm, the magnetoresistance increases (weakly) with temperature decrease. The magnetoresistance is attributed to spin-dependent scattering caused by antiferromagnetic layer coupling across a semiconducting spacer: narrow gap iron silicide for thin Si spacer layers and amorphous Si for thicker spacer layers.