Strain-modulated spin Hall magnetoresistance in YIG/Pt heterojunctions

This paper reports that the substrate-induced strain effect can be utilized to control spin Hall magnetoresistance (SMR) of YIG/Pt heterojunctions. The YIG films with in-plane compressive strain and tensile strain are respectively prepared on GGG and GSGG substrates by pulsed-laser deposition. The ratio of SMR of YIG/Pt heterojunctions with YIG under the in-plane tensile strain state is 1.6 time larger than that of YIG with the out-of-plane compressive strain state. The spin mixing conductance of YIG/Pt interface increases with the substrate-induced in-plane tensile strain on YIG. The increase of roughness and the reduction of ratio of Fe3+/Fe2+ for YIG surface is responsible for this modulation. This finding provides an interesting prospect for control of SMR by substrate-induced strain effect.