Temperature-dependent interlayer coupling in Fe3 Si/FeSi2 artificial lattices

Fe3Si/FeSi2 artificial lattices, wherein ferromagnetic (F)/antiferromagnetic (AF) interlayer coupling between the Fe3Si layers were induced by controlling the thickness of FeSi2 layers, were prepared on Si(111) substrates by facing targets direct-current sputtering. The interlayer couplings were investigated at different temperatures by measuring the magnetization curves. The AF coupling at room temperature was gradually weakened with a decrease in the temperature, and it finally became ferromagnetic or noncoupled at temperatures lower than 77 K. We consider that the FeSi2 layers act as semiconductors and their change in the electric state for the temperature induces the interlayer coupling switching.