An All-Epitaxial Fe3Si/FeSi/Co2FeSi Trilayer Grown by Room-Temperature Molecular Beam Epitaxy

We present a heat-treatment-free fabrication technique for pseudo current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) structures with a highly spin-polarized Co-based Heusler-compound electrode. Room-temperature molecular beam epitaxy enables an all-epitaxial Heusler compound/metallic spacer/Heusler compound, i.e., Fe
₃
Si/FeSi/Co
₂
FeSi, trilayer structure. Since each layer includes ideally ordered structures, the magnetization reversal process of the trilayer is changed from two-step switching to one-step switching upon cooling through the paramagnetic-ferromagnetic transition of the ordered FeSi spacer layer. This paper will open a way for high-performance CPP-GMR devices with Co-based Heusler compounds.