Large spin accumulation signal in half-metallic Co2MnSi based lateral spin valve devices

Abstract

Here, we use half-metallic Co2MnSi (CMS) ferromagnets to prepare CMS/Ag non-local lateral spin valve devices. By optimizing the structural property of CMS wires and the interface quality, device structure of CMS/Ag spin valves, large spin resistance about 4.2 mΩ can be observed clearly at room temperature when the gap length of two CMS wires is 200 nm. By fitting the spin accumulation signals, we obtained that the spin diffusion length for Ag wire is 290 nm and the spin polarization for CMS wires is 74%. These results indicate that half-metallic ferromagnetic materials can be used in semiconductor-based spin devices.