Magneto-transport and microstructure of Co₂Fe(Ga _0.5Ge_0.5)/Cu lateral spin valves prepared by top-down microfabrication process

Heusler alloy-based lateral spin valves with ohmic contacts are prepared for the Co₂Fe(Ga_0.5Ge_0.5)/Cu system by means of the top-down microfabrication process. The magneto-transport and microstructure are characterized to investigate the influence of the microfabrication route on the spin dependent transport of lateral spin valves systematically. A large non-local spin signal (?R_S) of 17.3mΩ is observed at room temperature, which is attributed to the highly spin-polarized Co ₂Fe(Ga_0.5Ge_0.5) ferromagnet and the clean Co₂Fe(Ga_0.5Ge_0.5)/Cu interfaces confirmed by transmission electron microscopy. Based on the general expression of one-dimensional spin diffusion model, we discuss the importance of interfacial spin polarization in Heusler alloy-based lateral spin valves.