Large Interface Spin-Asymmetry and Magnetoresistance in Fully Epitaxial Co₂MnSi/Ag/Co₂MnSi Current-Perpendicular-to-Plane Magnetoresistive Devices

Abstract

Current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) characteristics were investigated in a Co2MnSi (CMS)/Ag/CMS fully epitaxial device and compared to those in a CMS/Cr/CMS device systematically. Reflection high-energy electron diffraction and transmission electron microscopy images showed the two samples had no remarkable differences and little interdiffusion. The large spin-asymmetry of electron scattering was found at the CMS/Ag inteface compared with that at the CMS/Cr interface. Finally, the largest magneto-resistance (MR) ratio of 28.8% was observed at room temperature in the CMS/Ag/CMS CPP-GMR device.