Fully epitaxial current-perpendicular-to-plane giant magnetoresistance (MR) devices with half-metallic Co2 MnSi (CMS) electrodes and a Ag spacer were fabricated to investigate the relationship between the chemical ordering in CMS and its MR properties, including bulk and interface spin-asymmetry coefficients β and γ. CMS/Ag/CMS annealed at 550°C shows the largest MR ratio: 36.4% and 67.2% at RT and 110 K, respectively. An analysis based on Valet-Fert's model reveals large spin asymmetry (γ>0.8) at the CMS/Ag interface, which contributes predominantly to the large MR ratio observed. First-principles ballistic conductance calculations for (001)-CMS/Ag/CMS predict a high majority-spin electron conductance, which could be the origin of the large γ observed in this study.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2010 Sep 28|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics