The Fermi level (EF) control of half-metallic Heusler alloy Co2 MnSi by Al-doping was challenged in magnetic tunnel junctions with a Co2 MnAlx Si1-x (CMAS) electrode. The observed bias voltage dependence on tunneling conductance (G-V curves) clearly shows a shift in EF toward the center of the half-metallic gap with x, which showed excellent agreement with our first-principles calculations. However, the ratio of tunnel magnetoresistance (TMR) at 10 K to that at room temperature does not exhibit a remarkable change with x. The weak exchange energy at the CMAS interface may be the origin for the large temperature dependence of the TMR ratio.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2010 Apr 22|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics