The enhancement of the spin polarization of Co₂ MnSn by Fe doping

We have investigated the effect of Fe doping on the spin polarization of Co₂ Mn_1-x Fe_x Sn (x=0.0, 0.05, 0.1, and 0.2) Heusler alloys by using the point contact Andreev reflection method. The spin polarization increased from 0.6 for x=0.0 to 0.65 for x=0.05. This is attributed to the increase in the spin up states near the Fermi level since Fe is a high valent element compared to Mn. However, with further increase in Fe content, the spin polarization decreased to 0.63 and 0.58 for x=0.1 and 0.2, respectively. Hence, the alloy Co₂ Mn_0.95 Fe_0.05 Sn with low Fe doping (1.25 at. % Fe) could be a potential material for spintronics applications.