Fermi level tuning of highly spin-polarized complex Heusler alloys via materials genome

Heusler alloys are the largest family of half-metals (100{\%} spin polarized at the Fermi level) and most promising for spintronic device applications. Many half-metallic full-Huesler alloys are predicted from \textit{ab-initio} calculations, but may or may not be experimentally realizable. Here, we present a novel strategy to utilize these predicted materials to tune the Fermi level of well-known, highly spin-polarized Heusler alloys. We start with the test sample of [Co$_{2}$MnSi]$_{\mathrm{1-x}}$[Co$_{2}$CrGe]$_{\mathrm{x}}$, and, by controlling the ratio of these materials, we were able to shift the Fermi level of Co$_{2}$MnSi. Experimentally, we study the structural and magnetic properties of such Heusler alloys by room temperature X-ray diffraction (XRD) and taking magnetization measurements; It was found that these complex combinations of materials are single phase even though some components (Co$_{2}$CrGe for example) might not be stable in bulk form alone.