Structural and magnetic properties of FeCoMnCrSi multi-principal alloy

In this study, the magnetic properties of Fe39.8Co19.92Mn20.52Cr14.77Si5 multi-principal element alloy in both bulk and thin films were studied. X-ray diffraction measurements show coexisting face centered cubic (FCC) and hexagonal close packed phases in the bulk and the 500 nm thin films, while only FCC phase is observed in the 65 nm thin film. A four orders of magnitude increase in the magnetic moment is observed for 65 nm thin film compared with the bulk sample. Evolution of magnetization as a function of temperature and applied magnetic field shows multiple magnetic transitions. A paramagnetic to spin glass transition is detected at T-S similar to 390 K for all samples. Further cooling results in a spin glass to ferromagnetic (FM) transition, and the transition temperature, T-F, is dependent on the film thickness. Higher saturation magnetization and transition temperature observed for the thin film samples indicate the stabilization of FM ordering due to thickness confinement.