Probing half-metallicity in Mn2CoSi/Si(100) thin film structures using electrical transport measurements towards spintronic applications

Abstract

The structural, magnetic, and electronic transport properties of Mn₂CoSi (MCS) thin film have been studied to explore the possibility of half-metallicity of MCS Heusler alloy (HA) in thin film form. Grazing incidence X-ray diffraction (GIXRD) data indicated the presence of the rhombohedral crystal structure with a space group of R $\bar{3}$ (148). Spectrum fitting of X-ray reflectivity (XRR) suggests the deposited film has smooth surface with uniform density. Magnetic analysis reveals the ferrimagnetic nature of the film with a transition temperature well above the room temperature. Electric transport study of MCS thin film indicates the non-metallic behavior (< 250 K) and metallic behavior (> 250 K) in different temperature regimes. The persistence of half-metallicity across the entire temperature range is supported by the presence of T^7/2 terms in the resistivity data due to two-magnon scattering. Arrhenius equation fitting of the electrical resistivity data in the non-metallic regime results the activation energy of 4.98 meV. At room temperature, the electrical resistivity is 1.372 mΩ-cm which is consistent with the values reported previously for other well-known half-metallic HAs. The observed results of HA in thin film form seems encouraging to us which could find its applications as a magnetic electrode for future spintronics.