Observation of Kondo-like electrical transport in ferromagnetic Fe2Ti1−xMnxSn Heusler alloy

Abstract

We investigate the effect of Mn substitution on the electronic, magnetic, and electrical transport properties of Fe2Ti1−xMnxSn. Spin-polarized density of states calculations using density functional theory indicate a half-metallic ground state in Mn-rich compositions. Localized magnetic moments at Mn sites interact through the conduction electron cloud. Electrical resistivity and magnetotransport measurements show dominant Kondo-like scattering at low temperatures alongside a distinctive linear negative temperature coefficient of resistance at higher temperatures. These findings are further supported by specific heat measurements. Isothermal magnetization as a function of the applied magnetic field identifies the magnetic ground state of Fe2Ti1−xMnxSn compositions as a ferromagnet with a wandering axis that aligns with the direction of the applied field. Temperature-dependent magnetization measurements highlight features indicative of weak anisotropy in the system, while the x-ray diffraction analysis reveals a highly ordered cubic structure with reduced antisite disorder. Investigation of the local crystal structure using x-ray absorption fine structure spectroscopy shows that the random anisotropy arises from local lattice distortions around Mn atoms. These findings shed light on the emergence of a spin-polarized band structure and a unique magnetic ground state in Mn-substituted Fe2Ti1−xMnxSn, offering insights into spintronic materials. ©2025 American Physical Society