Electronic structure and charge dynamics of the Heusler alloy Fe2TiSn probed by infrared and optical spectroscopy -: art. no. 075122

We report on the electrodynamics of a Heusler alloy Fe2TiSn probed over 4 decades in energy: from the far infrared to the ultraviolet. Our results do not support the suggestion of Kondo-lattice behavior inferred from specific-heat measurements. Instead, we find a conventional Drude-like response of free carriers, with two additional absorption bands centered at around 0.1 and 0.87 eV. The latter feature can be interpreted as excitations across a pseudogap, in accord with band-structure calculations.