Electronic structure of Co2-xPdxTiSn alloys

The electronic structure of the Co2-xPdxTiSn Heusler alloys have been studied by X-ray photoemission spectroscopy (XPS). Co2TiSn and Pd2TiSn ordered alloys crystallize in the L21-type structure. The X-ray diffraction studies showed that there is a solid solubility within the L21-type structure for all the x values. XPS valence band spectra can be compared with ab initio electronic structure calculations using the linearized muffin-tin orbital (LMTO) method. We have found the gap in the bands between the Sn s-states and the d-states of the other elements. The Ti d-states are located near to the Fermi level and are strongly hybridized with the Pd or Co d-states. Careful analysis of the valence bands, calculated and experimentally obtained, suggests an atomic disorder in the investigated alloys. (orig.)