Electronic structure and symmetry of valence states of epitaxial NiTiSn and NiZr0.5Hf0.5Sn thin films by hard x-ray photoelectron spectroscopy

The electronic band structure of thin films and superlattices made of Heusler compounds with NiTiSn and NiZr0.5Hf0.5Sn composition was studied by means of polarization dependent hard x-ray photoelectron spectroscopy. The linear dichroism allowed to distinguish the symmetry of the valence states of the different types of layered structures. The films exhibit a larger amount of "in-gap" states compared to bulk samples. It is shown that the films and superlattices grown with NiTiSn as starting layer exhibit an electronic structure close to bulk materials.