Abstrakt
The electronic structure of the novel intercalation compound Cu0.3ZrTe2 was analyzed using the X-ray photoelectron spectroscopy, resonant photoelectron spectroscopy and DFT calculations. The resonant photoemission enhancement of the valence band features of Cu0.3ZrTe2 at the Zr 3pRIGHTWARDS ARROW4d and Cu 3pRIGHTWARDS ARROW3d photo absorption thresholds was studied.
The tetrahedral coordination of the Cu atoms by the Te atoms was shown to be responsible for the strong chemical bonding of the Cu atoms within the ZrTe2 lattice through the Cu 3d/Te 5p hybridization. These findings were confirmed by theoretical density of states (DOS) calculations performed for CuxZrTe2 (x = 0.25 and 0.5) with the Cu atoms tetrahedrally and octahedrally coordinated by Te atoms.
It was concluded that the substitution of atoms in the CuxTiSe2 system with heavier and polarizable ones (SeRIGHTWARDS ARROWTe, TiRIGHTWARDS ARROWZr), i.e. an increase in the lattice polarizability, destabilizes the octahedral coordination of the Cu atoms by the Se/Te ones. This limits the stability of the phases characterized by quantum states with a charge density wave and superconductivity.