An unusual Cu/Te hybridization in the Cu0.3ZrTe2 intercalation compound

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 3p -> 4d and Cu 3p -> 3d 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) cal-culations 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 (Se.Te, Ti.Zr), 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.

Automated summary

The electronic structure of the novel intercalation compound Cu0.3ZrTe2 was analyzed using various experimental techniques and theoretical calculations. It was found that the tetrahedral coordination of Cu atoms by Te atoms leads to strong chemical bonding within the ZrTe2 lattice. The stability of the phases characterized by quantum states with a charge density wave and superconductivity is influenced by the coordination of Cu atoms by different atoms.