The metal-rich palladium chalcogenides Pd2MCh2 (M=Fe, Co, Ni; Ch=Se, Te): Crystal structure and topology of the electron density

Electrical properties of ternary metal-rich telluride Pd2NiTe2

“…Figure 6 shows the total density of states (DOS) and the partial DOS of each atom of Pd2NiTe2. The features of the total DOS and the partial DOS of Pd, Ni, and Te are very similar to those of the total DOS and partial DOS of Pd, Co, and Se for Pd2CoSe2, 13) respectively. However, the Fermi level shifts toward higher energy only for one electron by substitution of cobalt to nickel.…”

“…13) Figure 1 shows the observed and calculated XRD profiles for Pd2NiTe2. The calculated X-ray diffraction profile was in good agreement with the observed one (Rwp = 10.5%, RI = 3.4%).…”

“…Pocha et al reported that the Co-Co distance for the isostructural Pd2CoSe2 is in agreement with fcc cobalt metal and confirmed the strong metal-metal bonding from the electronic-structure calculation. 13) Due to the deference in the metal-metal bondings between Pd2CoSe2 and Pd2NiTe2, the longer Ni-Ni distance should be derived from the substitution of selenium to larger tellurium and is expected that the metal-metal bonding becomes weaker. In addition, a Pd-Pd interatomic distance (2.900(2) Å) also exists in Pd2NiTe2 and is slightly longer than that (2.75 Å) of fcc palladium, which might indicate metal-metal bondings.…”

“…13) These chalcogenides crystallize in a K2ZnO2-type structure with space group Ibam. In this structure, the M ions are tetrahedrally coordinated by chalcogenide ions and the MCh4 share edges forming an infinite 1D chain parallel to the caxis.…”

“…The electronic structure calculation of Pd2CoSe2 indicates that this compound has the nature of chemical bonding in the electron-rich intermetallic compounds. 13) Although such a chalcogenide is expected to show interesting electrical properties like CDW, its electrical properties have not been investigated yet.…”