The first single-crystal preparation, structure determination, and electrical conductivity measurements of a platinum-metal bronze are described. The nickel-platinum bronze Ni0.25Pt3O4 has a cubic structure with a = 5.61 (2) å and crystallizes in space group PmZn or P43w, with two formula units per unit cell. The structure was solved using three-dimensional X-ray data, collected by counter methods. Refinement by full-matrix least-squares methods gave a final R factor of 5.6% on F for the 18 independent reflections. The structure can be described in terms of a filled β-tungsten type, where the “filling” oxygen atoms are in square-planar coordination around the platinum atoms. Nonintersecting chains of Pt atoms run parallel to all three cubic axes. The short Pt-Pt distance of 2.80 (1) A and the electrical resistivity data indicate extensive metallic bonding along the chains. The Ni atoms are situated in channels, each Ni atom being very weakly bonded to eight oxygen atoms.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry