• Perez, Christopher J.
• Walker, David
• Emge, Thomas J.
• Skaggs, Callista M.
• Greenblatt, Martha
• Kauzlarich, Susan M.
• Pak, Chongin
• Hadermann, Joke
• Frank, Corey E.
• Kang, Chang-Jong
• Tan, Xiaoyan
• Lapidus, Saul H.
• Kotliar, Gabriel

Abstract

The mineral Zlatogorite, CuNiSb2, was synthesized in the laboratory for the first time by annealing elements at ambient pressure (CuNiSb2-AP). Rietveld refinement of synchrotron powder X-ray diffraction data indicates that CuNiSb2-AP crystallizes in the NiAs-derived structure (P (3) over bar m1, #164) with Cu and Ni ordering. The structure consists of alternate NiSb6 and CuSb6 octahedral layers via face-sharing. The formation of such structure instead of metal disordered NiAs-type structure (P6(3)/mmc, #194) is validated by the lower energy of the ordered phase by first-principle calculations. Interatomic crystal orbital Hamilton population, electron localization function, and charge density analysis reveal strong Ni-Sb, Cu-Sb, and Cu-Ni bonding and long weak Sb-Sb interactions in CuNiSb2-AP. The magnetic measurement indicates that CuNiSb2-AP is Pauli paramagnetic. First-principle calculations and experimental electrical resistivity measurements reveal that CuNiSb2-AP is a metal. The low Seebeck coefficient and large thermal conductivity suggest that CuNiSb2 is not a potential thermoelectric material. Single crystals were grown by chemical vapor transport. The high pressure sample (CuNiSb2-8 GPa) was prepared by pressing CuNiSb2-AP at 700 degrees C and 8 GPa. However, the structures of single crystal and CuNiSb2-8 GPa are best fit with a disordered metal structure in the P (3) over bar m1 space group, corroborated by transmission electron microscopy.

Topics

• density
• impedance spectroscopy
• mineral
• single crystal
• resistivity
• powder X-ray diffraction
• transmission electron microscopy
• annealing
• thermal conductivity
• metal-matrix composite
• space group
• ordered phase