High-pressure synthesis of a new copper thioborate, CuBS_2

摘要

A new copper thioborate, CuBS_2, was synthesized at high-pressure/temperature condition of 3 GPa and 700-900℃. The crystal structure was refined by the Rietveld analysis of the powder X-ray diffraction data. The compound crystallizes into a tetragonal unit cell (a=0.5044(1) nm, c=0.8947(2) nm, space group: I-42d), isostructural with CuMS_2 chalcopyrite compounds (M: Al, Ga, and In). The compound is the first representative of the chalcopyrite-type family consisting of BS_4-tetrahedra. From the UV-Vis diffuse reflectance spectrum, the optical band gap of CuBS_2 was estimated to be E_g = 3.61 eV.