Cobalt antimonides

The phosphides, arsenides, and antimonides of the other metals are usually dark-coloured substances, with more or less metallic lustre, and therefore conductors of electricity. Some of them occur native for example, smaltine, CoAs2, a common ore of cobalt, forming silver-white crystals copper-nickel, NiAs, red lustrous crystals, and one of the chief nickel ores speiss, a deposit formed in the pots in which smaltine and copper-nickel are fused with potassium carbonate and silica, in the preparation of smalt, a blue glass containing cobalt its formula appears to be Ni8As2. Mispickel, or arsenical pyrites, is a white lustrous substance, of the formula FeSAs. 

Cobalt Antunonide or Cobalt Mono-antimonide, CoSb, may be obtained by direct union of antimony and cobalt,1 or by heating cobalt in antimony trichloride vapour at 700-1200° C.2 It melts at 1191° C., and has a density of 8-12 at 0° C. In air it undergoes slight oxidation, burns readily in oxygen, and dissolves in hot, concentrated sulphuric acid. 

Cobalt Di antimonide, CoSb2,3 has also been prepared. It melts with decomposition at 879-5° C. density 7-76 at 0° C. In its chemical properties it resembles the mono-antimonide. 

T. Rosenqvist, Magnetic and Crystallographic Studies of the Higher Antimonides of Iron, Cobalt, and Nickel, Trondheim (1953). 

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