Development of Novel Compounds in Co-Sb System by High Pressure Synthesis

High-pressure synthesis has been widely used for exploration of novel materials. In this study, new compounds in a Co-Sb system have been successfully synthesized under GPa-order by using a cubic-anvil-type apparatus. Crystal structures, thermal stabilities, magnetic properties of novel compounds were investigated. Two novel compounds with monoclinic and triclinic structures were synthesized at 1373 K under 6 Gpa. A space group of the monoclinic phase was P2/m (No. 10) and its lattice parameters were a=0.37612(3) nm, b=0.37970(5) nm, c=0.37806(6) nm, α=90.842(8)^°. A crystal structure of new triclinic phase was similar to β-phase ( Co_100-xSb_x, x=48-51). A space group of the triclinic phase was P-1 (No. 2) and its lattice parameter was a=0.40409(4) nm, b=0.40432(4) nm, c=0.52351(4) nm, α=90.163(9)^°, β=90.005(10)^°, γ=120.210(8)^°.