Superconductivity in ternary pyrite-type compound IrBi${}_{1-x}$Te${}_{1+x}$ ($x\approx 0.2$) at ambient and high pressure

We report superconductivity in the ternary compound IrBi${}_{0.8}$Te${}_{1.2}$ with critical temperature 1.7 K. The replacement of Bi by Te leads to the metallic conductivity in contrast to the semiconducting parent compound IrBiTe. The superconductivity can be further enhanced by application of external pressure. $T_c$ demonstrates dome-shaped dependence on pressure with a maximum value of 2.6 K at 26.5 GPa. Pressure effects on electronic properties and lattice dynamic of IrBi${}_{0.8}$Te${}_{1.2}$ were studied by pressure dependent electrical resistivity, Hall effect and Raman spectroscopy measurements.