Emergence of superconductivity near the structural phase boundary in Pt-doped IrTe₂ single crystals

Single crystals of Ir_1-xPt_xTe₂ were synthesized and characterized. The low-temperature monoclinic phase of IrTe₂ is suppressed and disappears with slight Pt doping. The breaking of the Ir-Ir bonds, a characteristic of the low-temperature monoclinic phase in pure IrTe₂, is accompanied by the emergence of a superconducting phase. The Pt-content dependence of the structural phase-transition temperature and the superconducting transition temperature in single crystals adequately reproduced those in polycrystals. We also found a broad hysteresis of magnetization throughout a wide range of temperatures in pure IrTe₂.