Charge-Stripe Order and Superconductivity in Ir_1-xPt_xTe₂

A combined resistivity and hard x-ray diffraction study of superconductivity and charge ordering in Ir Ir_1-xPt_xTe₂, as a function of Pt substitution and externally applied hydrostatic pressure, is presented. Experiments are focused on samples near the critical composition x _c  ~ 0.045 where competition and switching between charge order and superconductivity is established. We show that charge order as a function of pressure in Ir_0.95Pt_0.05Te₂ is preempted - and hence triggered - by a structural transition. Charge ordering appears uniaxially along the short crystallographic (1, 0, 1) domain axis with a (1/5, 0, 1/5) modulation. Based on these results we draw a charge-order phase diagram and discuss the relation between stripe ordering and superconductivity.