Superconductivity in Ru-doped CuIr2Te4 telluride chalcogenide

Abstract

Here we report the effect of structural and superconductivity properties on Ru-doped CuIr2Te4 telluride chalcogenide. X-ray diffraction results suggest that CuIr2−xRuxTe4 maintains the disordered trigonal structure with space group P3¯m1 (no. 164) for x ≤ 0.3. The lattice constants, a and c, both decrease with increasing Ru content. Temperature-dependent resistivity, magnetic susceptibility, and specific heat measurements are performed to characterize the superconducting properties systematically. Our results suggest that the optimal doping level for superconductivity in CuIr2−xRuxTe4 is x=0.05, where Tc is 2.79 K with the Sommerfeld constant γ of 11.52mJmol−1K−2, and the specific heat anomaly at the superconducting transition, ΔC/γTc, is approximately 1.51, which is slightly higher than the Bardeen-Cooper-Schrieffer value of 1.43 and demonstrates bulk superconductivity in our CuIr1.95Ru0.05Te4 compound. The values of the lower {Hc1(0)} and upper {Hc2(0)} critical field calculated from isothermal magnetization {M(H)} and magnetotransport {ρ(T,H)} measurements are 0.98 and 2.47 kOe, respectively, signifying that the compound is clearly a type-II superconductor. Finally, a “domelike” shape superconducting transition temperature (Tc) vs x content phase diagram has been established. A low substitution (x=0.03) of Ru for Ir leads to the disappearance of the charge density wave transition, while Tc rises and reaches a maximum value of 2.79 K at x=0.05, followed by a decrease of Tc as x increases. This feature of the competition between the charge density wave we have established and the superconductivity could be caused by tuning the Fermi surface and density of states with Ru chemical doping.

Source-reported materials — not catalogue approval

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