Pressure-tunable superconductivity on cage-like compound Y5Rh6Sn18

Abstract

In this work, we report the pressure-dependent evolution of superconductivity in cage-like compound Y₅Rh₆Sn₁₈ by combining electrical transport measurements, synchrotron x-ray diffraction (XRD) and theoretical computation. The application of external pressure leads to the enhancement of metallic nature in Y₅Rh₆Sn₁₈. There is a noted pressure-tunable superconducting temperature (T_c), which climbs to 3.70 K at 7.4 GPa, and then reverses to 2.37 K at the higher pressure of 30.6 GPa. High-pressure XRD analysis confirm the robustness of Y₅Rh₆Sn₁₈, which exhibits stability without transitioning into other structural phases up to approximately 30 GPa. The ab initio calculations show a significant contribution of Sn s and p electrons as well as Rh and Y d electrons to the total density of states (DOS) near the Fermi level, which supports the multi-band superconductivity of this compound. The enhancement of T_c in Y₅Rh₆Sn₁₈ could be explained by the strengthening of Sn-Sn bonds and the redistribution of Sn atoms in partial density of states (PDOS).