Chevrel相化合物SnMo6S8超导电性的研究OACHSSCD

Aims:This paper aims to study the superconductivity of Chevrel-phase compound SnMo6S8 by measuring its electrical resistivity and magnetic susceptibility.Methods:SnMo6S8 polycrystalline samples were prepared using the solid-state reaction method.The structure of the samples was characterized by X-ray diffraction.The resistivity and magnetization measurements were carried out using a physical property measurement system(quantum design PPMS-9 T)and a magnetic property measurement system(quantum design MPMS-7T),respectively.The resistivity above the critical temperature Tc was fitted by an empirical formulaρ=ρ0+b×T+d×e-T0/T.The upper and lower critical fields were fitted by the Ginzburg-Landau(GL)formula and an empirical model HTc1=H0c1×[1-(T/Tc)α]β.Results:The space group of SnMo6S8 polycrystals was R-3,with lattice constants a=b=9.26 Å(1 Å=10-10 m),and c=11.34 Å.The superconducting transition temperature Tc=(10.5±0.1)K was obtained through resistivity measurements.The lower critical field was:H0c1=61255 A/m;and the upper critical field was:μ0 H0c2=36.01 T.Conclusions:Through the fitting analysis of the upper critical field,it can be inferred that SnMo6S8 exhibits a second-order phase transition characteristic during the superconducting phase transition and possesses weak spin-orbit coupling.Moreover,the upper critical field of this material exceeds the Pauli limit,which could be due to strong spin-orbit scattering.The fitting of the lower critical field withα=2.23 andβ=0.64 indicates that the superconducting phase transition may be related to the multiband superconductivity mechanism.The aforementioned results provide a new perspective for a deeper understanding of the superconductivity characteristics and the underlying physical mechanisms of SnMo6S8.