Mo${}_6$Ga${}_{31}$ endohedral cluster superconductor

Abstract

Synthesis, crystal and electronic structure, and physical properties of the Mo${}_6$Ga${}_{31}$ endohedral cluster superconductor are reported. The compound has two crystallographic modifications, monoclinic and triclinic, in which the same {Mo${}_{12}$Ga${}_{62}$} building units are perpendicular or codirectional to each other, respectively. Monoclinic and triclinic structures of Mo${}_6$Ga${}_{31}$ possess qualitatively the same electronic density of states showing a high peak at the Fermi level. Both modifications are inherently present in the bulk specimen. Due to the proximity effect, bulk Mo${}_6$Ga${}_{31}$ exhibits single superconducting transition at the critical temperature of 8.2 K in zero magnetic field. The upper critical field, which is 7.8 T at zero temperature, shows clear enhancement with respect to the Werthamer-Helfand-Honenberg prediction. Accordingly, heat capacity measurements indicate strong electron-phonon coupling in the superconducting state with the large ratio of $2\Delta (0)/(k_B{T}_c)=4.5$, where 2$\Delta (0)$ is the full superconducting gap at zero temperature.

References in corpus (6)

• Elaboration of the alpha-Model Derived from the BCS Theory of Superconductivity
• Superconductivity in Rh${}_2$Ga${}_9$ and Ir${}_2$Ga${}_9$ without Inversion Symmetry
• Strong electron-phonon coupling in the intermetallic superconductor Mo${}_8$Ga${}_{41}$
• Two-gap superconductivity in Mo${}_8$Ga${}_{41}$ and its evolution upon the V substitution
• Multi-band superconductivity driven by a site-selective mechanism in Mo${}_8$Ga${}_{41}$
• Three-dimensional Fermi surface and small effective masses in Mo8Ga41

Cited by in corpus (2)

• Superconductivity in Mo${}_4$Ga${}_{20}$As with Endohedral Gallium Clusters
• Conventional s-wave superconductivity and hidden peak effect in single crystals of Mo${}_8$Ga${}_{4}1$ superconductor