arXiv subjects
Publications and source records attributed to Le-Wei Chen.
The Ge-doped GaNb4Se8 polycrystalline samples were synthesized by solid-state reaction method. Zero resistance transitions were observed in one batch of samples with the highest onset superconducting Tc at 45 K. This discovery may demonstrate a new class of Nb-based high-Tc superconductors arising from doped Mott insulators.
We report the discovery and detailed investigation of superconductivity in Mo$_4$Ga$_{20}$As. Mo$_4$Ga$_{20}$As crystallizes in the space group of $I4/m$ (No. 87), with lattice parameters $a$ = 12.86352 Åand $c$ = 5.30031 Å. The resistivity, magnetization, and specific heat data reveal Mo$_4$Ga$_{20}$As to be a type-II superconductor with $T_c$ = 5.6 K. The upper and lower critical fields are estimated to be 2.78 T and 22.0 mT, respectively. In addition, electron-phonon coupling in Mo$_4$Ga$_{20}$As is possibly stronger than the BCS weak-coupling limit. First-principles calculations suggest the Fermi level being dominated by the Mo-4$d$ and Ga-4$p$ orbitals.