We performed a comprehensive study of the vanadium-based anti-post-perovskite compounds V,inf>3XC (X = Ge, P, As) and V3XN (X = Ga, Ge, P, As). It was clarified that V3PN and V3AsN exhibit superconducting transitions at 4.2 and 2.6 K, respectively, whereas the other compounds not show superconducting transition above 1.8 K. We further investigated substitution effects on superconductivity in V3PN, and found that the superconducting transition temperature (Tc) shows a dome-shaped curve with maximum Tc values of 5.45K at x = 0.05 and 5.82K at x = 0.10 for V3P1-xAsxN and V3P1-xSbxN, respectively. In these optimal compositions, clear implications of the phonon softening and the enhanced electron-phonon coupling were revealed by the analysis of specific heat data. Our findings showed that structural instability is one of the important factors for tuning superconducting properties in vanadium-based superconductors with an anti-post-perovskite structure.
ASJC Scopus subject areas
- Physics and Astronomy(all)