Heavy fermion superconductivity in the transuranium neptunium compound

Aoki, Dai*; Haga, Yoshinori   ; Onuki, Yoshichika

Several unconventional superconductors with non-s wave symmetry are known in the rare earth and uranium compounds with f-electrons. However, no superconductivity has been reported in the transuranium neptunium compounds in the past. Here we report the first observation of the superconductivity in the new compound NpPdAl. Novel superconducting phenomena, such as high superconducting transition temperature, strong paramagnetic effect and first-order phase transition at the upper critical field, were found in NpPdAl.