Superconductivity at 5.4 K in $\beta$-Bi$_2$Pd
  We investigate bulk superconductivity in a high-quality single crystal of Bi$_2$Pd ($\beta$-Bi$_2$Pd, space group; I4/mmm) at temperatures less than 5.4 K by exploring its electrical resistivity, magnetic susceptibility, and specific heat. The temperature dependence of the electrical resistivity shows convex-upward behaviors at temperatures greater than 40-50 K, which can be explained by a parallel-resistor model. In addition, we demonstrate that this material is a multiple-band/multiple-gap superconductor based on the temperature dependences of the specific heat and the upper critical field. 
Yoshinori Imai, Fuyuki Nabeshima, Taiki Yoshinaka, Kosuke Miyatani,   Ryusuke Kondo, Seiki Komiya, Ichiro Tsukada, Atsutaka ...
cond-mat.supr-con