IS LA3NI A NEW UNCONVENTIONAL SUPERCONDUCTOR

We find that La3Ni is a type-II superconductor with a Ginzburg-Landau parameter, kappa=49. The temperature dependence of the specific heat r eveals two peaks, one of which appears in the superconducting phase an d is ascribed to the symmetry change of the superconducting order para meter. We observe nearly T3 power law dependence of the specific heat, implying that the superconducting energy gap function has nodes on po ints. The lower critical magnetic field H(cl) in the lower temperature phase is larger than that in the higher temperature phase.