Superconductivity of new filled skutterudite YFe4P12 prepared at high pressure

A new filled skutterudite YFe4P12 has been prepared at high temperatures and high pressures. The electrical resistivity and do magnetic susceptibility of this compound were measured at low temperatures. The superconductity in YFe4P12 is observed at around 7 K. This phosphide is a new superconductor. The specific heat of YFe4P12 has been studied between 2 and 20 K. The specific heat fitted to the expression C = gammaT + betaT(3), by a least squares analysis, yielded the values gamma = 27.2 mJ mol(-1) K-2 and beta = 0.195 mJ mol(-1) K-4. The Debye temperature (Theta(D)) is found to be 553 K. The electronic density of the states at the Fermi energy for YFe4P12 is 0.45 state eV(-1)/atom.