Superconducting phase diagram of the filled skuterrudite PrOs4Sb12
  We present new measurements of the specific heat of the heavy fermion superconductor PrOs4Sb12, on a sample which exhibits two sharp distinct anomalies at Tc1= 1.89K and Tc2= 1.72K. They are used to draw a precise magnetic field-temperature superconducting phase diagram of PrOs4Sb12 down to 350 mK.   We discuss the superconducting phase diagram of PrOs4Sb12 and its possible relation with an unconventional superconducting order parameter. We give a detailed analysis of Hc2(T), which shows paramagnetic limitation (a support for even parity pairing) and multiband effects. 
M.-A. Measson, D. Braithwaite, J. Flouquet, G. Seyfarth, J.P. Brison,   E. Lhotel, C. Paulsen, H. Sugawara, H. Sato