A New Heavy-Fermion Superconductor CeIrIn5: Relative of the Cuprates?
  CeIrIn5 is a member of a new family of heavy-fermion compounds and has a Sommerfeld specific heat coefficient of 720 mJ/mol-K2. It exhibits a bulk, thermodynamic transition to a superconducting state at Tc=0.40 K, below which the specific heat decreases as T2 to a small residual T-linear value. Surprisingly, the electrical resistivity drops below instrumental resolution at a much higher temperature T0=1.2 K. These behaviors are highly reproducible and field-dependent studies indicate that T0 and Tc arise from the same underlying electronic structure. The layered crystal structure of CeIrIn5 suggests a possible analogy to the cuprates in which spin/charge pair correlations develop well above Tc. 
C. Petrovic, R. Movshovich, M. Jaime, P. G. Pagliuso, M. F. Hundley,   J. L. Sarrao, Z. Fisk, and J. D. Thompson