Superconductivity and Magnetism in a New Class of Heavy-Fermion Materials

Abstract

We report a new family of Ce-based heavy-fermion compounds whose electronic specific heat coefficients range from about 400 to over 700 mJ/mole Ce-K2. Crystal in this family form as CenTmIn3n+2m, where T=Rh or Ir, n=1 or 2, and m=1, with a tetragonal structure that can be viewed as n-layers of CeIn3 units stacked sequentially along the c-axis with intervening m-layers of TIn2. Ambient and high pressure studies show that the quasi-2D layers of CeIn3 produce unconventional superconducting and magnetic ground states. This family should enable new understanding of the relationship between magnetism and superconductivity in heavy-fermion materials and more generally of why heavy-fermion superconductivity prefers to develop in one structure type and not another.