Search

The Ce compounds CeCoIn 5 and CeRhIn 5 are ideal model systems to study the competition of antiferromagnetism (AF) and superconductivity (SC). Here we discuss the pressure-temperature and magnetic field phase diagrams of both compounds. In CeRhIn 5 the interesting observation is that in zero magnetic field a coexistence AF + SC phase exist inside the AF phase below the critical pressure p* c ≈ 2 GPa. Above p* c AF is suppressed in zero field but can be re-induced by applying a magnetic field. The collapse of AF under pressure coincides with the abrupt change of the Fermi surface. In CeCoIn 5 a new phase appears at low temperatures and high magnetic field (LTHF) which vanishes at the upper critical field H c2 . In both compounds the paramagnetic pair breaking effect dominates at low temperature. We discuss the evolution of the upper critical field under high pressure of both compounds and propose a simple picture of the glue of reentrant magnetism to the upper critical field in order to explain the interplay of antiferromagnetic order and SC.