Specific-Heat Anomalies at the Lower Critical Temperature in Reentrant Ferromagnetic Superconductors

Abstract
A spike-shaped heat-capacity anomaly has been identified at the lower superconducting-to-normal transition temperature Tc2 of the magnetic superconducting system (Er1xHox)-Rh4 B4. This anomaly can be distinguished from the feature due to long-range magnetic ordering and indicates that the transition at Tc2 is thermodynamically of first order.