Phase Diagrams of the Reentrant Superconducting Re(1)1?xRe(2)xX (X = Rh4B4) Alloys.Application to Er1?xHoxX, Er1?xGdxX, Er1?xTmxX, HoxLu1?xX and Sm1?xErxX

Abstract

We consider a simplified version of the s–f model, supplemented by the intersite Cooper pair interaction between conduction electrons with opposite spins to investigate the ferromagnetic and superconducting properties of an alloy Re1-x(1)Re(2)xX (Re(1), Re(2) rare earth elements, X = Rh4B4) using the virtual crystal approximation (VCA). For a suitable choice of the model parameters we can reproduce the phase boundaries of the experimentally measured phase diagrams for Er1—xHoxX, Er1—xGdxX, Er1—xTmxX, HoxLu1—xX and Sm1—xErxX alloys.