Theoretical study of phase diagrams for reentrant superconducting Er1-xHoxX, Er1-xGdxX, Er1-xTmxX, HoxLu1-xX, and Sm1-xErxX (X = Rh4B4) alloys

Abstract

We consider a simplified version of the s— f model, supplemented by the intersite Cooper pairs interaction between conduction electrons with opposite spins to investigate ferromagnetic and superconducting properties of an alloy Re (1) 1-xRex(2)Χ (Re(1)'(2) — rare earth elements, Χ = Rh4Β4) using the virtual crystal approximation. For a suitable choice of the model parameters we can reproduce the phase boundaries of the experimentally measured phase diagrams for Εr1-xΗoxX, Er1xGdxΧ, Εr1xTmxΧ, Ηο Lu1xΧ, and Sm1-xErxX alloys.