Abstract:
If the condition εσ(p)=ε−σ(−p+nI/vF) for magnetic nesting is fulfilled for the electron dispersion law with spin σ along a certain preferential direction n, ferromagnetism and the inhomogeneous superconducting state can coexist up to a very high magnetization I. This fact was used to explain the coexistence of ferromagnetism and superconductivity for layered cuprates of the RuSr2GdCu2O8 type, which possess a finite, though rather high, critical magnetization, because the conditions for magnetic nesting are fulfilled only approximately.