Phase Separation, Magnetism and Superconductivity in Rutheno-Cuprates
  The properties of the superconducting ferromagnets RuSr2(Gd/Eu)Cu2O8 and RuSr2(Ln/Ce)2Cu2O10 are reviewed. The problem of coexistence and competition between magnetic and superconducting states is discussed. A model of phase separation into ferromagnetic and anti-ferromagnetic structures is proposed. 
B. Lorenz, Y. Y. Xue, and C. W. Chu