Crystal structure, superconductivity and magnetic properties of the   superconducting ferromagnets Gd1.4-xDyxCe0.6Sr2RuCu2O10 (x=0 - 0.6)
  The structural, electrical and magnetic properties of the superconducting ferromagnets, Gd1.4-xDyxCe0.6Sr2RuCu2O10 (x=0-0.6) are systematically investigated as a function of Dy doping and temperature. These compounds are characterised by high temperature superconductivity (Tc ranging from 20-40 K depending upon the Dy content) coexisting with weak ferromagnetism with two magnetic transitions (TM2 ranging from 95-106 K and TM1 around 120 K). Doping with Dy gives no significant structural changes except for a minor change in the c/a ratio. However the superconducting transition temperature is significantly suppressed and magnetic ordering temperature enhanced on Dy doping. These effects are described and discussed. 
S. Kalavathi, J. Janaki, G.V.N. Rao, V. Sankara Sastry and Y.   Hariharan