SUPERCONDUCTIVITY AND FERROMAGNETISM

In this paper a theory of superconductivity for metals in which there are localized spins is presented. The spins interact with the conduction electrons via an exchange interaction and with one another via a direct Heisenberg interaction, as well as indirectly via the conduction electrons. The spins are treated as classical vectors in a mean-field approximation. The superconducting pair-breaking mechanism is treated in the approximation of Abrikosov and Gor'kov. Complete interplay of magnetization and pair-breaking processes is taken into account. Phase diagrams are presented. A treatment of alloys of two different magnetic ions is included in a simple approximation. All results are in good qualitative agreement with the experiment. © 1979 The American Physical Society.