The Abrikosov-Gorkov theory for pairbreaking in superconductors due to a dilute concentration of magnetic impurities is generalized to the case when the magnetic ions are present in a large concentration or on a regular lattice. The case in which the magnetic ions undergo a transition to an antiferromagnetic phase is considered in detail. The physical considerations for increased or decreased pairbreaking over the Abrikosov-Gorkov value due to the increased range of correlations near the antiferromagnetic transition and due to inelastic scattering of electrons off spin waves in the antiferromagnetic phase are discussed in detail. Recent experimental results are considered in terms of the new theory.

• Received 17 November 1980

DOI:https://doi.org/10.1103/PhysRevB.24.137