DEPENDENCE OF TC ON NORMAL AND MAGNETIC-IMPURITIES IN THE HOLE MECHANISM OF SUPERCONDUCTIVITY

The influence of impurities on the superconducting transition temperature including effects of the finite bandwidth is investigated. The attractive Hubbard model is treated first, where it is found that normal impurities are pair breaking for narrow bands. Nonetheless, magnetic impurities are almost always significantly more pair breaking. Then we investigate a recently proposed model for superconductivity in the high-T(c) oxides, the hole mechanism. It is found that for the relevant parameter regime of the high-T(c) oxides, normal and magnetic impurities are equally pair breaking. This behavior is in qualitative agreement with transition-metal-doping expeirments.