Density of electron states of superconductors with transition metal impurities

A study is made of the density of electron states $n(\omega)$ of superconductors with transition metal impurities. Analytic expressions are obtained for the density function $n(\omega)$ with allowance for localized excited states within the energy gap under different assumptions about the parameters $\gamma$ and $\sigma$ of the theory ($\gamma$ determines the position of the local level and $\sigma$ is the pair breaking parameter). A detailed study is made of the case $\gamma=0$, which corresponds to the strongest deviation from Abrikosov and Gov'kov's theory of magnetic impurities. The results are used to calculate the ratio of the rates of relaxation of the nuclear spin in the superconducting and the normal phase for small $\sigma$ and for $\gamma$ differing from zero and unity.