Mass enhancement in strongly paramagnetic transition metals

The mass enhancement of strongly paramagnetic transition metals has been calculated using a model in which the $d$ electrons interact via a short-range repulsive interaction. A novel feature of this calculation is that the finite width of the $d$ band has been explicitly included. For a given exchange enhancement of the uniform susceptibility, the finite $d$-band width causes a sharp reduction in the mass enhancement due to electron-paramagnon interactions, especially when the Fermi level is near the top of the $d$ band. The predictions of this model are consistent with the relatively small mass enhancement observed in Pd and suggest that a large paramagnon mass enhancement may be present in Sc.