  The "s-f model", also known as the ferromagnetic Kondo lattice, contains a
description of band electrons coupled to localized spins which is an
appropriate description of the magnetic part of the low-energy physics of Gd
metal. Here the model is used to estimate the lifetime broadening of the
minority spin component of the surface electron band in ferromagnetic
gadolinium metal at temperatures below the Curie temperature. The low
temperature result 0.10 eV agrees nicely with a measurement by Fedorov et al.
