Electron spin-flip relaxation by one magnon processes: Application to the gadolinium surface band

The "s-f model," also known as the ferromagnetic Kondo lattice, contains a description of band electrons coupled to localized spins that 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 1/tau approximate to0.1 eV agrees nicely with a measurement by Fedorov et al.