Spin-resolved photoemission study of photohole lifetimes in ferromagnetic gadolinium

High-resolution spin-resolved photoemission is used to probe the decay channels available to a photohole created in a Gd(0001) surface state. The photoemission linewidths show that at low temperatures, the lifetime of a majority-spin hole is predominantly limited by electron-phonon scattering and that of a minority-spin hole by electron-magnon scattering. With increasing temperature this state shows both spin-mixing behavior reflecting the exchange of magnons and a reduced exchange splitting.