  The Hubbard model on fcc-type lattices is studied in the dynamical mean-field
theory of infinite spatial dimensions. At intermediate interaction strength
finite temperature Quantum Monte Carlo calculations yield a second order phase
transition to a highly polarized, metallic ferromagnetic state. The Curie
temperatures are calculated as a function of electronic density and interaction
strength. A necessary condition for ferromagnetism is a density of state with
large spectral weight near one of the band edges.
