  Novel or unusual magnetism is a subject of considerable interest,
particularly in metals and degenerate semiconductors. In such materials the
interplay of magnetism, transport and other Fermi liquid properties can lead to
fascinating physical behavior. One example is in magnetic semiconductors, where
spin polarized currents may be controlled and used. We report density
functional calculations predicting magnetism in doped semiconducting beta-FeSi2
and CrSi2 at relatively low doping levels particularly for n-type. In this
case, there is a rapid cross-over to a half-metallic state as a function of
doping level. The results are discussed in relation to the electronic structure
and other properties of these compounds.
