  The emergence of the field of spintronics brought half-metallic ferromagnets
to the center of scientific research. A lot of interest was focused on newly
created transition-metal pnictides (such as CrAs) and chalcogenides (such as
CrTe) in the metastable zinc-blende lattice structure. These compounds were
found to present the advantage of high Curie temperature values in addition to
their structural similarity to semiconductors. Significant theoretical activity
has been devoted to the study of the electronic and magnetic properties of
these compounds in an effort to achieve a better control of their experimental
behaviour in realistic applications. This review is devoted to an overview of
the studies of these compounds, with emphasis on theoretical results, covering
their bulk properties (electronic structure, magnetism, stability of the
zinc-blende phase, stability of ferromagnetism) as well as low-dimensional
structures (surfaces, interfaces, nanodots and transition-metal delta-doped
semiconductors) and phenomena that can possibly destroy the half-metallic
property, like structural distortions or defects.
