  We investigate the structure of magnetic domain walls in a classical double
exchange ferromagnet, evaluating domain wall energies and charges. Three
different cases are studied: (i) a conventional smooth Bloch wall, (ii) an
abrupt Ising-type wall, which is shown to have lower energy at small values of
carrier concentration, and (iii) stripe wall, corresponding to the two
ferromagnetic domains being separated by a stripe of another,
antiferromagnetic, phase. General aspects of energy balance and geometry of
phase-separated states are discussed in this context. It is speculated that
domain walls of the latter type may be responsible for the unusual transport
properties of certain manganate films.
