  We study the effect of the shape anisotropy on the magnetic domain
configurations of a ferromagnetic semiconductor (Ga,Mn)As/GaAs(001) epitaxial
wire as a function of temperature. Using magnetoresistance measurements, we
deduce the magnetic configurations and estimate the relative strength of the
shape anisotropy compared with the intrinsic anisotropies. Since the intrinsic
anisotropy is found to show a stronger temperature dependence than the shape
anisotropy, the effect of the shape anisotropy on the magnetic domain
configuration is relatively enhanced with increasing temperature. This
information about the shape anisotropy provides a practical means of designing
nanostructured spin electronic devices using (Ga,Mn)As.
