  The domain configuration of 50 nm thick La0.7SrMnO3 films has been directly
investigated using scanning electron microscopy with polarization analysis
(SEMPA), with magnetic contrast obtained without the requirement for prior
surface preparation. The large scale domain structure reflects a primarily
four-fold anisotropy, with a small uniaxial component, consistent with
magneto-optic Kerr effect measurements. We also determine the domain transition
profile and find it to be in agreement with previous estimates of the domain
wall width in this material. The temperature dependence of the image contrast
is investigated and compared to superconducting-quantum interference device
magnetometry data. A faster decrease in the SEMPA contrast is revealed, which
can be explained by the technique's extreme surface sensitivity, allowing us to
selectively probe the surface spin polarization which due to the double
exchange mechanism exhibits a distinctly different temperature dependence than
the bulk magnetization.
