Magnetic domain structure and lattice distortions in manganite films under tensile strain.

We performed detailed studies of the magnetic domain structure and strain effects in epitaxial La[SUB1-x]Sr[SUBx]MnO[SUB3](001) films grown on SrTiO[SUB3](001) bicrystal substrates by combining magnetic force microscopy, x-ray diffraction, and classical magnetometry. We show that, in addition to magnetic domain walls which nucleate at grain boundaries, 180° magnetic domain walls not associated with structural defects form along the 〈100〉 direction. The size of the magnetic domains are of the order of tens of microns with the magnetic easy axes along the 〈100〉 direction in the plane of the film. Spin reorientation occurs at the grain boundaries, which we attribute to the different strain state compared to the grain interior. [ABSTRACT FROM AUTHOR]