The domain walls of antiferromagnetic TbMnO$_{3}$ thin films
ORAL
Abstract
In bulk TbMnO$_{3}$ below 28K, the Mn sublattice orders as an antiferromagnetic cycloidal spin structure. This breaks inversion symmetry and induces a macroscopic electrical polarization: TbMnO$_{3}$ is a multiferroic material with a strong magnetoelectric coupling. Contrary to the bulk, TbMnO$_{3}$ thin films grown on (001)-SrTiO$_{3}$ substrates show ferromagnetic-like behavior with a magnetic moment of 1.5$\mu_{\mathrm{B}}$/f.u. at 15K. However, the thickness dependence of the magnetic moments is not consistent with magnetism homogeneously distributed through the film. Additionally, epitaxial strain enables the stabilization of different symmetries and particular domain configurations at nanometric scales. Large strain gradients and/or lowering of symmetry at the boundaries of these domains allow the appearance of physical responses distinct from those of the domains. In this work we investigate the contribution of the domain walls to the magnetic moment.
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