The role of strain in magnetic anisotropy of manganite thin films

Abstract
We show the importance of the role of strain in La 0.7 Sr 0.3 MnO 3 films by revealing the dominance of stress anisotropy effects over magnetocrystalline anisotropy effects in the magnetic anisotropy of these films. Magnetic anisotropy measurements of (001) and (110) La 0.7 Sr 0.3 MnO 3 thin films on SrTiO 3 and LaGaO 3 substrates, with excellent structural quality, reveal twofold symmetry on (110) La 0.7 Sr 0.3 MnO 3 films and fourfold symmetry on (001) films. Such symmetries can only be explained by stress anisotropy contributions in the plane of the film. In conjunction with the thickness dependence of the magnetic properties, the results indicate the dominant role of strain in the magnetic properties of these doped manganites.