Strain and magnetism in (La0.7Sr0.3)MnO3 very thin films epitaxially grown on SrTiO3

We study the epitaxial growth of (La0.7Sr0.3)MnO3 on SrTiO3 by pulsed laser deposition. This paper presents some magnetic and structural properties of these films, with the stress on very thin films (5 and 23 nm). We show that such films, although strained, still have a Curie temperature well above 300 K. These very thin films keep their properties over measurement periods of several months. A key feature of their microstructure is that it includes rhombohedral distortions of the tetragonal geometry imposed by the epitaxial strain. However, this microstructure appears sensitive to the electron beam of a transmission electron microscope.