Effect of the substrate ferroelastic transition on epitaxial La<Subscript>0.7</Subscript>Sr<Subscript>0.3</Subscript>MnO<Subscript>3</Subscript> films grown on LaAlO<Subscript>3</Subscript>

Thin films of La<Subscript>0.7</Subscript>Sr<Subscript>0.3</Subscript>MnO<Subscript>3</S ubscript> were grown by molecular beam epitaxy on (001)LaAlO<Subscript>3</Subscript> crystals. High resolution X-ray diffraction analysis proves the presence of twins in the films at room temperature, showing that the twin structure of the substrate which forms at the <InlineEquation ID="Equ1"> <EquationSource Format="TEX">$Pm\bar {3}m\to R\bar {3}c$</EquationSource> </InlineEquation> ferroelastic transition at T<Subscript>F</Subscript>=813 K served as a template for the film microstructure. Magnetic measurements indicate a thermomagnetic irreversibility which is ascribed to the quenched disorder related to twinning and discussed in terms of coexisting ferromagnetic and spin disordered regions connected with the undeformed domain cores and strained domain walls respectively. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2007