Coupling between lattice distortions and magnetism in La0.9Sr0.1MnO3 thin films

X-ray scattering experiments have demonstrated that for thin lms (100 Angst rom to 500 Angstrom) of La0.9Sr0.1MnO3 epitaxially grown on SrTiO3 (100) su bstrates, the accommodation of the lattice mismatch between lm and substrat e gives rise to a modulated structure. The non-bulk like structural propert ies of these thin lms are the origin of anomalies in the electronic and mag netic behavior. Studies of the lattice as a function of temperature clearly reveal a magnetostrictive effect close to the Curie temperature. For thick er lms the strain relief mechanism is replaced by formation of coherent mic rotwins and some of the bulk properties are recovered, but some differences are still observed.