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

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