Quasi-two-dimensional magnetic properties in atomic layer resolved La0.7Sr0.3MnO3/LaAlO3 superlattices br

Materials in low dimensions show interesting physics and excellent potential in practical applications.The atomic-level control of two-dimensional (2D) behavior in a traditional three-dimensional (3D) system isquite hard, and the (La0.7Sr0.3MnO3)n/(LaAlO3)n(LMSO/LAO) superlattice on a (001) SrTiO3substrate wasinvestigated to explore its quasi-2D behavior. The number of magnetic phase transitions has a close relationshipwith the number of unit cells (n): only one phase transition forn=2 and four phase transitions forn=8. Itwas found that the local structure of each La0.7Sr0.3MnO3atomic layer is responsible for the multiple phasetransitions: the gradual change of the tetragonal ratio and the in-plane tensile strain-induced 3delectronic orbitaloccupancy control the magnetic properties of 2D-LSMO atomic layers. For the outmost 2D-LSMO atomic layercontacting LaAlO3directly, interface-related factors reduce the intensity of magnetic interaction significantly.With the increase ofn, the properties around the LSMO/LAO interface changes, which demonstrates that thesuperlattice configuration and the lattice-mismatch strain could be employed to explore the quasi-2D behavior of a traditional 3D system