| Affiliation: | 1. Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou, 313001 P. R. China School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054 China;2. Beijing Computational Science Research Center, Beijing, 100193 China;3. School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054 China;4. Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 USA;5. Materials Genome Institute and Department of Physics, Shanghai University, Shanghai, 200444 China;6. School of Materials, University of New South Wales, Sydney, NSW, 2052 Australia;7. Department of Mechanical Engineering & Materials Science, and Institute of Materials Science & Engineering, Washington University in St. Louis, St. Louis, MO, 63130 USA;8. Global Innovative Centre for Advanced Nanomaterials, School of Engineering, The University of Newcastle, Callaghan, NSW, 2308 Australia;9. School of Chemistry and Physics, Queensland University of Technology, Brisbane, QLD, 4001 Australia;10. Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou, 313001 P. R. China |
| Abstract: | Interface plays a critical role in determining the physical properties and device performance of heterostructures. Traditionally, lattice mismatch, resulting from the different lattice constants of the heterostructure, can induce epitaxial strain. Over past decades, strain engineering has been demonstrated as a useful strategy to manipulate the functionalities of the interface. However, mismatch of crystal symmetry at the interface is relatively less studied due to the difficulty of atomically structural characterization, particularly for the epitaxy of low symmetry correlated materials on the high symmetry substrates. Overlooking those phenomena restrict the understanding of the intrinsic properties of the as- determined heterostructure, resulting in some long-standing debates including the origin of magnetic and ferroelectric dead layers. Here, perovskite LaCoO3-SrTiO3 superlattice (SL) is used as a model system to show that the crystal symmetry effect can be isolated by the existing interface strain. Combining the state-of-art diffraction and electron microscopy, it is found that the symmetry mismatch of LaCoO3-SrTiO3 SL can be tuned by manipulating the SrTiO3 layer thickness to artificially control the magnetic properties. The work suggests that crystal symmetry mismatch can also be designed and engineered to act as an effective strategy to generate functional properties of perovskite oxides. |
