Symmetry Mismatched Heterostructures: New Routes to Bandwidth Control in Oxides
Technical Report,15 Apr 2012,14 Apr 2015
Drexel University Philadelphia
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This project aims to discover novel physical phenomena in correlated ABO3 oxide heterostructures by using interfacial coupling to controlthe behavior of BO6 octahedra, the connectivity of which are directly coupled to electronic bandwidth. Work on ultrathin La23Sr13MnO3films grown on LSAT and NdGaO3 substrates, which have the same lattice parameters but different crystal symmetry, has revealed asystematic divergence in properties as the film thickness is reduced. This study is a direct demonstration of how octahedral imprintingcontributes significantly to properties at oxide interfaces, and provides insight into the length scale associated with interfacial octahedralcoupling. A second goal of the project is to investigate structural coupling effects in isovalent complex oxide superlattices, allowing for theisolation of electronic effects driven by octahedral coupling. To this end, our work on La0.7Sr0.3MnO3Eu0.7Sr0.3MnO3 superlattices hasprovided the first direct experimental demonstration of how octahedral behavior in oxide heterostructures can be used to engineer spatiallyconfined or uniform macroscopic properties by varying the superlattice period with respect to the length scale of interfacial structuralcoupling. By varying the wavelength and amplitude of the octahedral modulations, a transition is induced from modulated magnetization inlarge-period superlattices to homogeneous magnetization in short-period superlattices.
- Inorganic Chemistry
- Nuclear Physics and Elementary Particle Physics