| AVS 63rd International Symposium & Exhibition | |
| Thin Film | Tuesday Sessions |
| Session TF+SA+MI-TuM |
| Session: | Thin Films for Synchrotron and Magnetism Applications |
| Presenter: | Ryan Comes, Auburn University |
| Authors: | R. Comes, Auburn University S.C. Lin, University of California, Davis C.T. Kuo, Lawrence Berkeley National Laboratory (LBNL) L. Plucinski, FZ Juelich S. Spurgeon, Pacific Northwest National Laboratory D. Kepaptsoglou, SuperSTEM Q. Ramasse, SuperSTEM J.E. Rault, Synchrotron SOLEIL S. Nemsak, Forschungszentrum Juelich GmbH, Germany C. Fadley, Lawrence Berkeley National Laboratory (LBNL) P.V. Sushko, Pacific Northwest National Laboratory S.A. Chambers, Pacific Northwest National Laboratory |
| Correspondent: | Click to Email |
The polar discontinuity at the interface between SrTiO3 (STO) and LaCrO3 (LCO) has been shown to produce a varying band alignment between the two materials with a built-in potential gradient.1 We have recently shown that this built-in potential gradient can be harnessed to induce a polarization in STO-LCO superlattices through interface engineering.2 This work demonstrated that by controlling interfacial termination between layers we can induce a built-in polarization in STO, with Ti cations displaced off-center in surrounding oxygen octahedra. To further study this system, we have synthesized a series of STO-LCO superlattices with varying interfacial and surface terminations for synchrotron standing-wave x-ray photoemission measurements.3 These measurements make use of Bragg diffraction from the superlattice to induce an x-ray standing wave that can be scanned across a single period of the superlattice. Through careful material design, we have achieved the strongest standing-wave effects to date, enabling angle-resolved photoemission measurements of electronic dispersion in both the STO and LCO layers of the material. Density functional theory models of the electronic structure of the superlattices are used to corroborate our experimental results with the expected behavior. Monochromated, aberration-corrected scanning transmission electron microscopy electron energy-loss spectroscopy (STEM-EELS) measurements also enable further studies into changes in electronic behavior at interfaces.
1 S.A. Chambers, L. Qiao, T.C. Droubay, T.C. Kaspar, B.W. Arey, and P.V. Sushko, Phys. Rev. Lett. 107, 206802 (2011).
2 R.B. Comes, S.R. Spurgeon, S.M. Heald, D.M. Kepaptsoglou, L. Jones, P.V. Ong, M.E. Bowden, Q.M. Ramasse, P.V. Sushko, and S.A. Chambers, Adv. Mater. Interfaces, (2016). DOI: 10.1002/admi.201500779
3 A.X. Gray, C. Papp, B. Balke, S.-H. Yang, M. Huijben, E. Rotenberg, A. Bostwick, S. Ueda, Y. Yamashita, K. Kobayashi, E.M. Gullikson, J.B. Kortright, F.M.F. de Groot, G. Rijnders, D.H.A. Blank, R. Ramesh, and C.S. Fadley, Phys. Rev. B 82, 205116 (2010).