Suppression of octahedral tilts and associated changes in electronic properties at epitaxial oxide heterostructure interfaces.

Epitaxial oxide interfaces with broken translational symmetry have emerged as a central paradigm behind the novel behaviors of oxide superlattices. Here, we use scanning transmission electron microscopy to demonstrate a direct, quantitative unit-cell-by-unit-cell mapping of lattice parameters and oxygen octahedral rotations across the BiFeO3-La0.7 Sr0.3 MnO3 interface to elucidate how the change of crystal symmetry is accommodated. Combined with low-loss electron energy loss spectroscopy imaging, we demonstrate a mesoscopic antiferrodistortive phase transition near the interface in BiFeO3 and elucidate associated changes in electronic properties in a thin layer directly adjacent to the interface.

[1]  A. Tagantsev,et al.  Ionic polarizability of conductive metal oxides and critical thickness for ferroelectricity in BaTiO3. , 2006, Physical review letters.

[2]  James F. Scott,et al.  Physics and Applications of Bismuth Ferrite , 2009 .

[3]  J. Junquera,et al.  Ferromagneticlike closure domains in ferroelectric ultrathin films: first-principles simulations. , 2008, Physical review letters.

[4]  R. Egerton.  Electron Energy-Loss Spectroscopy in the Electron Microscope , 1995, Springer US.

[5]  L. Reimer,et al.  Transmission electron microscopy , 2019, Bancroft's Theory and Practice of Histological Techniques.

[6]  D. Muller,et al.  Lattice-polarization effects on electron-gas charge densities in ionic superlattices , 2006, cond-mat/0602045.

[7]  V. Cros,et al.  Evidence for room-temperature multiferroicity in a compound with a giant axial ratio. , 2009, Physical review letters.

[8]  N. Reyren,et al.  Superconducting Interfaces Between Insulating Oxides , 2007, Science.

[9]  Volker Heine,et al.  Theory of Surface States , 1965 .

[10]  Akira Ohtomo,et al.  A high-mobility electron gas at the LaAlO3/SrTiO3 heterointerface , 2004, Nature.

[11]  Marin Alexe,et al.  Atomic-scale study of electric dipoles near charged and uncharged domain walls in ferroelectric films. , 2008, Nature materials.

[12]  Kresse,et al.  Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. , 1996, Physical review. B, Condensed matter.

[13]  A. Millis,et al.  Lattice relaxation in oxide heterostructures: LaTiO3/SrTiO3 superlattices. , 2006, Physical review letters.

[14]  Michael Faley,et al.  Oxygen octahedron reconstruction in the SrTiO 3 /LaAlO 3 heterointerfaces investigated using aberration-corrected ultrahigh-resolution transmission electron microscopy , 2009 .

[15]  I. Ponomareva,et al.  Nature of dynamical coupling between polarization and strain in nanoscale ferroelectrics from first principles. , 2008, Physical review letters.

[16]  M. J. Lee,et al.  Interface ferromagnetism and orbital reconstruction in BiFeO3-La(0.7)Sr(0.3)MnO3 heterostructures. , 2010, Physical review letters.

[17]  Rainer Waser,et al.  Unit-cell scale mapping of ferroelectricity and tetragonality in epitaxial ultrathin ferroelectric films. , 2007, Nature materials.

[18]  U Zeitler,et al.  Magnetic effects at the interface between non-magnetic oxides. , 2007, Nature materials.

[19]  L. Bellaiche,et al.  Electric-field-induced paths in multiferroic BiFeO3 from atomistic simulations. , 2009, Physical review letters.

[20]  L. Liz‐Marzán,et al.  Mapping surface plasmons on a single metallic nanoparticle , 2007 .

[21]  F. D. Abajo,et al.  Optical excitations in electron microscopy , 2009, 0903.1669.

[22]  U. V. Waghmare,et al.  First-principles study of spontaneous polarization in multiferroic BiFeO 3 , 2005 .

[23]  Philippe Ghosez,et al.  Improper ferroelectricity in perovskite oxide artificial superlattices , 2008, Nature.

[24]  R. Clarke,et al.  Structural basis for the conducting interface between LaAlO3 and SrTiO3. , 2007, Physical review letters.