Component-specific electromechanical response in a ferroelectric/dielectric superlattice.

Journal Article · Tue Nov 16 04:00:00 EST 2010 · Phys. Rev. B

DOI:https://doi.org/10.1103/PhysRevB.82.174116· OSTI ID:992836

Jo, J Y; Sichel, R J; Dufresne, E M; Lee, H N; Nakhmanson, S M; Evans, P G; ORNL,

The electronic and electromechanical properties of complex oxide superlattices are closely linked to the evolution of the structure and electrical polarization of the component layers in applied electric fields. Efforts to deduce the responses of the individual components of the superlattice to applied fields have focused on theoretical approaches because of the limitations of available experimental techniques. Time-resolved x-ray microdiffraction provides a precise crystallographic probe of each component using the shift in wave vector and change in intensity of superlattice satellite reflections. We report in detail the methods to measure and analyze the x-ray diffraction patterns in applied electric field and their application to a 2-unit-cell BaTiO{sub 3}/4-unit-cell CaTiO{sub 3} superlattice. We find that the overall piezoelectric distortion is shared between the two components. Theoretical predictions of the electromechanical properties of a superlattice with the same composition constrained to tetragonal symmetry are in excellent agreement with the experiments. Lattice instability analysis, however, suggests that the low-temperature ground state could exhibit antiferrodistortive rotations of TiO{sub 6} octahedra within and/or at the interfaces of the CaTiO{sub 3} component.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: SC; NSF
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 992836
• Report Number(s): ANL/MSD/JA-67439
• Journal Information: Phys. Rev. B, Journal Name: Phys. Rev. B Journal Issue: Nov. 16, 2010 Vol. 82; ISSN 1098-0121
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
CALCIUM OXIDES
ELECTRICAL PROPERTIES
ELECTROMECHANICS
GROUND STATES
SUPERLATTICES
SYMMETRY
TITANIUM OXIDES
X-RAY DIFFRACTION