Unit-cell thick BaTiO{sub 3} blocks octahedral tilt propagation across oxide heterointerface

Journal Article · Wed May 14 04:00:00 UTC 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4875839· OSTI ID:22275567

Kan, Daisuke; Aso, Ryotaro ^[1]; Kurata, Hiroki; Shimakawa, Yuichi ^[1]

---

1. Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan)

We fabricated SrRuO{sub 3}/BaTiO{sub 3}/GdScO{sub 3} heterostructures in which the BaTiO{sub 3} layer is one unit cell thick by pulsed laser deposition and elucidated how the BaTiO{sub 3} layer influences structural and magneto-transport properties of the SrRuO{sub 3} layer through octahedral connections across the heterointerface. Our X-ray-diffraction-based structural characterizations show that while an epitaxial SrRuO{sub 3} layer grown directly on a GdScO{sub 3} substrate is in the monoclinic phase with RuO{sub 6} octahedral tilts, a one-unit-cell-thick BaTiO{sub 3} layer inserted between SrRuO{sub 3} and GdScO{sub 3} stabilizes the tetragonal SrRuO{sub 3} layer with largely reduced RuO{sub 6} tilts. Our high-angle annular dark-field and annular bright-field scanning transmission electron microscopy observations provide an atomic-level view of the octahedral connections across the heterostructure and reveal that the BaTiO{sub 3} layer only one unit cell thick is thick enough to stabilize the RuO{sub 6}-TiO{sub 6} octahedral connections with negligible in-plane oxygen atomic displacements. This results in no octahedral tilts propagating into the SrRuO{sub 3} layer and leads to the formation of a tetragonal SrRuO{sub 3} layer. The magneto-transport property characterizations also reveal a strong impact of the octahedral connections modified by the inserted BaTiO{sub 3} layer on the spin-orbit interaction of the SrRuO{sub 3} layer. The SrRuO{sub 3} layer on BaTiO{sub 3}/ GdScO{sub 3} has in-plane magnetic anisotropy. This is in contrast to the magnetic anisotropy of the monoclinic SrRuO{sub 3} films on the GdScO{sub 3} substrate, in which the easy axis is ∼45° to the film surface normal. Our results demonstrate that the one-unit-cell-thick layer of BaTiO{sub 3} can control and manipulate the interfacial octahedral connection closely linked to the structure-property relationship of heterostructures.

• OSTI ID: 22275567
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 18 Vol. 115; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANISOTROPY
ATOMIC DISPLACEMENTS
BARIUM COMPOUNDS
ENERGY BEAM DEPOSITION
EPITAXY
HETEROJUNCTIONS
L-S COUPLING
LASER RADIATION
LAYERS
MAGNETORESISTANCE
MONOCLINIC LATTICES
PULSED IRRADIATION
RUTHENIUM COMPOUNDS
SUBSTRATES
THIN FILMS
TITANATES
TITANIUM OXIDES
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION