Research Update: Interface-engineered oxygen octahedral tilts in perovskite oxide heterostructures

Abstract

Interface engineering of structural distortions is a key for exploring the functional properties of oxide heterostructures and superlattices. In this paper, we report on our comprehensive investigations of oxygen octahedral distortions at the heterointerface between perovskite oxides SrRuO3 and BaTiO3 on GdScO3 substrates and of the influences of the interfacially engineered distortions on the magneto-transport properties of the SrRuO3 layer. Our state-of-the-art annular bright-field imaging in aberration-corrected scanning transmission electron microscopy revealed that the RuO6 octahedral distortions in the SrRuO3 layer have strong dependence on the stacking order of the SrRuO3 and BaTiO3 layers on the substrate. This can be attributed to the difference in the interfacial octahedral connections. We also found that the stacking order of the oxide layers has a strong impact on the magneto-transport properties, allowing for control of the magnetic anisotropy of the SrRuO3 layer through interface engineering. Our results demonstrate the significance of the interface engineering of the octahedral distortions on the structural and physical properties of perovskite oxides.

Chemical-bond effect on epitaxial strain in perovskite sodium niobate

“…Because the lattices of the NNO films are clamped by the cubic substrates, the relaxation of the total strain by tilting is suppressed at the interfaces. 42 Consequently, the perovskite cell elongates in the out-of-plane direction. As revealed by XRD, the elongation is somewhat larger in the 10 nm-thick NNO/STO film than in the 10 nm-thick NNO/LSAT film, which is consistent with the larger total strain in the film on STO.…”

Defect‐Induced Anomalous Transverse Resistivity in an Itinerant Ferromagnetic Oxide

“…In this study, we focus on the perovskite‐structured itinerant ferromagnet SrRuO 3 (SRO) with a strong spin‐orbit interaction. Previously, it was shown that when SRO films are epitaxially grown on orthorhombic perovskite substrates such as (110) GdScO 3 (GSO), with oxygen octahedral rotations, the RuORu bond angle in the film/substrate interface region (2–3 nm‐thick) undergoes gradual changes as a result of accommodation of the structural mismatch between the films and the substrates (Figure S1 in the supplementary information) . Such gradual changes in the bond angle can break the spatial inversion symmetry and induce additional magnetic interactions such as the DM interaction.…”

“…Previously, it was shown that when SRO films are epitaxially grown on orthorhombic perovskite substrates such as (110) GdScO 3 (GSO), with oxygen octahedral rotations, the Ru─O─Ru bond angle in the film/substrate interface region (2-3 nm-thick) undergoes gradual changes as a result of accommodation of the structural mismatch between the films and the substrates ( Figure S1 in the supplementary information). [23][24][25] Such gradual changes in the bond angle can break the spatial inversion symmetry and induce additional magnetic interactions such as the DM interaction. This implies that when the film is thin enough, a magnetic structure in SRO would be somehow modulated, thereby influencing the magneto-transport properties.…”

Enhanced metallic properties of SrRuO3 thin films via kinetically controlled pulsed laser epitaxy

“…The XRD θ-2θ scan of the test-grown SRO thin film shows a slight increase in the out-of-plane lattice parameter (decrease in 2θ values) compared to an optimal 16 nm-thick SRO thin film, as shown in Fig. 4 (b [31][32][33] . However, in our SRO thin films grown on GSO substrates, the laser beam spot size and, hence, the film deposition rate are shown to have a more significant role in their transport properties than the interfacial contributions (see Fig.…”