Tuning Magnetic Anisotropy by Interfacially Engineering the Oxygen Coordination Environment in a Transition-metal Oxide

Published in “”Nature Materials” (Online Publication, March 8, 2016).

Assoc Prof. Kan, D. Prof. Shimakawa, Y.(From Left)

Dr. Aso, R. Assit Prof. Haruta, M. Prof. Kurata, H.(From Left) 


Assoc Prof. Kan, D.; Ms. Sato, R.; Prof. Shimakawa, Y.
(Advanced Solid State Chemistry, International Research Center for Elements Science)


Dr. Aso, R.; Assist Prof. Haruta, M.; Prof. Kurata, H.
(Electron Microscopy and Crystal Chemistry, Advanced Research Center for Beam Science)


Controlling structural distortions that are closely related to functional properties in transition-metal oxides is a key not only to exploring novel phenomena but also to developing novel oxide-based electronic devices. Recent advances in atomic-level synthesis techniques have made it possible to fabricate artificial heterostructures with chemically abrupt interfaces consisting of dissimilar oxides. These heterostructures have provided a good platform for engineering novel bonding geometries that could lead to emergent phenomena not seen in bulk oxides. In this study, we show that the oxygen coordination environment of a perovskite, SrRuO3, can be controlled by heterostructuring SrRuO3 with a thin (0–4 monolayers thick) Ca0.5Sr0.5TiO3 layer grown on a GdScO3 substrate. A Ru-O-Ti bond angle characterizing the SrRuO3/Ca0.5Sr0.5TiO3 interface structure was found to be engineered by layer-by-layer control of the Ca0.5Sr0.5TiO3 layer thickness, and that the engineered Ru-O-Ti bond angle not only stabilizes a Ru-O-Ru bond angle never seen in bulk SrRuO3 but also tunes the magnetic anisotropy in the entire SrRuO3 layer. The results highlight the importance of the oxygen coordination environments as a key factor determining the structural and physical properties of the oxide heterostructures and show that the interface engineering of the oxygen atomic position is useful in controlling the oxygen environment.

Figure 1. (top) ABF-STEM images for the heterostructures with 1 – 4 monolayer thick Ca0.5Sr0.5TiO3 layer at the interface. The SRO/CSTO and CSTO/GSO interfaces are denoted by the blue and orange lines, respectively. (middle) M-O-M bond angle (M = Sc, Ti and Ru) as a function of the atomic position in the heterostructure. (bottom) Structure of the SrRuO3 layer in the heterostructure with the one- and four-monolayer-thick Ca0.5Sr0.5TiO3 layers.


Figure 2. Magnetic field dependence of the transverse Hall resistivity of the heterostructures with 0 – 4 monolayer thick Ca0.5Sr0.5TiO3 layer at the interface.


This work was partially supported by the Core Research for Evolutional Science and Technology (CREST) program of the Japan Science and Technology Agency. The work was also supported by a grant for the Joint Project of Chemical Synthesis Core Research Institutions from the Ministry of Education, Culture, Sports, Science and Technology of Japan.

Kan, D.; Aso, R.; Sato, R.; Haruta, M.; Kurata, H.; Shimakawa, Y., Tuning Magnetic Anisotropy by Interfacially Engineering the Oxygen Coordination Environment in a Transition-metal Oxide, Nature Materials, DOI: 10.1038/NMAT4580 (2016).