Octahedral continuity and emergent magnetism in confined SrRuO<sub>3</sub>

ORAL

Abstract

We report experimental and theoretical investigations of emergent properties of heterostructures with one- or two-unit cells of SrRuO3 (SRO) between two materials, SrTiO3 (STO, insulating, diamagnetic) or CaRuO3 (CRO, metallic, paramagnetic). In STO5/SRO1/STO5, where the RuO6 octahedra network is not continuous across the interface, SRO is cubic and the film is nonmagnetic and insulating, but in CRO5/SRO1/CRO5, the RuO6 octahedra network is continuous, the structure is orthorhombic and the film is ferromagnetic (FM) and metallic. Transmission electron microscopy/spectroscopy show no octahedral tilts in STO5/SRO1/STO5 while in the CRO5/SRO1/CRO5 the tilt angle is larger than in bulk SRO. STO5/SRO2/STO5 is strongly FM [TC~120K] replicating a Curie-Weiss behavior. CRO5/SRO2/CRO5 is FM with slightly larger , exhibiting magnetism similar to a Griffiths phase. Density-functional-theory (DFT) calculations reproduce and provide insights into the structural, electronic and magnetic properties of the heterostructures. The highly localized Ru 4d orbitals are responsible for both the insulating and nonmagnetic behavior in STO5/SRO1/STO5. Our study shows that in the ultrathin limit, a continuous RuO6 octahedra network is key to the magnetic behavior of ruthenates.

*Supported by DoE.

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Presenters

  • Zeeshan Ali

    • Department of Physics and Astronomy, Louisiana State University

Authors

  • Zeeshan Ali

    • Department of Physics and Astronomy, Louisiana State University

  • Mohammad Saghayezhian

    • Department of Physics and Astronomy, Louisiana State University
    • Louisiana State University

  • Donghan Shin

    • Department of Physics and Astronomy, Vanderbilt Univ
    • Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235, USA
    • Department of Physics and Astronomy, Vanderbilt University

  • Zhen Wang

    • Department of Physics and Astronomy, Louisiana State University
    • Condensed Matter Physics & Materials Science Department, Brookhaven National Lab

  • Andrew O'Hara

    • Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235, USA
    • Department of Physics and Astronomy, Vanderbilt University
    • Department of Physics and Astronomy, Vanderbilt University, Nashville, TN
    • Vanderbilt University

  • Prahald Siwakoti

    • Department of Physics and Astronomy, Louisiana State University
    • Louisiana State University

  • David Howe

    • Department of Physics and Astronomy, Louisiana State University

  • Yimei Zhu

    • Brookhaven National Laboratory
    • Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory
    • Condensed Matter Physics & Materials Science Department, Brookhaven National Lab
    • Condensed Matter Physics & Materials Science Department, Brookhaven National Laboratory
    • Condensed Matter Physics, Brookhaven National Laboratory

  • Sokrates T Pantelides

    • Department of Physics and Engineering, Vanderbilt University
    • Department of Physics and Astronomy, Vanderbilt Univ
    • Department of Physics and Astronomy, Vanderbilt University
    • Vanderbilt Univ
    • Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235, USA
    • Institute of Physics, Chinese Academy of Sciences
    • Department of Physics and Astronomy & Department of Electrical Engineering and Computer Science, Vanderbilt University
    • Department of Physics and Astronomy and Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN
    • Department of Electrical Engineering and Computer Science, Vanderbilt University
    • Department of Physics and Astronomy and Department of Electrical Engineering and Computer Science, Vanderbilt University
    • Vanderbilt University

  • Jiandi Zhang

    • Department of Physics and Astronomy, Louisiana State University
    • Louisiana State University