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Emergent Ferromagnetism at the (111) LaNiO<sub>3</sub>/LaAlO<sub>3</sub> Interface

ORAL

Abstract

LaNiO3 (LNO) is unique among rare-earth nickelates because it is a paramagnetic metal at all temperatures, while others undergo magnetic and metal-insulator transitions. Recently, we have found that the unique strain state at the (111) LaNiO3/LaAlO3 interface stabilizes a ferromagnetic, insulating phase in LNO. The constraints on NiO6 octahedra at the (111)-oriented perovskite interface limit the tilts and rotations that usually relax strain in (001)-oriented films. X-ray diffraction and dynamical x-ray simulations show this results in an elongation of the out-of-plane lattice parameter in the first 5 unit cells of LNO(111) films. Transport measurements show the anomalous Hall effect and negative, hysteretic magnetoresistance in films up to 26 u.c.. This ferromagnetism can originate from Ni2+-Ni3+ superexchange interactions in the distorted, interfacial LNO(111). We also discuss the magnetic depth profile deduced from polarized neutron reflectometry. The emergence of ferromagnetism indicates a potential for increased functionality in other (111)-oriented perovskite films.

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Presenters

  • Margaret Kane

    Stanford Univ

Authors

  • Margaret Kane

    Stanford Univ

  • Arturas Vailionis

    Stanford Univ

  • Lauren Riddiford

    Stanford Univ, Applied Physics, Stanford University

  • Apurva Mehta

    Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford Synchrotron Radiation Lightsource, Stanford Synchrotron Radiation Lightsource, Menlo Park, CA, US, academic/physics, Stanford Synchrotron Radiation Lightsource

  • Alexander Grutter

    National Institute of Standards and Technology, Center for Neutron Research, National Institute of Standards and Technology, NIST Center for Neutron Research, NIST, NIST Gaithersburg

  • Purnima Parvathy Balakrishnan

    National Institute of Standards and Technology, NIST Center for Neutron Research, NIST

  • Alpha N'Diaye

    Advanced Light Source, Lawrence Berkeley National Laboratory, Advanced Light Source, Lawrence Berkeley National Laboratory, Lawrence Berkeley Laboratory, E O Lawrence Berkeley National Laboratory, Berkeley, CA, US, academic/govt, Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA

  • Yuri Suzuki

    Department of Applied Physics, Stanford University, Applied Physics, Stanford University, Stanford University, Stanford Univ