Title Emergent long-range magnetic order in ultrathin (111)-oriented LaNiO3 films /
Authors Kane, Margaret M ; Vailionis, Arturas ; Riddiford, Lauren J ; Mehta, Apurva ; N’Diaye, Alpha T ; Klewe, Christoph ; Shafer, Padraic ; Arenholz, Elke ; Suzuki, Yuri
DOI 10.1038/s41535-021-00345-2
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Is Part of NPJ quantum materials.. Berlin : Nature research. 2021, vol. 6, iss. 1, art. no. 44, p. 1-6.. ISSN 2397-4648
Abstract [eng] The emergence of ferromagnetism in materials where the bulk phase does not show any magnetic order demonstrates that atomically precise films can stabilize distinct ground states and expands the phase space for the discovery of materials. Here, the emergence of long-range magnetic order is reported in ultrathin (111) LaNiO3 (LNO) films, where bulk LNO is paramagnetic, and the origins of this phase are explained. Transport and structural studies of LNO(111) films indicate that NiO6 octahedral distortions stabilize a magnetic insulating phase at the film/substrate interface and result in a thickness-dependent metal–insulator transition at t = 8 unit cells. Away from this interface, distortions relax and bulk-like conduction is regained. Synchrotron x-ray diffraction and dynamical x-ray diffraction simulations confirm a corresponding out-of-plane unit-cell expansion at the interface of all films. X-ray absorption spectroscopy reveals that distortion stabilizes an increased concentration of Ni2+ ions. Evidence of long-range magnetic order is found in anomalous Hall effect and magnetoresistance measurements, likely due to ferromagnetic superexchange interactions among Ni2+–Ni3+ ions. Together, these results indicate that long-range magnetic ordering and metallicity in LNO(111) films emerges from a balance among the spin, charge, lattice, and orbital degrees of freedom.
Published Berlin : Nature research
Type Journal article
Language English
Publication date 2021
CC license CC license description