Emergent long-range magnetic order in ultrathin (111)-oriented LaNiO3 films
| Autor: | Alpha T. N'Diaye, Elke Arenholz, Lauren Riddiford, Apurva Mehta, Padraic Shafer, Yuri Suzuki, Arturas Vailionis, Margaret Kane, Christoph Klewe |
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| Přispěvatelé: | Nanjing University, „Springer Nature' grupė |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Absorption spectroscopy Condensed matter physics Magnetoresistance 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Electronic Optical and Magnetic Materials Paramagnetism Condensed Matter::Materials Science Ferromagnetism Superexchange Hall effect Phase (matter) 0103 physical sciences TA401-492 Atomic physics. Constitution and properties of matter 010306 general physics 0210 nano-technology Spin (physics) Materials of engineering and construction. Mechanics of materials QC170-197 |
| Zdroj: | npj Quantum Materials, Vol 6, Iss 1, Pp 1-6 (2021) |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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