Orbital degeneracy removed by charge order in triangular antiferromagnet AgNiO2.
We report a high-resolution neutron diffraction study on the orbitally degenerate spin-1/2 hexagonal metallic antiferromagnet AgNiO2. A structural transition to a tripled unit cell with expanded and contracted NiO6 octahedra indicates sqrt[3]xsqrt[3] charge order on the Ni triangular lattice. This s...
| Үндсэн зохиолчид: | , , , , , , , , |
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| Формат: | Journal article |
| Хэл сонгох: | English |
| Хэвлэсэн: |
2007
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| _version_ | 1826305829643485184 |
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| author | Wawrzyńska, E Coldea, R Wheeler, E Mazin, I Johannes, MD Sörgel, T Jansen, M Ibberson, R Radaelli, P |
| author_facet | Wawrzyńska, E Coldea, R Wheeler, E Mazin, I Johannes, MD Sörgel, T Jansen, M Ibberson, R Radaelli, P |
| author_sort | Wawrzyńska, E |
| collection | OXFORD |
| description | We report a high-resolution neutron diffraction study on the orbitally degenerate spin-1/2 hexagonal metallic antiferromagnet AgNiO2. A structural transition to a tripled unit cell with expanded and contracted NiO6 octahedra indicates sqrt[3]xsqrt[3] charge order on the Ni triangular lattice. This suggests charge order as a possible mechanism of lifting the orbital degeneracy in the presence of charge fluctuations, as an alternative to the more usual Jahn-Teller distortions. A novel magnetic ground state is observed at low temperatures with the electron-rich S=1 Ni sites arranged in alternating ferromagnetic rows on a triangular lattice, surrounded by a honeycomb network of nonmagnetic and metallic Ni ions. We also report first-principles band-structure calculations that explain microscopically the origin of these phenomena. |
| first_indexed | 2024-03-07T06:38:48Z |
| format | Journal article |
| id | oxford-uuid:f891b25d-649a-41fb-904d-a8c3775a6859 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T06:38:48Z |
| publishDate | 2007 |
| record_format | dspace |
| spelling | oxford-uuid:f891b25d-649a-41fb-904d-a8c3775a68592022-03-27T12:51:14ZOrbital degeneracy removed by charge order in triangular antiferromagnet AgNiO2.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:f891b25d-649a-41fb-904d-a8c3775a6859EnglishSymplectic Elements at Oxford2007Wawrzyńska, EColdea, RWheeler, EMazin, IJohannes, MDSörgel, TJansen, MIbberson, RRadaelli, PWe report a high-resolution neutron diffraction study on the orbitally degenerate spin-1/2 hexagonal metallic antiferromagnet AgNiO2. A structural transition to a tripled unit cell with expanded and contracted NiO6 octahedra indicates sqrt[3]xsqrt[3] charge order on the Ni triangular lattice. This suggests charge order as a possible mechanism of lifting the orbital degeneracy in the presence of charge fluctuations, as an alternative to the more usual Jahn-Teller distortions. A novel magnetic ground state is observed at low temperatures with the electron-rich S=1 Ni sites arranged in alternating ferromagnetic rows on a triangular lattice, surrounded by a honeycomb network of nonmagnetic and metallic Ni ions. We also report first-principles band-structure calculations that explain microscopically the origin of these phenomena. |
| spellingShingle | Wawrzyńska, E Coldea, R Wheeler, E Mazin, I Johannes, MD Sörgel, T Jansen, M Ibberson, R Radaelli, P Orbital degeneracy removed by charge order in triangular antiferromagnet AgNiO2. |
| title | Orbital degeneracy removed by charge order in triangular antiferromagnet AgNiO2. |
| title_full | Orbital degeneracy removed by charge order in triangular antiferromagnet AgNiO2. |
| title_fullStr | Orbital degeneracy removed by charge order in triangular antiferromagnet AgNiO2. |
| title_full_unstemmed | Orbital degeneracy removed by charge order in triangular antiferromagnet AgNiO2. |
| title_short | Orbital degeneracy removed by charge order in triangular antiferromagnet AgNiO2. |
| title_sort | orbital degeneracy removed by charge order in triangular antiferromagnet agnio2 |
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