Charge ordered structure of magnetite Fe(3)O(4) below the Verwey transition
The crystal structure of highly stoichiometric magnetite (Fe3O4) below the Verwey transition has been refined from high-resolution neutron and synchrotron x-ray powder-diffraction data. The refined model has a monoclinic P2/c symmetry cell with orthorhombic Pmca pseudosymmetry constraints on the ato...
| Glavni autori: | , , |
|---|---|
| Format: | Journal article |
| Jezik: | English |
| Izdano: |
2002
|
| _version_ | 1826266337877426176 |
|---|---|
| author | Wright, J Attfield, J Radaelli, P |
| author_facet | Wright, J Attfield, J Radaelli, P |
| author_sort | Wright, J |
| collection | OXFORD |
| description | The crystal structure of highly stoichiometric magnetite (Fe3O4) below the Verwey transition has been refined from high-resolution neutron and synchrotron x-ray powder-diffraction data. The refined model has a monoclinic P2/c symmetry cell with orthorhombic Pmca pseudosymmetry constraints on the atomic positions, and contains four independent octahedral B site iron atoms. Charge ordering is evidenced by the presence of expanded and contracted BO6 octahedra, and by the distribution of B-B distances resulting from unequal Coulombic repulsions between the different B site charges. The B-B distances are inconsistent with dimer formation. Competition between the B-O and B-B interactions results in polar displacements of two of the B site cations. The charge ordering has a predominant [001] density modulation, which relieves a nesting instability in the electronic density of states, but a second [00 1/2] phase modulation also occurs. The monoclinic distortion at the Verwey transition is consistent with a macroscopic rhombohedral magnetostriction, driven by the localization of orbitally degenerate Fe2+, coincident with the microscopic charge ordering distortions that have an orthorhombic lattice symmetry. |
| first_indexed | 2024-03-06T20:37:23Z |
| format | Journal article |
| id | oxford-uuid:33140318-bf6a-42e5-a7b6-fc9a89ada446 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:37:23Z |
| publishDate | 2002 |
| record_format | dspace |
| spelling | oxford-uuid:33140318-bf6a-42e5-a7b6-fc9a89ada4462022-03-26T13:18:10ZCharge ordered structure of magnetite Fe(3)O(4) below the Verwey transitionJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:33140318-bf6a-42e5-a7b6-fc9a89ada446EnglishSymplectic Elements at Oxford2002Wright, JAttfield, JRadaelli, PThe crystal structure of highly stoichiometric magnetite (Fe3O4) below the Verwey transition has been refined from high-resolution neutron and synchrotron x-ray powder-diffraction data. The refined model has a monoclinic P2/c symmetry cell with orthorhombic Pmca pseudosymmetry constraints on the atomic positions, and contains four independent octahedral B site iron atoms. Charge ordering is evidenced by the presence of expanded and contracted BO6 octahedra, and by the distribution of B-B distances resulting from unequal Coulombic repulsions between the different B site charges. The B-B distances are inconsistent with dimer formation. Competition between the B-O and B-B interactions results in polar displacements of two of the B site cations. The charge ordering has a predominant [001] density modulation, which relieves a nesting instability in the electronic density of states, but a second [00 1/2] phase modulation also occurs. The monoclinic distortion at the Verwey transition is consistent with a macroscopic rhombohedral magnetostriction, driven by the localization of orbitally degenerate Fe2+, coincident with the microscopic charge ordering distortions that have an orthorhombic lattice symmetry. |
| spellingShingle | Wright, J Attfield, J Radaelli, P Charge ordered structure of magnetite Fe(3)O(4) below the Verwey transition |
| title | Charge ordered structure of magnetite Fe(3)O(4) below the Verwey transition |
| title_full | Charge ordered structure of magnetite Fe(3)O(4) below the Verwey transition |
| title_fullStr | Charge ordered structure of magnetite Fe(3)O(4) below the Verwey transition |
| title_full_unstemmed | Charge ordered structure of magnetite Fe(3)O(4) below the Verwey transition |
| title_short | Charge ordered structure of magnetite Fe(3)O(4) below the Verwey transition |
| title_sort | charge ordered structure of magnetite fe 3 o 4 below the verwey transition |
| work_keys_str_mv | AT wrightj chargeorderedstructureofmagnetitefe3o4belowtheverweytransition AT attfieldj chargeorderedstructureofmagnetitefe3o4belowtheverweytransition AT radaellip chargeorderedstructureofmagnetitefe3o4belowtheverweytransition |