Magnetic structures of highly frustrated pyrochlores
| Autor: | Mark Harris, D.F. McMorrow, P.J.C. King, Steven T. Bramwell, Th. Zeiske |
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| Rok vydání: | 1998 |
| Předmět: |
Physics
Spin glass Condensed matter physics Magnetic structure media_common.quotation_subject Geometrical frustration Pyrochlore Frustration engineering.material Condensed Matter Physics Condensed Matter::Disordered Systems and Neural Networks Electronic Optical and Magnetic Materials Ferromagnetism engineering Antiferromagnetism Condensed Matter::Strongly Correlated Electrons Ground state media_common |
| Zdroj: | Journal of Magnetism and Magnetic Materials. :757-762 |
| ISSN: | 0304-8853 |
| DOI: | 10.1016/s0304-8853(97)00796-8 |
| Popis: | In the pyrochlore lattice, the magnetic ions sit at the corners of a framework of corner-sharing tetrahedra. It is well known that this lattice results in a very high degree of geometrical frustration for antiferromagnetic interactions, but it will be shown that a similar degree of frustration occurs when the interactions are ferromagnetic, if there is also very strong axial single-ion anisotropy. The ground state is disordered down to 0 K, but with frozen dynamics, rather like a conventional spin glass. We show that the pyrochlore Ho2Ti2O7 corresponds to just such a frustrated ferromagnet, with a nearest-neighbour exchange energy of J = 1 K. Neutron scattering and mu SR data indicate that in zero field the magnetic ground state is disordered down to a temperature of at least 0.05 K. However, upon application of a magnetic field, the degeneracy is completely broken and a striking series of ordered phases is seen. We compare this behaviour with the related pyrochlore Er2Ti2O7. (C) 1998 Elsevier Science B.V. All rights reserved. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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