Structural phase transitions in geometrically frustrated antiferromagnets
We study geometrically frustrated antiferromagnets with magnetoelastic coupling. Frustration in these systems may be relieved by a structural transition to a low temperature phase with reduced lattice symmetry. We examine the statistical mechanics of this transition and the effects on it of quenched...
| Main Authors: | , |
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| Format: | Journal article |
| Language: | English |
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2008
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| _version_ | 1797073786112049152 |
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| author | Saunders, T Chalker, J |
| author_facet | Saunders, T Chalker, J |
| author_sort | Saunders, T |
| collection | OXFORD |
| description | We study geometrically frustrated antiferromagnets with magnetoelastic coupling. Frustration in these systems may be relieved by a structural transition to a low temperature phase with reduced lattice symmetry. We examine the statistical mechanics of this transition and the effects on it of quenched disorder, using Monte Carlo simulations of the classical Heisenberg model on the pyrochlore lattice with coupling to uniform lattice distortions. The model has a transition between a cubic, paramagnetic high-temperature phase and a tetragonal, Neel ordered low-temperature phase. It does not support the spin-Peierls phase, which is predicted as an additional possibility within Landau theory, and the transition is first-order for reasons unconnected with the symmetry analysis of Landau theory. Quenched disorder stabilises the cubic phase, and we find a phase diagram as a function of temperature and disorder strength similar to that observed in ZnCdCrO. |
| first_indexed | 2024-03-06T23:27:02Z |
| format | Journal article |
| id | oxford-uuid:6ab6d741-98bd-4692-959e-a6460c5bb8d6 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T23:27:02Z |
| publishDate | 2008 |
| record_format | dspace |
| spelling | oxford-uuid:6ab6d741-98bd-4692-959e-a6460c5bb8d62022-03-26T18:59:16ZStructural phase transitions in geometrically frustrated antiferromagnetsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:6ab6d741-98bd-4692-959e-a6460c5bb8d6EnglishSymplectic Elements at Oxford2008Saunders, TChalker, JWe study geometrically frustrated antiferromagnets with magnetoelastic coupling. Frustration in these systems may be relieved by a structural transition to a low temperature phase with reduced lattice symmetry. We examine the statistical mechanics of this transition and the effects on it of quenched disorder, using Monte Carlo simulations of the classical Heisenberg model on the pyrochlore lattice with coupling to uniform lattice distortions. The model has a transition between a cubic, paramagnetic high-temperature phase and a tetragonal, Neel ordered low-temperature phase. It does not support the spin-Peierls phase, which is predicted as an additional possibility within Landau theory, and the transition is first-order for reasons unconnected with the symmetry analysis of Landau theory. Quenched disorder stabilises the cubic phase, and we find a phase diagram as a function of temperature and disorder strength similar to that observed in ZnCdCrO. |
| spellingShingle | Saunders, T Chalker, J Structural phase transitions in geometrically frustrated antiferromagnets |
| title | Structural phase transitions in geometrically frustrated
antiferromagnets |
| title_full | Structural phase transitions in geometrically frustrated
antiferromagnets |
| title_fullStr | Structural phase transitions in geometrically frustrated
antiferromagnets |
| title_full_unstemmed | Structural phase transitions in geometrically frustrated
antiferromagnets |
| title_short | Structural phase transitions in geometrically frustrated
antiferromagnets |
| title_sort | structural phase transitions in geometrically frustrated antiferromagnets |
| work_keys_str_mv | AT saunderst structuralphasetransitionsingeometricallyfrustratedantiferromagnets AT chalkerj structuralphasetransitionsingeometricallyfrustratedantiferromagnets |