Martensitic transition and magnetoresistance in Cu-Al-Mn shape-memory alloy: Influence of ageing
We have studied the effect of ageing within the miscibility gap on the electric, magnetic, and thermodynamic properties of a nonstoichiometric Heusler Cu-Al-Mn shape-memory alloy, which undergoes a martensitic transition from a bcc-based structure (b phase! towards a close-packed structure (M phase!...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2002 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/10522 |
| Acceso en línea: | https://hdl.handle.net/2445/10522 |
| Access Level: | acceso abierto |
| Palabra clave: | Transformacions martensítiques Magnetoresistència Aliatges Martensitic transformations Magnetoresistance Alloys |
| Sumario: | We have studied the effect of ageing within the miscibility gap on the electric, magnetic, and thermodynamic properties of a nonstoichiometric Heusler Cu-Al-Mn shape-memory alloy, which undergoes a martensitic transition from a bcc-based structure (b phase! towards a close-packed structure (M phase!. Negative magnetoresistance that shows an almost linear dependence on the square of magnetization with different slopes in the M and b phases was observed. This magnetoresistive effect has been associated with the existence of Mn-rich clusters with the Cu2AlMn structure. The effect of an applied magnetic field on the martensitic transition has also been studied. The entropy change between the b and M phases shows negligible dependence on the magnetic field, but it decreases significantly with annealing time within the miscibility gap. Such a decrease is due to the increasing amount of Cu2MnAl-rich domains that do not transform martensitically. |
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