Anomalies related to the TA2 phonon mode condensation in the Heusler Ni2MnGa alloy
We present specific-heat, elastic constants, and magnetic susceptibility measurements in a ferromagnetic Ni 2 MnGa Heusler alloy, in a temperature range where partial condensation of the [110] TA 2 phonon at q=0.33, accompanied by the development of a micromodulated structure has been reported to oc...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 1997 |
| País: | España |
| Institución: | Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya) |
| Repositorio: | Recercat. Dipósit de la Recerca de Catalunya |
| OAI Identifier: | oai:recercat.cat:2445/10467 |
| Acceso en línea: | https://hdl.handle.net/2445/10467 |
| Access Level: | acceso abierto |
| Palabra clave: | Materials magnètics Propietats magnètiques Transformacions martensítiques Magnetic materials Magnetic properties Martensitic transformations |
| Sumario: | We present specific-heat, elastic constants, and magnetic susceptibility measurements in a ferromagnetic Ni 2 MnGa Heusler alloy, in a temperature range where partial condensation of the [110] TA 2 phonon at q=0.33, accompanied by the development of a micromodulated structure has been reported to occur. All these quantities have been found to exhibit anomalous behavior at the temperature of condensation. From the results presented, it can be concluded that the appearance of the micromodulated structure takes place via a phase transition which is very weakly first order. It is found that at the transition point there is a significant reduction of the dynamical stability of the lattice not just for the transverse phonon at q=0.33, but also for any shear long wavelength distortion. It is particularly remarkable the large softening of C′ (around 60%) at the transition point. Finally, it is also shown that the intermediate transition is related to a magnetoelastic interaction. |
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