| Titre : | Entropy change and kinetic effects at the magnetostructural phase transition of MnBi (2014) |
| Titre original : | Changement d'entropie et effets cinétiques à la transition de phase magnétostructurelle de MnBi |
| Auteurs : | Vittorio Basso, Auteur ; Elena Sonia Olivetti, Auteur ; Luca Martino, Auteur |
| Type de document : | Article : texte imprimé |
| Dans : | International journal of refrigeration (Vol. 37 N° 1, Janvier 2014) |
| Article en page(s) : | pp. 266–272 |
| Note générale : | Refrigeration |
| Langues : | Anglais |
| Tags : | Magnetocaloric effect ; MnBi ; kinetic effects ; first order phase transition |
| Résumé : | In this paper we investigate the entropy change and the kinetics at the magneto-structural transition (at 628 K) of polycrystalline MnBi. Samples were prepared by rapid quenching and annealing and exhibit 86 wt% of the hexagonal MnBi phase. The entropy change at the transition is found to be Δs = 17.6 J kg−1 K−1 and the magnetic field shifts the transition temperature at a rate of 2.6 K T−1. The temperature hysteresis, of 19 K, is quite large for magneto-thermal application. The transition shows kinetics effects upon cooling in which the transition temperature is found to depend approximately to the logarithm of the temperature rate with coefficient −3.8 K. |
| En ligne : | http://www.sciencedirect.com/science/article/pii/S0140700713001783 |
