[article]
Titre : |
Entropy change and kinetic effects at the magnetostructural phase transition of MnBi |
Titre original : |
Changement d'entropie et effets cinétiques à la transition de phase magnétostructurelle de MnBi |
Type de document : |
texte imprimé |
Auteurs : |
Vittorio Basso, Auteur ; Elena Sonia Olivetti, Auteur ; Luca Martino, Auteur |
Année de publication : |
2014 |
Article en page(s) : |
pp. 266–272 |
Note générale : |
Refrigeration |
Langues : |
Anglais (eng) |
Mots-clés : |
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 |
in International journal of refrigeration > Vol. 37 N° 1 (Janvier 2014) . - pp. 266–272
[article] Entropy change and kinetic effects at the magnetostructural phase transition of MnBi = Changement d'entropie et effets cinétiques à la transition de phase magnétostructurelle de MnBi [texte imprimé] / Vittorio Basso, Auteur ; Elena Sonia Olivetti, Auteur ; Luca Martino, Auteur . - 2014 . - pp. 266–272. Refrigeration Langues : Anglais ( eng) in International journal of refrigeration > Vol. 37 N° 1 (Janvier 2014) . - pp. 266–272
Mots-clés : |
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 |
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