Partager

Document IIF

Une méthode rapide pour évaluer l'effet magnétocalorique dans les composés de MnFe(P,As) de premier ordre.

A fast method to evaluate magnetocaloric effect in first-order MnFe(P,As) compounds.

Auteurs : ZHANG L., ASTEN D. van, SEELER F., et al.

Résumé

The magnetocaloric effect is measured by isothermal entropy change and adiabatic temperature change. Both quantities can be derived from the heat capacity measurement in different magnetic fields. The conventional semi-adiabatic or relaxation methods of measuring heat capacity are time consuming and not very suitable for materials with first order transition. The differential scanning calorimetry (DSC) has been proven to be a more robust method. But a DSC in a magnetic field is not readily available. The authors propose here a method to evaluate the magnetocaloric effect in first-order MnFe(P,As) compounds, using a commercial DSC instrument coupled with magnetic measurements. The heat capacity of MnFe(P,As) exhibits a peak at transition. The baseline and peak shape remain almost unchanged in magnetic fields. The peak temperature displays a shift with a linear dependence on magnetic field. This field dependence can be determined by measuring temperature dependence of magnetization in different magnetic fields. Therefore, the heat capacity in magnetic fields can be obtained by shifting the peak measured in zero field. The isothermal entropy change obtained using this method in MnFe(P,As) compounds shows good agreement with that from magnetization isotherms. Furthermore, this method avoids complication introduced by demagnetization field when measuring heat capacity on a plate-like sample in magnetic fields and domain effect in magnetization isotherms.

Documents disponibles

Format PDF

Pages : 2010-4

Disponible

  • Prix public

    20 €

  • Prix membre*

    Gratuit

* meilleur tarif applicable selon le type d'adhésion (voir le détail des avantages des adhésions individuelles et collectives)

Détails

  • Titre original : A fast method to evaluate magnetocaloric effect in first-order MnFe(P,As) compounds.
  • Identifiant de la fiche : 2011-0170
  • Langues : Anglais
  • Source : 4th International Conference on Magnetic Refrigeration at Room Temperature (Thermag IV). Proceedings: Baotou, China, August 23-27, 2010.
  • Date d'édition : 23/08/2010

Liens


Voir d'autres communications du même compte rendu (54)
Voir le compte rendu de la conférence

Indexation