Share

IIR document

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

Author(s) : ZHANG L., ASTEN D. van, SEELER F., et al.

Summary

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.

Available documents

Format PDF

Pages: 2010-4

Available

  • Public price

    20 €

  • Member price*

    Free

* Best rate depending on membership category (see the detailed benefits of individual and corporate memberships).

Details

  • Original title: A fast method to evaluate magnetocaloric effect in first-order MnFe(P,As) compounds.
  • Record ID : 2011-0170
  • Languages: English
  • Source: 4th International Conference on Magnetic Refrigeration at Room Temperature (Thermag IV). Proceedings: Baotou, China, August 23-27, 2010.
  • Publication date: 2010/08/23

Links


See other articles from the proceedings (54)
See the conference proceedings

Indexing