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Magnetocaloric effect of an Fe-based metallic glass compared to benchmark gadolinium

Waske, A. and Hermann, H. and Mattern, N. and Skokov, K. and Gutfleisch, O. and Eckert, J. (2012):
Magnetocaloric effect of an Fe-based metallic glass compared to benchmark gadolinium.
In: Journal of Applied Physics, American Institute of Physics, p. 123918, 112, (12), ISSN 00218979,
[Online-Edition: http://dx.doi.org/10.1063/1.4770468],
[Article]

Abstract

We report on the magnetocaloric effect in an Fe-based metallic glass (Fe80B12Nb8) as compared to the benchmark material gadolinium. From temperature-dependent magnetization measurements, the magnetic entropy change was calculated using the thermodynamic Maxwell relations. The adiabatic temperature change was directly measured for both materials using a dedicated setup. An analysis of the magnetic transition in amorphous Fe80B12Nb8 and crystalline gadolinium using a mean field and a phenomenological model was carried out. It was shown that both materials, in particular crystalline gadolinium, which does not possess structural disorder but merely a fluctuation of the exchange integral, can be described using the Handrich model for the magnetic transition of disordered materials. Furthermore, the Landau theory of second-order phase transitions quantitatively describes the magnetic entropy change and its dependence on the applied field very well for both materials with different definitions of disorder.

Item Type: Article
Erschienen: 2012
Creators: Waske, A. and Hermann, H. and Mattern, N. and Skokov, K. and Gutfleisch, O. and Eckert, J.
Title: Magnetocaloric effect of an Fe-based metallic glass compared to benchmark gadolinium
Language: English
Abstract:

We report on the magnetocaloric effect in an Fe-based metallic glass (Fe80B12Nb8) as compared to the benchmark material gadolinium. From temperature-dependent magnetization measurements, the magnetic entropy change was calculated using the thermodynamic Maxwell relations. The adiabatic temperature change was directly measured for both materials using a dedicated setup. An analysis of the magnetic transition in amorphous Fe80B12Nb8 and crystalline gadolinium using a mean field and a phenomenological model was carried out. It was shown that both materials, in particular crystalline gadolinium, which does not possess structural disorder but merely a fluctuation of the exchange integral, can be described using the Handrich model for the magnetic transition of disordered materials. Furthermore, the Landau theory of second-order phase transitions quantitatively describes the magnetic entropy change and its dependence on the applied field very well for both materials with different definitions of disorder.

Journal or Publication Title: Journal of Applied Physics
Volume: 112
Number: 12
Publisher: American Institute of Physics
Uncontrolled Keywords: amorphous state, boron alloys, entropy, exchange interactions (electron), iron alloys, Landau levels, magnetic transitions, magnetisation reversal, magnetocaloric effects, metallic glasses, niobium alloys, thermodynamics
Divisions: 11 Department of Materials and Earth Sciences > Material Science > Functional Materials
11 Department of Materials and Earth Sciences > Material Science
11 Department of Materials and Earth Sciences
Date Deposited: 25 Apr 2013 09:13
Official URL: http://dx.doi.org/10.1063/1.4770468
Identification Number: doi:10.1063/1.4770468
Funders: This work was funded by the Leibniz Society.
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