Moore, J. D. ; Skokov, K. P. ; Liu, J. ; Gutfleisch, O. (2012)
Procedure for numerical integration of the magnetocaloric effect.
In: Journal of Applied Physics, 112 (6)
doi: 10.1063/1.4754561
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
When the magnetocaloric effect is obtained using indirect or direct techniques, the result is the isothermal entropy change ΔSiso(T,ΔH) or the adiabatic temperature change ΔTad(T,ΔH). Evaluation of the linking relation dTad = −(T/Cp)×dSiso (Cp, specific heat; T, temperature) as a way to determine the magnetocaloric effect, however, is typically not performed because it requires detailed knowledge of Cp(T,H). Here, we outline the procedure for numerical integration of the magnetocaloric effect—this is important for a physics understanding and as a practical guide on implementing the procedure. The process is notably different than the well-known method used to calculate ΔSiso from the Maxwell equation. We test the procedure by using it to calculate Cp (with dTad and dSiso as input data) and comparing it with directly measured Cp, finding excellent agreement for both first-order transition in LaFe11.6Si1.4 and second-order transition in Gd. We establish the merits and limitations of the method. In particular, the presence of a demagnetizing effect in experimental data can reduce accuracy of the method. The procedure can be applied to accurately model the magnetocaloric effect in a magnetic cooling cycle.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2012 |
| Autor(en): | Moore, J. D. ; Skokov, K. P. ; Liu, J. ; Gutfleisch, O. |
| Art des Eintrags: | Bibliographie |
| Titel: | Procedure for numerical integration of the magnetocaloric effect |
| Sprache: | Englisch |
| Publikationsjahr: | 2012 |
| Verlag: | American Institute of Physics |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Journal of Applied Physics |
| Jahrgang/Volume einer Zeitschrift: | 112 |
| (Heft-)Nummer: | 6 |
| DOI: | 10.1063/1.4754561 |
| Kurzbeschreibung (Abstract): | When the magnetocaloric effect is obtained using indirect or direct techniques, the result is the isothermal entropy change ΔSiso(T,ΔH) or the adiabatic temperature change ΔTad(T,ΔH). Evaluation of the linking relation dTad = −(T/Cp)×dSiso (Cp, specific heat; T, temperature) as a way to determine the magnetocaloric effect, however, is typically not performed because it requires detailed knowledge of Cp(T,H). Here, we outline the procedure for numerical integration of the magnetocaloric effect—this is important for a physics understanding and as a practical guide on implementing the procedure. The process is notably different than the well-known method used to calculate ΔSiso from the Maxwell equation. We test the procedure by using it to calculate Cp (with dTad and dSiso as input data) and comparing it with directly measured Cp, finding excellent agreement for both first-order transition in LaFe11.6Si1.4 and second-order transition in Gd. We establish the merits and limitations of the method. In particular, the presence of a demagnetizing effect in experimental data can reduce accuracy of the method. The procedure can be applied to accurately model the magnetocaloric effect in a magnetic cooling cycle. |
| Freie Schlagworte: | demagnetisation, entropy, gadolinium, iron alloys, lanthanum alloys, magnetic cooling, magnetic transitions, Maxwell equations, silicon alloys, specific heat |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Funktionale Materialien 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften |
| Hinterlegungsdatum: | 25 Apr 2013 08:59 |
| Letzte Änderung: | 25 Apr 2013 08:59 |
| PPN: | |
| Sponsoren: | The research leading to these results was funded by the Leibniz “Pakt für Forschung und Innovation” program. |
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