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Hysteresis Design of Magnetocaloric Materials—From Basic Mechanisms to Applications
Author(s) -
Scheibel Franziska,
Gottschall Tino,
Taubel Andreas,
Fries Maximilian,
Skokov Konstantin P.,
Terwey Alexandra,
Keune Werner,
Ollefs Katharina,
Wende Heiko,
Farle Michael,
Acet Mehmet,
Gutfleisch Oliver,
Gruner Markus E.
Publication year - 2018
Publication title -
energy technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 44
eISSN - 2194-4296
pISSN - 2194-4288
DOI - 10.1002/ente.201800264
Subject(s) - magnetic refrigeration , materials science , adiabatic process , hysteresis , condensed matter physics , magnetic hysteresis , magnetic field , phase transition , thermodynamics , entropy (arrow of time) , inverse , magnetization , physics , mathematics , quantum mechanics , geometry
Magnetic refrigeration relies on a substantial entropy change in a magnetocaloric material when a magnetic field is applied. Such entropy changes are present at first‐order magnetostructural transitions around a specific temperature at which the applied magnetic field induces a magnetostructural phase transition and causes a conventional or inverse magnetocaloric effect (MCE). First‐order magnetostructural transitions show large effects, but involve transitional hysteresis, which is a loss source that hinders the reversibility of the adiabatic temperature change Δ T ad . However, reversibility is required for the efficient operation of the heat pump. Thus, it is the mastering of that hysteresis that is the key challenge to advance magnetocaloric materials. We review the origin of the large MCE and of the hysteresis in the most promising first‐order magnetocaloric materials such as Ni–Mn‐based Heusler alloys, FeRh, La(FeSi) 13 ‐based compounds, Mn 3 GaC antiperovskites, and Fe 2 P compounds. We discuss the microscopic contributions of the entropy change, the magnetic interactions, the effect of hysteresis on the reversible MCE, and the size‐ and time‐dependence of the MCE at magnetostructural transitions.