Liu, Wei ; Scheibel, Franziska ; Fortunato, Nuno M. ; Dirba, Imants ; Gottschall, Tino ; Zhang, Hongbin ; Skokov, Konstantin P. ; Gutfleisch, Oliver (2024)
Role of Debye temperature in achieving large adiabatic temperature changes at cryogenic temperatures: a case study on Pr2In.
In: Physical Review B, 109 (14)
doi: 10.1103/PhysRevB.109.L140407
Artikel, Bibliographie

Kurzbeschreibung (Abstract)

The excellent magnetic entropy change (ΔST) in the temperature range of 20 ∼ 77 K due to the first-order phase transition makes Pr2In an intriguing candidate for magnetocaloric hydrogen liquefaction. As an equally important magnetocaloric parameter, the adiabatic temperature change (ΔTad) of Pr2In associated with the first-order phase transition has not yet been reported. In this work, the ΔTad of Pr2In is obtained from heat capacity measurements: 2 K in fields of 2 T and 4.3 K in fields of 5 T. While demonstrating a ΔTad that is not as impressive as its remarkable ΔST, Pr2In exhibits a low Debye temperature (TD) of around 110 K. Based on these two observations, an approach that combines the mean-field and Debye models is developed to study the correlation between ΔTad, one of the most important magnetocaloric parameters, and TD, one important property of a material. The role of TD in achieving large ΔTad is revealed: materials with higher TD tend to exhibit larger ΔTad, particularly in the cryogenic temperature range. This discovery explains the absence of an outstanding ΔTad in Pr2In and can serve as a tool for designing or searching for materials with both a large ΔST and a ΔTad.

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