Searching the conditions for a table-like shape of the magnetic entropy in the magnetocaloric LBMO2.98/LBMO2.95 composite
Unité de recherche Matériaux Avancés et Nanotechnologies (URMAN), Higher Institute of Applied Sciences and Technology of Kasserine, Kairouan University, BP 471, 1200, Kasserine, Tunisia
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Accepted: 10 October 2016
Published online: 9 November 2016
The conditions to obtain a table-like behavior of the entropy change, on the composite system , have been investigated from the isothermal magnetic entropy change versus temperature curves of La2/3Ba1/3MnO2.98 and La2/3Ba1/3MnO2.95 materials. The latters are characterized by Curie temperatures () values (310 K for La2/3Ba1/3MnO2.98 and 292 K for La2/3Ba1/3MnO2.95 around room temperature. The temperature dependence of the isothermal magnetic entropy change has been calculated for the composite system with . The optimum magnetocaloric effect (MCE) properties, i.e., a curve with table-like shape, have been found in the temperature interval of 293-309 K for the composite with at 1 T. The of the composite comes close to a constant value of 1.73(7)J/(kg ·K). A large refrigerant capacity value of J/kg is obtained in a wide temperature span over 16 K. This composite can be used as the working material in the Ericsson-cycle magnetic regenerative refrigerator. These results make the system a promising material for practical magnetic refrigeration using a lower field (1 T), which is much easier to generate by permanent magnets, than higher fields, like 2 T.
© Società Italiana di Fisica and Springer-Verlag Berlin Heidelberg, 2016