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Structural study and large magnetocaloric entropy change at room temperature of La1−xxMnO3 compounds

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submitted on 2024-05-20, 04:58 and posted on 2024-05-20, 04:58 authored by C. Henchiri, T. Mnasri, A. Benali, R. Hamdi, E. Dhahri, M. A. Valente, B. F. O. Costa

In this study, our central focus is to investigate the magnetocaloric characteristics of a La1−x□xMnO3 (x = 0.1, 0.2 and 0.3) series prepared by a sol–gel technique published in Prog. Mater. Sci., 93, 2018, 112–232. The crystallographic study revealed that our compounds crystallize in a rhombohedral structure with Rc. Ferromagnetic (FM) and paramagnetic (PM) characters were detected from the variation in magnetization as a function of magnetic fields at different temperatures. The second order transition was verified from the Arrott plots (M2 vs. (μ0H/M)), where the slopes have a positive value. In order to verify the second order, we traced the variation of magnetization vs. temperature at different magnetic fields for x = 0.2. This revealed a ferromagnetic (FM)–paramagnetic (PM) transition when temperature increases. Relying on the indirect method while using the Maxwell formula, we determined the variation in the entropy (−ΔSM) as a function of temperature for different magnetic fields for the three samples. We note that all the studied systems stand as good candidates for magnetic refrigeration with relative cooling power (RCP) values of around 131.4, 83.38 and 57.26 J kg−1 with magnetic fields below 2 T, respectively. Subsequently, the magnetocaloric effect was investigated by a phenomenological model for x = 0.2. The extracted data confirm that this phenomenological model is appropriate for the prediction of magnetocaloric properties. The study also demonstrated that this La0.8□0.2MnO3 system exhibits a universal behaviour.

Other Information

Published in: RSC Advances
License: http://creativecommons.org/licenses/by-nc/3.0/
See article on publisher's website: http://dx.doi.org/10.1039/c9ra10469k

History

Language

  • English

Publisher

Royal Society of Chemistry

Publication Year

  • 2020

License statement

This Item is licensed under the Creative Commons Attribution-NonCommercial 3.0 Unported International License.

Institution affiliated with

  • Hamad Bin Khalifa University
  • College of Health and Life Sciences - HBKU