Large magnetocaloric effect in EuGd2O4 and EuDy2O4
| Autor: | Yukio Hinatsu, Yoshihiro Doi, Marco Evangelisti, Elias Palacios, J. J. Romero, Regino Sáez-Puche |
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| Přispěvatelé: | Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Comunidad de Madrid, Gobierno de Aragón |
| Rok vydání: | 2022 |
| Předmět: |
Phase transition
Materials science Condensed matter physics Mechanical Engineering Metals and Alloys Magnetically ordered materials Gadolinium gallium garnet Rare-earth alloys and compounds Magnetocalori Magnetic measurements Calorimetry Heat capacity Ion Condensed Matter::Materials Science chemistry.chemical_compound Magnetic anisotropy Magnetization chemistry Mechanics of Materials Materials Chemistry Magnetic refrigeration Derivative (chemistry) |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| ISSN: | 0925-8388 |
| DOI: | 10.1016/j.jallcom.2021.161847 |
| Popis: | Magnetization, heat capacity and direct measurements of the magnetocaloric effect show that EuGd2O4 and EuDy2O4 have a remarkably large magnetocaloric effect at cryogenic temperatures, owing to their high magnetic density and low ordering temperatures. The Gd derivative orders antiferromagnetically at TN = 4.6 K, while its magnetocaloric effect largely exceeds that of the reference refrigerant Gadolinium Gallium Garnet (GGG) above 5 K. The Dy derivative undergoes two phase transitions at TC1 = 3.65 K and TC2 = 4.7 K, respectively, which are the result of a peculiar magnetic arrangement: the first Dy sublattice is parallel to the crystallographic c-axis, while the Eu sublattice makes a variable angle from 0o to 45o with the direction of the second Dy sublattice that lies in the ab-plane. EuDy2O4 has a lower magnetocaloric effect than EuGd2O4, yet larger than GGG. Both ordering mechanisms are semi-quantitatively explained within the frame of a mean-field simulation, which takes into account the magnetic anisotropy strength of the participating magnetic ions. This work has been funded by Spanish Ministry of Science and Innovation (Projects MAT2017–86019-R, MAT2017–84385-R, RTI2018–098537-B-C22), Gobierno de Aragón (Consolidated Group E11_20R) and Comunidad de Madrid (Project S2009/PPQ-1626). |
| Databáze: | OpenAIRE |
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