Presentation Information
[P2-17]Magnetothermal and magnetocaloric properties of Er1-xTmxAl2 series compounds
*Paula Ribeiro1, Bruno Alho1, Rodrigo de Oliveira1, Pedro von Ranke1, Eduardo Nóbrega1, Vinicius de Sousa1, Alexandre Carvalho1,2,3, José Luis Affonso1 (1. Rio de Janeiro State University (Brazil), 2. Universidade Federal de São Paulo (Brazil), 3. Universidade Estadual de Maringá (Brazil))
Keywords:
magnetocaloric effect,rare earth,crystalline electrical fiels
The magnetocaloric effect (MCE) was observed at the first time in 1917 by Weiss and Piccard [1] when realized a sizable and reversible temperature change in nickel near its Curie temperature. With the use of these materials, a potential application lies in cooling systems that are foreseen to demand less energy and exhibit a lower environmental impact in comparison to conventional methods [2].
Yang et. al [3] reported a giant conventional MCE in the ferromagnetic series Er(1-x)Tm(x)Al2 upon low magnetic field changes. For this series, the maximum values of isothermal entropy change occur in the Curie temperature interval for the extreme compounds ( and , which is suitable for gas liquefaction. It is mentioned that the Er0.7Tm0.3Al2 and Er0.7Tm0.3Al2 compounds showed, respectively, and , for a magnetic field change of 0 to 2 T. The authors [3] mentioned that Er0.7Tm0.3Al2 could be a high-performance candidate for magnetic cooling at low temperatures between liquid helium and liquid hydrogen temperatures.
In this work we present a theoretical investigation of the magnetothemal and magnetocaloric effect recently reported in the intermetallic series compounds Er1-xTmxAl2. Our model Hamiltonian includes the crystalline electrical field, exchange, and Zeeman interactions in both Er3+ and Tm3+ sublattices. A remarkable agreement was achieved between the theoretical calculations and experimental data concerning heat capacity, and (magnetocaloric quantities). Additionally, the analysis of magnetic anisotropy and simulations for the rotating magnetocaloric effect were performed.
[1] Pierre Weiss and Auguste Piccard. 1917. Le phénomène magnétocalorique. J. Phys. (Paris), 5th Ser. 7: 103-109.
[2] Julia Lyubina, J. Phys. D: Appl. Phys. 50, 053002 (2017).
[3] Shuxian Yang et. al, Journal of Materials Science & Technology 146, 168 (2023).
Yang et. al [3] reported a giant conventional MCE in the ferromagnetic series Er(1-x)Tm(x)Al2 upon low magnetic field changes. For this series, the maximum values of isothermal entropy change occur in the Curie temperature interval for the extreme compounds ( and , which is suitable for gas liquefaction. It is mentioned that the Er0.7Tm0.3Al2 and Er0.7Tm0.3Al2 compounds showed, respectively, and , for a magnetic field change of 0 to 2 T. The authors [3] mentioned that Er0.7Tm0.3Al2 could be a high-performance candidate for magnetic cooling at low temperatures between liquid helium and liquid hydrogen temperatures.
In this work we present a theoretical investigation of the magnetothemal and magnetocaloric effect recently reported in the intermetallic series compounds Er1-xTmxAl2. Our model Hamiltonian includes the crystalline electrical field, exchange, and Zeeman interactions in both Er3+ and Tm3+ sublattices. A remarkable agreement was achieved between the theoretical calculations and experimental data concerning heat capacity, and (magnetocaloric quantities). Additionally, the analysis of magnetic anisotropy and simulations for the rotating magnetocaloric effect were performed.
[1] Pierre Weiss and Auguste Piccard. 1917. Le phénomène magnétocalorique. J. Phys. (Paris), 5th Ser. 7: 103-109.
[2] Julia Lyubina, J. Phys. D: Appl. Phys. 50, 053002 (2017).
[3] Shuxian Yang et. al, Journal of Materials Science & Technology 146, 168 (2023).
