Cs2NaAl1-xCrxF6: A family of compounds presenting magnetocaloric effect

• Autor(a) principal: Pedro, S. S.
• Data de Publicação: 2014
• Outros Autores: Tedesco, J. C. G., Yokaichiya, F., Brandao, P., Gomes, A. M., Landsgesell, S., Pires, M. J. M., Sosman, L. P., Mansanares, A. M., Reis, M. S., Bordallo, H. N.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/19603
• topic: CS2NAALF6 SINGLE-CRYSTALS; MAGNETIC REFRIGERATION; CR3+ IONS; CS2NAGAF6 CRYSTALS; OPTICAL-PROPERTIES; SPECTROSCOPY; ELPASOLITES; RESONANCE; FIELD

In this paper we explore the magnetocaloric effect (MCE) of chromium-doped elpasolite Cs2NaAl1-x,CrxF6 (x = 0.01 and 0.62) single crystals. Magnetization and heat capacity data show the magnetocaloric potentials to be comparable to those of garnets, perovskites, and other fluorides, producing magnetic entropy changes of 0.5 J/kg K (x = 0.01) and 11 J/kg K (x = 0.62), and corresponding adiabatic temperature changes of 4 and 8 K, respectively. These values are for a magnetic field change of 50 kOe at a temperature around 3 K. A clear Schottky anomaly below 10 K, which becomes more apparent when an external magnetic field is applied, was observed and related to the splitting of the Cr3+ energy levels. These results hint at a new family of materials with potential wide use in cryorefrigeration.