Magnetocaloric effect in La0.7Ca0.3MnO3 nanotube arrays with broad working temperature span

• Tipo: Artigo em Revista Científica Internacional
• Data: 2015

Autores

Kumaresavanji, M (Autor) Outra; Sousa, CT (Autor) FCUP; Pires, A (Autor) Outra; pereira, a. m. (Autor) FCUP; Lopes, AML (Autor) Outra; araujo, j. p. (Autor) FCUP

Revista

Título: Journal of Applied Physics

Vol. 117

Página Final: 104304

ISSN: 0021-8979

Editora: American Institute of Physics

Indexação

ISI Web of Knowledge - 11 Citações

Scopus - 10 Citações

Outras Informações

ID Authenticus: P-00A-8DQ

DOI: 10.1063/1.4914410

Abstract (EN): We have studied the magnetic entropy change of highly ordered La0.7Ca0.3MnO3 nanotube arrays synthesized by template assisted sol-gel method in temperatures ranging from 179 to 293K and in magnetic fields up to 5 T. From the measurements of isothermal magnetization, we have calculated the maximum isothermal magnetic entropy change of -Delta S-M = 1.9 J/kgK around the Curie temperature at 236K for a field of 5 T. The nanotubes present lower magnetic entropy change compared with their bulk counterpart (-Delta S-M = 4.8 J/kg K) which was prepared by the same sol-gel route. Such diminished magnetic entropy change observed in nanotubes is explained by the disordered magnetic states which are created on the surface sites of nanograins due to the larger surface to volume ratio. However, the nanotubes present an expanded magnetic transition that extends over a wide temperature range and suggest that such manganite nanotubes could be used for magnetic refrigeration with broad working temperature span. (C) 2015 AIP Publishing LLC.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 6