Artículos de revistas
Structural, microstructural and magnetocaloric investigations in high-energy ball milled Ni2.18Mn0.82Ga powders
Registro en:
Solid State Communications. Pergamon-elsevier Science Ltd, v. 148, n. 41858, n. 289, n. 292, 2008.
0038-1098
WOS:000260907800008
10.1016/j.ssc.2008.09.015
Autor
de Santanna, YVB
de Melo, MAC
Santos, IA
Coelho, AA
Gama, S
Cotica, LF
Institución
Resumen
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) In this paper, structural, microstrucutural and magnetocaloric properties of Ni2.18Mn0.82Ga alloys submitted to high-energy ball milling are reported. A 7-layered orthorhombic martensitic (Pnnm) phase was detected in post-milling annealed samples, which reached a microstrucuture composed predominantly by nanograins. The magnetocaloric effect is strongly weakened in comparison with ascast samples of similar composition. This effect can be attributed to the absence of the mesoscale twin-related martensitic variants in the nanostructurated powders. However, post-milled samples annealed at 1123 K for 4 h present relative cooling powers as high as those observed for manganites. Therefore, these materials can be considered as potential candidates for use as regenerators in prototypal magnetic refrigerators. (C) 2008 Elsevier Ltd. All rights reserved. 148 41858 289 292 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) CNPq [554855/2006-2]