Influence of short time milling in R-5(Si,Ge)(4), R = Gd and Tb, magnetocaloric materials

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

Autores

Pires, AL (Autor) Outra; Belo, JH (Autor) Outra; Turcaud, J (Autor) Outra; Oliveira, GNP (Autor) Outra; araujo, j. p. (Autor) FCUP; Berenov, A (Autor) Outra; Cohen, LF (Autor) Outra; Lopes, AML (Autor) Outra; pereira, a. m. (Autor) FCUP

Revista

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Título: MATERIALS & DESIGN

Vol. 85

Páginas: 32-38

ISSN: 0264-1275

Indexação

ISI Web of Knowledge - 30 Citações

Scopus - 30 Citações

Outras Informações

ID Authenticus: P-00G-KS5

DOI: 10.1016/j.matdes.2015.06.099

Abstract (EN): The effect of the short milling times on R-5(Si,Ge)(4) R = Gd, Tb magnetocaloric material properties was investigated. In particular, the effect of milling on atomic structure, particles size and morphology, magnetic, and magnetocaloric effect was studied. With short milling times (<2.5 h), a reduction of the Gd5Si1.3Ge2.7 and Tb5Si2Ge2 particles size was achieved down to approximately 3.5 mu m. For both compositions the main differences are a consequence of the milling effect on the coupling of the structural and magnetic transitions. In the Gd5Si1.3Ge2.7 case, a second-order phase transition emerges at high temperatures as a result of ball milling. Consequently, there is a decrease in the magnetocaloric effect of 35% after 150 min of milling. Interestingly, an opposite effect is observed in Tb5Si2Ge2 where a 23% increase of the magnetocaloric effect was achieved, driven by the enhancement of the coupling between magnetic and structural transitions arising from internal strain promoted by the milling process.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 7