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

• Type: Article in International Scientific Journal
• Date: 2015

Authors

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

Journal

The Journal is awaiting validation by the Administrative Services.

Title: MATERIALS & DESIGN

Vol. 85

Pages: 32-38

ISSN: 0264-1275

Indexing

ISI Web of Knowledge - 30 Citations

Scopus - 30 Citations

Other information

Authenticus ID: 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7