Structural, Magnetic and Magnetocaloric Properties of High-Energy Ball-Milled Gd5Si2Ge2B0.05 Alloy
- 65 Downloads
Structural, magnetic and magnetocaloric properties of Gd5Si2Ge2B0.05 alloy, ball milled for different time intervals in the range of 2–50 h were studied. The x-ray powder diffraction analysis of the alloy prior to milling revealed the presence of mixed orthorhombic and monoclinic phases at room temperature. For a milling duration up to 15 h, the alloy powder displayed crystalline nature. Upon further milling, the alloy powder started to lose the crystallinity and after 50 h of milling, the alloy powder displayed amorphous nature. The average particle size of milled samples was found to decrease with increase in milling time. The saturation magnetization value of the bulk alloy 80 emu/g was found to decrease with increase in milling time due to structural disorder. The transition temperature of the milled alloy powder was found to be around 295 K and the transition was found to become broader with increase in milling time. A maximum isothermal entropy change (ΔSmax) of ∼12 J/kg K was obtained in bulk alloy. For a milling duration of 2 h, a marginal decrease of ΔSmax (∼11 J/kg K) was obtained. Whereas, for higher milling durations, (≥ 15 h) a significant decrease in ΔSmax values were observed. However, the broad operating temperature range of the milled powders can be exploited for magnetic refrigeration applications.
KeywordsGd–Si–Ge alloys Structural and magnetic transitions Magnetocaloric effect
First author Dr. N. Pavan Kumar thanks DST-SERB for sanctioning a project under Young Scientist Scheme (File No. YSS/2015/000977).
- 2.Sahlot, M., Riffat, S.B.: Int. J Low-Carbon Tech. 11, 489 (2016)Google Scholar
- 5.Beckmann, O., Lundgren, L.: Hand book of magnetic materials vol 6, (1991) 181 ed K H J Buschow (Amsterdam)Google Scholar
- 17.Barsan, V., Lungu, R.P.: Trends in electromagnetism—from fundamentals to applications. ISBN 978-953-51-0267-0 (2012)Google Scholar