Polycrystalline ErCu2 compound has been prepared by arc melting in inert atmosphere and its magnetic and magnetocaloric properties have been studied. ErCu2 orders antiferromagnetically at TN ~ 11 K. A field induced metamagnetic transition is observed in a field of ~8.5 kOe at 5 K which leads to saturation in magnetization to a value of max 8.4 μB/f.u. The maximum isothermal magnetic entropy change, -ΔSmmax, value of this compound is obtained as 14.9 J/kg K for 50 kOe field change. Corresponding refrigeration capacity and relative cooling power values are 334 J/kg and 412 J/kg, respectively. These values are higher than that for HoCu2 and DyCu2 compounds because the temperature dependent isothermal magnetic entropy change curve of this ErCu2 compound is considerably broader. © 2017 Author(s).

R. Nirmala

Department Of Physics

R. Rajivgandhi

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Magnetic and magnetocaloric properties of the intermetallic compound ErCu2

AIP Conference Proceedings

In this work, magnetic and magnetocaloric properties of melt-spun RCu2 (R = Gd, Tb, Dy, Ho and Er) compounds have been studied. The melt-spun samples have formed in the same orthorhombic crystal structure (space group Imma, no. 74) as that of the arc-melted samples but with a development of crystallographic texture and micron-size grains. The melt-spun ribbons of RCu2 (R = Gd, Tb, Dy, Ho and Er) order antiferromagnetically at 43 K, 51 K, 28 K, 10 K and 11 K (TN) respectively. The ordering temperatures are almost the same as that of the arc-melted samples. The RCu2 compounds show one or more field induced transitions below TN. Therefore, a normal magnetocaloric effect is observed in these compounds when the magnetic field change is larger than the metamagnetic critical field and inverse magnetocaloric effect is observed for smaller field changes. The microgranularity does not seem to smear out the metamagnetic transition. The maximum of isothermal magnetic entropy change, ΔSmmax, is about −2.1 Jkg−1K−1, -5.5 Jkg−1K−1, -5.2 Jkg−1K−1, -17.2 Jkg−1K−1 and -11.7 Jkg−1K−1 respectively for the melt-spun RCu2 (R = Gd, Tb, Dy, Ho and Er) samples for 50 kOe field change. The refrigeration capacity is found to be 40 Jkg-1, 160 Jkg-1, 166 Jkg-1, 230 Jkg-1 and 207 Jkg-1 respectively, for the above samples. These values are nearly the same as that of the arc-melted counterparts. Thus the large magnetocaloric effect in the temperature range of 10 K–70 K make these melt-spun RCu2 samples potential materials for low temperature refrigeration applications. The results also ascertain melt-spinning process as an alternate technique for the production of magnetocaloric alloys and intermetallics. © 2019 Elsevier B.V.

Journal of Alloys and Compounds

Preservation of large low temperature magnetocaloric effect in metamagnetic intermetallic compounds RCu2 (R = Gd, Tb, Dy, Ho and Er) upon rapid solidification

Journal	Data powered by TypesetAIP Conference Proceedings
Publisher	Data powered by TypesetAmerican Institute of Physics Inc.
ISSN	0094243X
Open Access	No