Gd3Fe4Si Alloy for Magnetic Refrigeration Application in a Wide Temperature Range

• Published in: Journal of superconductivity and novel magnetism Vol. 30; no. 8; pp. 2283 - 2290
• Main Authors: T. P., Rashid, Curlik, Ivan, Ilkovic, Sergej, Reiffers, Marian, Nagalakshmi, R.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-08-2017
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Magnetic Materials; Magnetism; Original Paper; Physics; Physics and Astronomy; Strongly Correlated Systems; Superconductivity; X-ray diffraction; Magnetic material; Magnetocaloric effect; Refrigerant capacity; Intermetallic compound; Alloys
• ISSN: 1557-1939; 1557-1947
• DOI: 10.1007/s10948-017-4031-7

Gd
3
Fe
4
Si alloy prepared by the arc melting method crystallizes in Mn
5
Si
3
-type hexagonal Gd
5
Si
3
, LaNi
2
-type cubic GdFe
2
, and hexagonal Gd phases. Magnetization and heat capacity measurements performed on the Gd
3
Fe
4
Si alloy reveal the occurrence of four second-order magnetic transitions having ordering temperatures at
T
1
= 57 K,
T
2
= 72 K,
T
3
= 225 K and
T
4
= 295 K. The multiple magnetic transitions offer interesting magnetocaloric effect (MCE) in this compound. Non-saturation behaviour of magnetization versus field isotherm at 4 K (even at 9 T magnetic fields) suggests the existence of competing ferro- and antiferromagnetic interactions in the compound. The magnetic entropy change (−Δ
S
M
) associated with these multiple magnetic transitions is calculated from isothermal magnetization data using Maxwell equations. The MCE spreads over a wide span of temperature viz, Δ
T
= 257 K possessing a refrigerant capacity (RC) of 205 J/kg (for a magnetic field change of 0–5 T) with no thermal or magnetic hysteresis. This value of RC is nearly the same as that of the reference giant magnetocaloric material Gd
5
Ge
2
Si
2
under the same condition. Hence, the wide temperature range MCE (including room temperature) of this material may be the result of multiple magnetic transitions.