Gd sub(90)Co sub(2.5)Fe sub(7.5) alloy displaying enhanced magnetocaloric properties

• Published in: Journal of alloys and compounds Vol. 622; pp. 1061 - 1067
• Main Authors: Provenzano, V, Shull, R D, Kletetschka, G, Stutzman, P E
• Format: Journal Article
• Language: English
• Published: 15-02-2015
• Subjects: Computation; Entropy; Gadolinium; Iron; Magnetic properties; Refrigeration; Searching; Thermal measurements
• ISSN: 0925-8388
• DOI: 10.1016/j.jallcom.2014.10.169

We report on the discovery of a new Gd sub(90)Co sub(2.5)Fe sub(7.5) alloy exhibiting superior magnetocaloric properties compared to those of gadolinium. We present magnetically-derived entropy change, Delta S sub(M), computed from magnetic data, and thermally-derived temperature change, Delta T sub(ad), obtained from direct thermal measurements together with their respective MCE peaks for the alloy and gadolinium. The MCE peaks of the alloy are taller and broader than the corresponding MCE peaks of gadolinium. Correspondingly, the refrigeration capacity (RC) values of the alloy computed from magnetic and thermal MCEs for field changes, Delta H, of 400 kA/m (0.5 T) and 800 kA/m (1 T) are about 20% larger than those of gadolinium. Two possible mechanisms are proposed to account for the improved magnetocaloric properties of gadolinium alloyed with small amounts of Co and Fe, thereby pointing out a different methodology to use in the search for improved low field magnetic refrigerants.