Achieving table-like magnetocaloric effect and large refrigerant capacity around room temperature in Fe78−xCexSi4Nb5B12Cu1 (x=0–10) composite materials

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Fully amorphous Fe 78− x Ce x Si 4 Nb 5 B 12 Cu 1 ( x =0, 1, 3, 5 and 10) alloy ribbons were prepared by melt-spinning. With partial substitution of Ce for Fe, the Curie temperature could be tuned in a large temperature range from 465 to 281 K and the maximum magnetic entropy change (−Δ S M ) for a field change from 0 to 5 T decreased from 3.25 to 2.18 J/kg K. Two types of composite materials with varied Ce contents were obtained by assembling the ribbons layer by layer or mixing the powders with various Ce contents. A table-like magnetocaloric effect (MCE) was observed in these composites. The −Δ S M of the composites approach a nearly constant value of ~2.0 J/kg K for a field change of 0–5 T in a wide temperature span over 80 K, resulting in large refrigerant capacity values, >370 J/kg. These composites can be used as the working material in an active magnetic regenerative refrigerator around room temperature. • Amorphous Fe 78− x Ce x Si 4 Nb 5 B 12 Cu 1 ( x =0–10) alloys were obtained by melt-spinning. • Multilayer and powder composites with x =1, 3, 5 and 10 were prepared. • The (−Δ S M ) of the composites approach a nearly constant value (~2J/kg K, Δ μ 0 H =5 T). • Table-like (−Δ S )− T curves of the composites result in large Δ T FWHM and RC values. • The composites are good candidates for the MCMs working around room temperature.