Improvement of low-field magnetic entropy change by increasing Fe concentration in solid-state reactive sintered La(FexSi1−x)13

• La(FexSi1−x)13 specimens were fabricated by the solid-state reaction sintering.
• Their Fe content is confirmed to be x ⩾ 0.90 by energy dispersion X-ray analysis.
• Magnetic entropy change of -24 J/kg K is evaluated under 0.6 T for x = 0.91.
• Low-field entropy change is remarkably improved by increasing the Fe concentration.

Solid-state reactive sintering has been carried out in order to fabricate La(FexSi1−x)13 specimens with a higher Fe concentration. No trace of α-Fe was confirmed for x = 0.90, while a residual amount of α-Fe less than 0.6 vol.% was observed for x = 0.91. The net value of the Fe concentration for the La(FexSi1−x) phase in both specimens is confirmed to be close to the nominal value based on the energy dispersion X-ray analyses. Magnetic entropy changes ΔSM = –23 and –24 J/kg K is obtained even under the low field change of 0.6 T for x = 0.90 and 0.91, respectively. Therefore, the low field response of ΔSM is improved owing to an increase in the net value of the Fe concentration in La(FexSi1−x) by the sintering method.