LaFe 13-xSi x compounds with x=2.4, 2.6, and 2.8 have been carefully prepared and characterized. X-ray powder diffraction patterns confirm that the samples crystallize in a single NaZn 13-type phase. Magnetic measurements were carried out in a SQUID magnetometer. The Curie temperature T c of LaFe 13-xSi x samples decreases nearly 50 K with x increasing from 2.4 to 2.8. Around T c the samples exhibit a typical second-order phase transition; and no trace of first-order itinerant electron metamagnetic transition is found. So it is reliable to characterize the magnetic entropy change around T c using magnetic measurement. The maximum values of the magnetic entropy change of LaFe 13-xSi x samples are found to be, at their Curie temperatures, 5.85, 5.9, and 3.7 J/kg.K for x=2.4, 2.6, and 2.8 under a field change of 5 T (0-5 T). For the quite large magnetic entropy change over a wide temperature range, LaFe 13-xSi x compounds appear, therefore, to be a potential material candidate for magnetic cooling.
ASJC Scopus subject areas
- Physics and Astronomy(all)