The influences of carbon on phase formation, Curie temperature, and magnetic entropy change of the NaZn13-type LaFe11.7Si1.3 were investigated. Seven carbon-containing alloys, LaFe11.7Si1.3Cx with x = 0, 0.03, 0.06, 0...The influences of carbon on phase formation, Curie temperature, and magnetic entropy change of the NaZn13-type LaFe11.7Si1.3 were investigated. Seven carbon-containing alloys, LaFe11.7Si1.3Cx with x = 0, 0.03, 0.06, 0.10, 0.20, 0.30, and 0.50, respectively, were prepared for this investigation. Experimental results show that addition of a small amount of carbon in LaFe11.7Sil.3 is favorable for the formation of the NaZn13-type structure of LaFe11.7Si1.3Cx. The lattice constant increases with C addition and x increases in the alloy because of the introduction of C as interstitial atoms. The Curie temperature of LaFe11.7Si1.3Cx increases from 194 K to 225 K as x increases from 0 to 0.5. Large magnetic entropy changes were observed in these carbon-containing alloys LaFe11.7Si1.3Cx because of their first-order structural/magnetic transition. The maximum magnetic entropy change of 27.5 J.kg^-1K^-1 at 202 K for the 0-1.56 T magnetic field change was observed in the alloy with x = 0.06. The large magnetic-entropy changes corresponding to low magnetic field change, and the low cost of the material of LaFe11..7Si1.3Cx makes it a promising candidate to be used as magnetic refrigerants in the corresponding temperature range.展开更多
基金The study was financially supported by the National Natural Science Foundation of China (Nos. 50371058 and 50471108)
文摘The influences of carbon on phase formation, Curie temperature, and magnetic entropy change of the NaZn13-type LaFe11.7Si1.3 were investigated. Seven carbon-containing alloys, LaFe11.7Si1.3Cx with x = 0, 0.03, 0.06, 0.10, 0.20, 0.30, and 0.50, respectively, were prepared for this investigation. Experimental results show that addition of a small amount of carbon in LaFe11.7Sil.3 is favorable for the formation of the NaZn13-type structure of LaFe11.7Si1.3Cx. The lattice constant increases with C addition and x increases in the alloy because of the introduction of C as interstitial atoms. The Curie temperature of LaFe11.7Si1.3Cx increases from 194 K to 225 K as x increases from 0 to 0.5. Large magnetic entropy changes were observed in these carbon-containing alloys LaFe11.7Si1.3Cx because of their first-order structural/magnetic transition. The maximum magnetic entropy change of 27.5 J.kg^-1K^-1 at 202 K for the 0-1.56 T magnetic field change was observed in the alloy with x = 0.06. The large magnetic-entropy changes corresponding to low magnetic field change, and the low cost of the material of LaFe11..7Si1.3Cx makes it a promising candidate to be used as magnetic refrigerants in the corresponding temperature range.
