Magnetism and magnetic entropy change in LaFe₁₁Al₂C_x compounds around room temperature

Magnetism and magnetic entropy changes in LaFe_11Al_2C_x (x=0.0, 0.2 and 0.5) compounds have been investigated. The Curie temperature T_\rm C is conveniently controlled from 200K to room temperature by varying the carbon concentration. Large magnetic entropy change is obtained over a wide temperature range due to the high magnetization and the drastic decrease in the magnetization around T_\rm C. The large magnetic entropy change in wide temperature range, low cost and the convenience of controlling T_\rm C suggest that the LaFe_11Al_2C_x compounds are promising candidates for magnetic refrigerants in the corresponding temperature range.