Rapidly Solidified La(Fe Si ) Alloys and Their Magnetocaloric Properties

La(Fe_1-xSi_x)₁₃ alloys with the NaZn₁₃-type structure were prepared from rapidly solidified ribbons via a short annealing treatment. The rapid solidification process was realized by a laboratory scale melt-spinning apparatus and a large strip-casting facility. The rapidly solidified ribbons contained a large amount of the NaZn₁₃-type phase together with an alpha-(Fe-Si) phase and a La-rich phase, which would readily combine to form the NaZn₁₃-type phase upon a short-time annealing. The magnetic part of the entropy change near the Curie temperature at about 190 K was estimated from magnetization versus temperature measurements to be about -20 J/K/kg for a field change between zero and one T. The process developed in this work can be applied to a mass production of La(Fe_1-xSi_x)₁₃ as the starting material for production of hydrogenated La(Fe_1-xSi _x)₁₃ H_x for near-room-temperature magnetic refrigeration