摘要

LaFe 11.85 Si 1.15 ribbons with large magnetic entropy change and minor magnetic hysteresis were prepared by a melt-spinning technique followed by heat treatment. The influences of different heat treatment processes on phase constitution, microstructure evolution, magnetic entropy change, Curie temperature and itinerant electron metamagnetic transitions were investigated. The results show that the annealing time has a great influence on the content of 1: 13 phase and magnetocaloric effect. For LaFe 11.85 Si 1.15 alloy annealed at 1050oC for 10 h, the maximum magnetic entropy change (△S M ) value of 20.54 J?kg -1 ?K -1 and the refrigerating capacity (R C ) of 417.21 J?kg -1 can be acquired due to the high content of 1:13 phase in the magnetic field of 0~5 T, and the obvious itinerant electron metamagnetic transition can be observed. The shorter annealing time is not beneficial to the formation of 1:13 phase. However, too long annealing time leads to the decomposition of 1:13 phase and the increase of α-Fe phase.