Microstructure and Magnetocaloric Effect by Doping C in La-Fe-Si Ribbons

The melt-spun ribbons of LaFe(11.5)Si(1.5)C(x) (x = 0, 0.1, 0.2, 0.3) compounds are prepared by the melt fast-quenching method. The doping of C is beneficial to the nucleation and precipitation of the La (Fe, Si)(13) phase, which is indicated by the microstructure observation and the elemental analysis. Subsequently, the ribbons of LaFe(11.5)Si(1.5)C(0.2) are annealed at different times, and the phase composition, the microstructures, and the magnetic properties are investigated. The LaFe(11.5)Si(1.5)C(0.2) ribbons annealed at 1273 K for 2 h achieved the best magnetic properties, and the maximum isothermal magnetic entropy change with a value of 9.45 J/(kg·K) upon an applied field of 1.5 T at an increased Curie temperature 255 K.