Tuning the Magnetocaloric Properties of the La(Fe,Si)13 Compounds by Chemical Substitution and Light Element Insertion

LaFe13−xSix compounds exhibit a giant magnetocaloric effect and they are considered as a good magnetocaloric working substance for an environmentally friendly cooling technique. Nevertheless as the Curie temperature TC is around 200 K, it is necessary to tune TC near room temperature for magnetic refrigeration. In this work we present a review of the various methods of synthesis and shaping of the LaFe13−xSix type compounds as well as the influence of chemical substitution, light element insertion or combination of both on TC, magnetic entropy and adiabatic temperature variation (ΔSM and ΔTad), and stability upon cycling. The advantages and drawbacks of each method of preparation and type of element substitution/insertion are discussed. The implementation of these NaZn13 type materials in active magnetic refrigerator is presented and their performances are compared to that of Gd in prototypes.