Significant magnetocaloric and microwave absorption performances in ultrafine ErC2@C core-shell structural nanocomposites

Abstract Traditional techniques for synthesizing ultrafine rare earth carbide particles involving high-temperature annealing processes are lack of effectiveness, resulting in an extreme limitation to fully explore their properties and potential applications. We herein demonstrate a modified arc-discharging approach to synthesize the core/shell structural ErC 2 @C nanoparticles, in which ultrafine ErC 2 clusters with a mean diameter of 7.5 ± 0.5 nm can be uniformly dispersed in carbon matrix ascribed to the non-equilibrium evaporation-condensation process. It is found that the ErC 2 @C nanoparticles present significant magnetocaloric and microwave absorption performances, corresponding to the magnetic entropy change of 8.7 J/kgK at 4 K with the magnetic field variation of 0–5 T, and the maximum reflection loss of −49 dB at 15 GHz for a 2.44 mm thick absorber. The present work thus provides an effective strategy for the synthesis of rare earth carbides and explores their potential applications in diverse fields.