Ferrite multiphase/carbon nanotube composites sintered by spark plasma sintering

Abstract

Ni-Carbon nanotube (CNT)-Ni_0.5Zn_0.5Fe₂O₄ multiphase composites were sintered by spark plasma sintering (SPS) technique. Ni nanoparticles were in-situ formed due to the localized carbothermal reduction by CNTs and well distributed between grain boundaries in the composites. The electrical conductivity of the resultant multiphase composites was strongly dependent on the weight percentage of CNTs. In the SPS process, CNTs acted as “heating source” and improved the consolidation of the composites. The results indicate that the introduction of the CNTs can promote the sintering kinetics of the ferrite ceramics. However, the grain growth kinetics has been inhibited by SPS and the grain size becomes finer.