Preparation and characterization of NiFe bimetallic micro-particles and its composite with silica shell

Publication date: Available online 8 June 2019Source: Journal of Saudi Chemical SocietyAuthor(s): Yan Liu, Xiaoyi ShenAbstractMagnetic NiFe particles were synthesized through hydrothermal method using hydrazine as reductant. Composite particles with core-shell structure were further achieved by depositing silicon dioxide generated via carbonation decomposition of sodium silicate solution on the surface of magnetic cores. Characterized by XRD, the Ni9Fe particles are of fcc-type structure, and the structure of magnetic cores in composite particles was maintained despite being covered by SiO2 shell. The existence of SiO2 shells in the composite particles were demonstrated by SEM, EDS and IR. The results from TG and VSM indicated that the shell structure affected the physiochemical properties. The composite particles exhibited remarkable resistance to oxidation in comparison with Ni9Fe particles due to being protected by SiO2 shell. Meanwhile, both of them are soft magnetic materials, but Ms, Mr and Hc in Ni9Fe@SiO2 particle decreased compared with magnetic NiFe particles. The formation mechanisms of Ni9Fe micro-particles and composite Ni9Fe particles were discussed.Graphical abstractMagnetic NiFe particles with strawberry-like structure were synthesized and protected by coating silca shell. The formation mechanisms of strawberry-like Ni9Fe particles and composite Ni9Fe particles were discussed.
Source: Journal of Saudi Chemical Society - Category: Chemistry Source Type: research