Effect of surfactant additive on barium hexaferrite nanoparticles synthesized using coprecipitation

Barium hexaferrite nanoparticle have been prepared by co-precipitation method using aqueous solutions of chloride precursors with molar ratio of Fe /Ba -10. To investigate the role of surfactant and its mechanism in this process, coprecipitation was done, in the presence and absence of organic surfactants (CTAB, SDS, Triton X-100 and AOT). After co-precipitation of barium and iron ions using a 5M sodium hydroxide, washing, drying and calcination in different temperatures were carried out. XRD, SEM and VSM analyses were utilized in order to recognize the phase, morphology and magnetic properties of nanoparticles, respectively. Results showed that nanopowder was prevented from agglomeration using the surfactants. XRD analysis after calcination showed that the formation temperature of barium hexaferrite was decreased in the presence of surfactant. SEM image showed that the surfactant affects the morphology with decreasing the particle size, following by a significant increase in coercivity. Consequently, the optimum results was obtained for the specimen with a molar ratio of Fe / Ba =10 in presence of CTAB surfactant, which calcined at 800°C and resulted in hexagonal plate-like particles of single phase barium hexaferrite with diameters of 70 nm and an average thickness of 30 mm. These particles showed a coercivity and a saturation magnetization of 5156 Oe and 55 emu/grespectively.

کلیدواژه ها:

nano-powder ، magnetic material ، barium hexaferrite ، coprecipitation ، surfactant