Coprecipitation Prepared By M-type Barium Ferrite And Performance Studies

High purity and small particle sized Ba-M-type hexagonal ferrites (BaFe12O19) have been prepared by co-precipitation method. Different factors of co-precipitation have been explored in this paper, such as precipitant, the way of precipitant dropping, pH of coprecipitating solution, calcination temperature and time of co-precipitation precursor, etc. The effects of different dispersing agents have been studied as well. Investigation of different doping amount of La3+and Ce4+/Co2+have been carried out, in order to find out the influence on phase, structure and magnetic properties.The XRD results showed that the combination of Na2CO3 and NaOH as precipitant and dropped reversely get less impurity phase product. When calcination temperature raised to 850℃for 1h or more, there is only pure product left.IR and BET analysis showed that porous structure formed in co-precipitation precursor after the introduction of dispersing agents, and there are few dispersing agents residue in the precursor after repeated washing with water and ethanol. After calcining at 850℃for 2h, IR results showed that no dispersing agent existed in the precursor, but porous structure in the product collapsed seriously and specific surface area decreased obviously. The density of products significantly declined respectively with increasing amount of PEG-800.The doping amount of La3+ in the range(x=0.0-0.5) has no influence on purity of product, but product of Ce4+/Co2+ doped at certain amount (x=0.3～0.5) CeO2 appeared. SEM images showed that the doping of ions have no affect to the morphology of products.Magnetic characterization indicated that ions doping have great influence on Ba-M-type hexagonal ferrites. Saturation and remanent magnetization decreased respectively with increasing amount of doping ions. Ce4+/Co2+ doping have greater impact on coercivity of product. Coercivity of product decreased obviously with increasing amount of doping Ce4+/Co2+. Coercivity of La3+ doping product did not change obviously. Therefore, it is possible to dope different ions with proper amount into Ba-M-type hexagonal ferrites in order to prepare required products.