Preparations And Magnetic Properties Of M-type Barium Hexaferrites Through Doping Co/Sm Ions

M-type barium hexaferrites is magnetic functional material with widepotential. The investigation has focused on the new synthesis methods andmodification on the characters in order to obtain good performance M-typebarium hexaferrites. In this paper, M-type barium hexaferrites particles weresynthesized via chemical co-precipitation method, in which the method wasestablished to prepare the series doped sample. These materials werecharacterized by XRD、SEM、VSM, and then studied in detail.Different factors of chemical co-precipitation have been explored in thispaper， such as precipitant, pH of coprecipitating solution, calcinationstemperature and time of co-precipitation precursor, etc. The XRD results showedthat the combination of Na₂CO₃and NaOH as precipitant and dropped reverselyget less impurity phase product. When calcinations temperature raised to900℃for l h or more, there is only pure product left.Co²⁺and Co²⁺，Sm³⁺doping M-type barium hexaferrites series sampleswere prepared by chemical co-precipitation method. With increasing ofsubstitution content x, particle sizes decreased, and the coercivity （Hc） decreaseswith increase in cobalt content x. The saturation magnetization （Ms） firstincreases reaching a maximum of63.684emu/g at x=0.4, and then decreases. Thecoercivity （Hc） decreases with increase in Co²⁺and Sm3+content. The saturationmagnetization （Ms） increases reaching a maximum of54.44emu/g at x=0.1.Therefore，it is possible to dope different ions with proper amount into M-typebarium hexaferrites in order to prepare required products.