Microstructure and magnetic properties of Y substituted M-type hexaferrite BaYxFe12-xO19

Y (yttrium)-substituted M-type hexaferrite of composition BaYxFe12-xO19 (x ranges from 0.1 to 0.8 with step of 0.1) was synthesized through ceramic process. Pure phase formation of M-type hexaferrite was confirmed by XRD patterns for prepared sample when x<0.4. The second phase (Y3Fe5O12) was detected when the substitution content exceeded 0.4. As the substitution dosage of yttrium increased, unconspicuous transform were observed in the microstructure of all samples BaFe12-xYxO19, such as compactness, size of grain. The bulk densities () of the samples decreased first and then increased with the increase of X. It means that the compactness of the sample receded first and then enhanced with rise of Y3+ substitution contents. Moreover, with increase of Y3+ amount, Y3+ substituted the Fe3+ in the octahedral position of m-type barium ferrite, the saturation magnetization (M-s) of the sample decreases rapidly and obtained a minimum of 55.63 emu/g, and then increased gradually attributed to the appearance of the second phase (Y3Fe5O12). Appropriate values of M-s (56.57 emu/g) and H-c (1794.17 O-e) were obtained simultaneously when x=0.6. These two characters made the material suitable for the applications infield of magnetic recording.