EFFECT OF Nd-DOPING ON THE NANOCRYSTALLITE SIZE AND MICROWAVE ABSORPTION PROPERTIES OF Sr-HEXAFERRITE

Nd-doped M-type Strontium hexaferrite powders with composition of Sr1-xNdxFe12O19 (x = 0, 0.1, 0.2) were prepared by conventional ceramic method at various calcination temperatures. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used for characterization of the obtained powders. The results showed that by increasing Nd doping, the single phase magnetoplumbite structure has been formed at higher temperatures. The average crystallite size of the samples calculated by the Scherrer formula indicates that Nd-doping resulted in a significant decrease in the mean crystallite size. The hexaferrite-polymer bulk composites in epoxy resin matrix, with ferrite ratio of 90 wt.%, were also prepared. The microwave absorption properties of these composites were investigated in 8-12 GHz frequency range by means of a vector network analyzer. Due to the reflection loss measurements, Nd-doped Sr-hexaferrite could be a promising material for microwave absorption applications in X-band.