Structural and Dielectric Properties of Hexaferrite-spinel Composites Prepared using a Sol-gel Auto Combustion Technique

Hexa-spinel ferrite composites with various mass ratios (1:1, 1:2, 1:5, and 1:8) of the two constituent phases Ba₂Ni₂Fe₁₂O₂₂ and CuFe₂O₄ were prepared by Sol-Gel auto combustion technique. The effects of composition on the crystallography, particle morphology, and Dielectric constant were investigated. The XRD patterns of the composites reveal that all the composites were consisted of two phases: hexagonal and spinel. The absence of new phase proved that there was no chemical reaction between spinel and hexagonal ferrites. The SEM photographs show that the two kinds of phases were distributed homogenously. All the samples show the frequency dependent phenomena, i.e. the dielectric constant decreases with increasing frequency and then reaches a constant value.