The effect of Co and Zr substitution on dc magnetic properties of Ba–Sr ferrite

M-type hexagonal ferrite series, Ba0.5Sr0.5Cox ZrxFe(12−2x)O19 (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0), has been synthesized by conventional ceramic method. Magnetic properties have been investigated as a function of substitution of Co and Zr ions at applied field of 10 kOe. XRD and SEM confirmed hexagonal structure of ferrite. The substitution causes reduction in anisotropic field and change in microstructure. The magnetic parameters have been characterized by taking into account microstructure and preferential site occupancy of sublattice sites by substituted ions. Curie temperature decreases with substitution due to weakening of superexchange interaction. The change in magnetic parameters results in possible use of substituted ferrite for recording media.