Abstract

W-type hexaferrites with nominal composition Sr_1−xCe_xCo₂Mn_yFe_16−yO₂₇ (x = 0.00, 0.02, 0.04, 0.06 & y = 0.0, 0.2, 0.4, 0.6) has been synthesized by the chemical co-precipitation method. The effect of substitution of Ce at Sr & Mn at Fe site on the structural, magnetic and electrical properties has been investigated. The XRD patterns confirm single W-type hexaferrite phase and various parameters such as lattice constants (a & c), cell volume (V), crystallite size (D), X-ray density (d_x), bulk density (d_b) and porosity (P) were calculated from XRD data. The crystallite size is found in the range of 22.5–30 nm and this size is small enough to obtained suitable signal-to-noise ratio in high density recording media. The magnetic properties such as saturation magnetization, remanence, squareness ratio and coercivity were calculated from hysteresis loops and were observed to increase with increase in Ce–Mn concentration up to a certain substitution level. The resistivity showed interesting behavior with temperature, showing metal-to-semiconductor transition temperature. The increase in saturation and remanence suggest that the synthesized materials can be used in the high density recording media.

Graphical abstract

The saturation magnetization and remanence increase with the Ce–Mn content and the maximum value is found for the sample Sr_0.98Ce_0.02Co₂Mn_0.2Fe_15.8O₂₇ which suggest that this material can be used for high density recording media.