Improved magneto-dielectric properties in Co substituted Cr ferrites for miniaturized antenna applications

The composition Cr(Fe1-xCox)(2)O-4 with x = 0.0, 0.1, 0.5, and 0.9 has been synthesized using the solid-state reaction method followed by the double sintering technique of pre-sintering at 800 degrees C and sintering at 1332 degrees C. The structure and cationic distribution in the studied samples obtained by the Rietveld refinement of X-ray diffraction (XRD) patterns confirm a mixed spinel cubic structure of Fd3m space group, with a reduction in impurity phase (alpha-Fe2O3) as Co2 + substitution increases. In addition, the scanning electron microscopy (SEM) of these samples indicates a decrease in grain size and porosities with higher Co content. The magnetic hysteresis measurement by a vibrating sample magnetometer (VSM) reveals that Co2+ substitution at Fe3+ enhances the magnetic properties, with maximum saturation magnetization Ms of similar to 4.03x10(-2 )mu B/F.U and coercivity Hc of similar to 102.1 Oe observed for x = 0.5. In addition, the frequency-dependent permeability mu improves with Co doping in Cr ferrite, and dielectric studies exhibit reduced loss tangent (tan delta) and enhanced dielectric quality factor (Q epsilon). Finally, the matching impedance becomes stable across a broad frequency range (3 kHz to 7 MHz) with Z/eta(0)approximate to 0.75, resulting in the Co-substituted Cr ferrites as promising materials for miniaturized antenna applications including superior magneto-dielectric performance and eco-friendly composition.