Investigation on various properties of hexaferrites and composites to find potential applications

Abstract

newlineA series of Erbium substituted X-type Ba2Co2ErxFe28-xO46 (x = 0.00, 0.04, newline0.08, 0.12, 0.16, and 0.20) hexaferrites were prepared by the method of heat newlinetreatment. The obtained precursors were heated at 1350 °C for 6 h. XRD newlineinvestigation reveals that x = 0.0 sample possesses X, W-type, and and#945;-Fe2O3 newlinephases, while Er- substituted samples show presence of X and W phases. newlineThe room temperature Mössabuer spectra have been fitted with five sextets. newlineA variation in saturation magnetization (MS) is explained and supported by newlinethe Mössbauer spectroscopy. The maximum values of MS (52.29 Am2/kg) newlineand anisotropy field- Ha (1370 kA/m) are found for x = 0.12 composition. newlineSimilarly, the maximum relative area (and#8764; 69%) for spin up sites (k+a+b) is newlinealso found for x =0.12 composition. Low frequency (20 Hz 2 MHz) dielectric newlineresponse of all samples show normal behavior of ferromagnetic materials. newlineThe dielectric measurements reveal that the conduction in low frequency is newlinedue to grain boundary contributions and at the higher frequency it is due to newlinegrain contributions. AC conductivity is found to increase with frequency in newlineall prepared hexaferrites. The substituted compositions can have potential newlineapplications in filter application due to soft ferrite behavior and low dielectric newlineloss tangent. newlineSrFe12O19 (M-type hexaferrite) and NiFe2O4 (spinel) nano ferrite powders newlinewere synthesized in the presence of Calotropis gigantea (crown) flowers newlineextract separately. SrFe12O19/NiFe2O4 nanocomposites were prepared in the newlinepresence of crown flowers extract and the effect of different weight ratios newline(M:S 9:1, 8:2, 7:3, 6:4, 5:5) on structural, microstructural, magnetic, electrixi newlinexii newlinecal transport, and dielectric properties were studied. The average crystallite newlinesize of nanocomposites was found from 25 nm to 44 nm. In addition, it was newlineobserved that the crystallite size of the M-phase decreased when the spinel newlinephase increased. XRD analysis depicts the presence of both M and S phases newlinein composites. The M-H loops analysis of SrFe12O19/NiFe2O4 composi