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SummaryA study on radiation losses in conducting polymer nanocomposites, namely La–Co-substituted barium hexaferrite and polyaniline, is presented. The study was performed by means of a vector network analyser, X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, electron spin resonance spectroscopy and a vibrating sample magnetometer. It is found that the maximum loss occurs at 17.9 GHz (−23.10 dB, 99% loss) which is due to the composition of a conducting polymer and a suitable magnetic material. A significant role of polyaniline has been observed in ESR. The influence of the magnetic properties on the radiation losses is explained. Further studies revealed that the prepared material is a nanocomposite. FTIR spectra show the presence of expected chemical structures such as C–H bonds in a ring system at 1512 cm−1.

This report demonstrates Gd-Co substituted M-type barium hexaferrite, Ba 1-x Gd x Co x Fe 12-x O 19 , successful synthesis adopting sol gel method. Formation of crystalline magneto-plumbite structure and presence of other phases are verified from the X-ray diffraction analysis. Vibrational modes in FT-Raman spectra show the formation of P63/mmc group can be related with magneto-plumbite structure. TEM images of these materials are also discussed. UV-Vis-NIR spectra shows that with material substitution optical energy band gap increases 3.99 eV to 4.28 eV. The observed Fe 3+ ions peak could be correlated to peak line width and occurrence of symmetrical resonance in electron spin resonance (ESR) spectra. The dielectric constant shows high value at low frequency and it becomes constant at high frequency. The retentivity and coercivity of the material decreases with increasing substitution. Multiferroic nature of hexaferrite is analyzed using ferroelectric loops.

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