Optical and Multiferroic Properties of Gd-Co Substituted Barium Hexaferrite

This report demonstrates Gd-Co substituted M-type barium hexaferrite, Ba1-xGdxCoxFe12-xO19, 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 Fe3+ 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.