Enhancement in physical properties of barium hexaferrite with substitution

M-type barium hexaferrite powders were synthesized using modified Pechini sol gel auto combustion method. The powder samples were heat treated at 900 degrees C for 5 h and were subjected to the structural, thermal, dielectric, magnetic, and optical studies. X-ray powder diffraction patterns show the formation of pure phase of M-type hexaferrite. Thermal analysis reveals that the weight loss of precursor becomes constant after 680 degrees C. The presence of two prominent peaks near 430 and 580 cm(-1) in Fourier transform infrared spectroscopy spectra indicates the formation of M-type hexaferrites. The M-H curve has been used to study the magnetic behavior. The maximum value of coercivity is found for x = 0.41, which is higher than that of the pure barium hexaferrite. The band gap dependency on composition was studied using UV-Vis NIR spectroscopy. It was found that the dielectric constant is high at low frequency and decreases with an increase in frequency. Hexagonal structure of hexaferrite is visualized in transmission electron images.