Abstract
BaBi(x)La(x)Y(x)Ee(12-3x)O(19) (0.0 <= x <= 0.33) hexaferrites were synthesized by sol-gel autocombustion method and the effects of Bi, La, Y substitutions on structural, magneto-optical properties of barium hexaferrite were investigated. X-ray diffraction (XRD), Scanning electron microscopy (SEM), Vibrating sample magnetometer (VSM), and Percent diffuse reflectance spectroscopy (DR %), were used to study the physical properties. XRD peaks showed pure single phase of hexagonal ferrites and the average crystallite size varies in a range of 42.35-49.90 nm. Room temperature (RT) specific magnetization (sigma-H) data revealed the strong ferromagnetic nature of hexaferrite with remanant specific magnetization (sigma(r)) in the range of 29.9-34.6 Am-2/kg and extrapolated specific saturation magnetization (sigma(s)) in the range 53.69-67.42 Am-2/kg. The maximum coercive field (H-c) of 3.812 x 10(5) A/m (belongs to BaFe12O19) decreases to minimum 2.177 x 10(5) A/m with increasing ion substitution. Magnetic anisotropy was confirmed as uniaxial and effective anisotropy constant (K-eff) takes values between 2.532 x 10(5) J/m(3) and 3.105 x 10(5) J/m(3). The anisotropy field (H-a) around 1.6 T revealed that all samples are magnetically hard materials. The Tauc graphs were plotted to estimate the direct optical energy band gap (E-g) of hexaferrite. The E-g values decreased from 1.88 eV to 1.69 eV with increasing Bi, La, Y compositions. (C) 2016 Elsevier B.V. All rights reserved.