Simultaneous effect of crystal lattice and non magnetic substitution on magnetic properties of barium hexaferrite.

The aluminium doped barium hexaferrite BaFe_12-xAl_xO₁₉ with x =0.0, 1.0, 2.0, 4.0 and 6.0 have been synthesized by the sol-gel method to modify the magnetic properties for technological applications. The crystal structure and phase purity of all the samples have been explored by employing the X-ray diffraction (XRD) technique. It confirms that the sample is nanocrystalline, hexagonal symmetry and all the intense peaks could be indexed to the <italic>P6</italic>_{<italic>3</italic>}<italic>/mmc</italic> space group. The obtained lattice parameters from the XRD analysis decrease with the increase in Al³⁺ content in the samples. The microstructural morphology and particle sizes of all samples were studied by using the Field Emission Scanning Electron Microscopy (FESEM-Hitachi-S4800) technique. The magnetic hysteresis (M-H) loops measurement has been carried out at room temperature by employing the vibrating sample magnetometer (VSM) over a field range of +20 kOe to -20 kOe. The magnetic hysteresis (M-H) loops revealed the ferromagnetic (hard magnetic materials) nature of the samples and, analyzed by using the Law of Approach to Saturation. [ABSTRACT FROM AUTHOR]