Structural and magnetic aspects of aluminium substituted dual lanthanum and calcium based hexaferrite nanoparticles for magnetic applications

In the current work, M-type aluminium substituted calcium-lanthanum hexaferrite with chemical formula Ca_0.5La_0.5Fe_12-xAl_xO₁₉ (x = 0.00, 0.04, 0.08, 0.12, 0.16) is synthesized by the sol–gel auto combustion method. M-type hexaferrite's sole-phase crystalline structure was confirmed by X-ray diffraction analysis, which was further used to compute different structural parameters. Structural refinements showed that cell volume decreases from 696.86 ų to 692.01 ų. Moreover, different microstructural parameters are computed, including X-ray density, bulk density, porosity, microstrains and dislocation density. According to VSM analysis, saturation magnetization-(Ms) and remanence magnetization-(Mr) decreased to 17.01 emug⁻¹ and 10.66 emug⁻¹, respectively, while the coercivity increased to 2.165 kOe by increasing the doping concentration to a maximum of x = 0.16. Other magnetic parameters like anisotropy field-(Ha), anisotropy parameter-(B), and magnetocrystalline anisotropy constant-(K), the magnetic moment per formula unit-(µ_B) were also determined. According to these findings, the synthesized material has excellent potential to be used in magnetic applications.