Exploring the microstructural and magnetic parameters of Ba0.3Sr0.3Ca0.4Al0.5SmxFe11.50-xO19 (x = 0.00, 0.25, 0.50, 0.75) hexaferrite nanoparticles

Abstract

In this work, Ba_0.3Sr_0.3Ca_0.4Al_0.5Sm_xFe_11.50-xO₁₉ (x = 0.00, 0.25, 0.50, 0.75) hexaferrites were synthesized using the sol–gel auto-combustion approach. The synthesis of M-type hexaferrites without impurities is confirmed by X-ray diffraction analysis. Refined lattice parameters were used to calculate the unit cell volume. The volume increased to the value of 698.78 ų and Porosity reached to maximum value of 14.34 % for maximum doping level x = 0.75. Using scanning electron microscopy, the surface morphology of the synthesized Sm-substituted hexaferrite nanoparticles was investigated. In the pure sample, there are tiny agglomerate particles that do not possess any particular geometric shape. Maximum doping concentration x = 0.75 resulted in variations of Ms to 36.15 emu/g, Mr to 20.55 emu/g, and magnetic coercivity 4.117 kOe. All of the sample’s Mr/Ms values greater than 0.5, indicated that the synthesized hexaferrite nanoparticles have a single-domain magnetic structure. The results show that as dopant concentrations rise, magnetocrystalline anisotropic constant (K), magnetic moment per formula unit (m_B(μ_B)), anisotropy field (Ha), anisotropy parameter (B) values increase proportionately to 0.0292 erg/kOe, 7.211µ_B, 1.286 kOe, 110329.7 respectively. High values of the discussed magnetic parameters make the material suitable for high-density data storage, EMI shielding, spintronic devices, and automotive sensors.