Influence of Mg2+ Substitution on Structural, Electrical Polarization, Optical Properties and magnetic Properties of Sr-Based R-Type Hexagonal Ferrites

In this research work the substitutional effect of Mg2+ on Structural, Electrical Polarization, FTIR, SEM and magnetic properties of Sr1-xMgx Mn2 Fe4 O11 R-type hexaferrite nanoparticles with compositions (x= 0, 0.25, 0.75,1.0) were investigated. The sol-gel auto-combustion method was adopted to synthesize the samples, and the powder was sintered at 800°C for 4 hours to achieve the stable hexagonal phase. XRD pattern showed that all the prepared samples have a single phase R-type hexagonal structure. The lattice parameter a, c, and unit cell volume V decreased with Mg substitution. The dislocation density increased with Mg substitution, while crystalline size varied with Mg doping. The Fourier transform infrared spectroscopy (FTIR) spectra further verified the single hexagonal phase of the produced samples. The saturation and remanent polarization increased with Mg substitution in the polarization versus electric field loops. The P-E loops also indicate the lossy behavior decreased with Mg substitution. By substituting Mg+2, the saturation magnetization, retentivity, and coercivity increased initially, then decreased. VSM measurements reveal ferrimagnetic and paramagnetic nature for all the samples.