Al-substituted Mg nanoferrite structural, optical and electromagnetic behaviour prepared via citrate gel auto-combustion method

From the citrate gel auto-combustion method, spinal ferrite of Al-substituted Mg nanoferrites has been synthesized. Structural, optical, and electromagnetic behaviours were reported by XRD, UV–Vis, dielectric studies, and VSM, respectively. According to XRD analysis, the phase of the nanoferrites belongs to the FD3M space group and has a crystalline size of 14–25 nm. The lattice constant is found to be 7.841–8.296 Ao. The FTIR spectral bands appearing in the 600 & 400 cm−1 wavenumber regions indicate that the prepared sample has a tetrahedral (A site) and octahedral (B site) structure, respectively. In the Raman spectra, five active modes (A1g + Eg + 3Tg) were observed, which would be expected in the spinel ferrite system. The optical band gap energy was obtained from the UV–visible spectrum and found to be 3.43 to 3.49 eV. The effects of aluminium substitution on AC conductivity, impedance analysis, dielectric constant, and loss were investigated. The AC conductivity increased with applied frequency and temperature, whereas the dielectric constant and loss decreased, which phenomenon was explained by the Maxwell–Wagner polarization theory. Single semi-circle behaviour is observed in the impedance spectrum.