Structural, optical, magnetic and dielectric properties of Ag doped Mg nano ferrites prepared by citrate gel auto combustion method

•Silver substituted magnesium nano ferrites have been prepared by the Citrate gel auto combustion method.•Fluorescence spectra red shift observed in band edge emission with substitution of Ag+ content.•The impact of Ag+ dopant on various properties has been studied in detail.•As applied frequency increased, dielectric constant and loss decreased, while AC conductivity increased. The Silver Substituted Magnesium ferrites with the formula MgAgXFe2-XO4 (where 0 ≤ x ≤ 0.5 by step 0.1) have been prepared through the citrate gel auto combustion method. Prepared samples structural, morphological, electrical, and magnetic properties have been investigated by XRD analysis, FESEM, AC conductivity, and VSM respectively. XRD and FESEM were used to investigate the structural properties of prepared ferrite materials such as average crystalline size, lattice parameter, X-ray density, unit cell volume, and morphology. Crystalline size was measured to be between 25–30 nm. Five Raman active modes (A1g+Eg+3Tg) were observed in the Raman Spectrum, which are expected in the spinal ferrite system. The prepared sample's structure is confirmed by FTIR spectra bands appearing ∼400 and ∼600 cm−1 wave number region indicates that stretching frequency of tetrahedral (A-site) and octahedral (B-site) respectively. The optical band gap energy of the material observed ranged from 3.44 to 3.51 eV. The variation of dielectric properties has been studied with regard to temperature variation as a function of frequency. All the samples dielectric constant decreases with increasing frequency and temperature, which is the nature of ferrites. It obeys the Maxwell-Wagner type of dispersion because of interfacial polarization. The magnetic properties investigated by room temperature VSM, low coercivity values observed indicate that the sample is of soft magnetic nature. [Display omitted]