Self-ignited synthesis of Mg-Gd-Mn nanoferrites and impact of cation distribution on the dielectric properties

Mg0.9Mn0.1GdxFe2−xO4 nanoferrites were processed for the first time by a solution combustion technique. X-ray diffraction studies revealed the spinel cubic structure of the synthesized ferrites. The particle size was observed to increase (13-16 nm) with an increase in Gd3+ ion content. The cation distribution is inferred from the X-ray diffraction. It is observed from cation distribution that Gd3+ ions preferred octahedral (B) sites. The DC resistivity was found to be increasing with an increase in Gd3+ content. The dielectric constant ε′ and loss tangent (tan δ) was observed to decrease with the addition of Gd3+ content as well as with the increase in frequency. The variations in DC resistivity as well as dielectric constant with the increasing substitution of Gd3+ ions have been correlated to the cation distribution. The very high values of DC resistivity (~108 Ω cm) and low values of loss tangent (0.9-0.008) are the prime achievements of this work.