Mössbauer spectroscopic analysis and temperature dependent electrical study of Mg_0.9Mn_0.1Gd_yFe_2−yO₄ nanoferrites

Mg–Gd–Mn nanoferrites with formulae Mg_0.9Mn_0.1Gd_yFe_2−yO₄, where y=0.05, 0.1, 0.2 and 0.3, have been synthesized by solution combustion technique. The dc resistivity was observed to decrease with the increase in temperature. Dielectric constant (ε′) and loss tangent (tan δ) have been found to be increasing with an increase in temperature while with an increase in frequency both have been found to be decreasing. The ac electrical conductivity (σ_ac) has been studied as a function of temperature at different frequencies and has been observed to be increasing with the increase in temperature. The Mössbauer spectroscopy has been carried out so as to authenticate our previously reported results on the super-exchange interactions. - Graphical abstract: SEM image for Mg_0.9Mn_0.1Gd_0.3Fe_1.7O₄ nanoferrite. - Highlights: • Mg–Gd–Mn nanoferrites are synthesized by solution combustion technique. • High value of dc resistivity (10⁸ Ω-cm) is obtained. • Very low values of dielectric loss tangent at high frequencies were obtained. • Gd³⁺ substitution resulted in weakening of A–B exchange interactions