Synthesis and characterization of Cr substituted Mn–Zn nanoferrites with improved dielectric, electrical conductivity and impedance properties for electronic device applications

In the present study, the impact of Cr ion substitution on Mn–Zn soft nanoferrites has enhanced the dielectric, electrical conductivity, and impedance properties. The nanoferrites have been synthesized via a non-conventional wet chemical-based co-precipitation technique. Raman scattering confirms the spinel nature and also reveals a positive frequency shift with the Cr ion substitution. As Cr ion concentration increases, the dielectric constant (ε′) increases significantly at room temperature. At 100 Hz, x = 0.5 [Mn0.5Cr0.5Fe2O4] resulted in higher value of ε′ ~ 104 and a lower value of loss (tan δ) ~ 3.9. Frequency modulated ac conductivity rises with increasing Cr substitution in Mn–Zn nanoferrites. Electric modulus, impedance spectra, and conduction nature were found to improve with increasing Cr ions. The Nyquist plot shows two semicircle responses in the high and mid-frequency regions, which is due to a conduction mechanism of charges (Fe2+ ↔ Fe3+) that is related to bulk grains and grain boundary contribution, respectively. High dielectric constants and minimum electric loss in soft nanoferrite materials are useful for electronic device applications.