Tailoring the structural and dielectric properties of ZnFe2O4 through annealing temperature

In this study, we synthesized nano-crystalline ZnFe2O4 through the sol-gel method and explored the impact of annealing temperature on its physical properties. The average crystallite size, determined using the Debye-Scherres's formula with data obtained from Rietveld-refined X-ray diffraction, increased from 16 nm to 58 nm as the annealing temperature rose from 200 to 1000 K. FTIR spectra showcased vibrational modes corresponding to metal-oxygen bonds at both octahedral and tetrahedral sites. UV–Vis DRS measurements uncovered a widening of the optical band gap from 2.03 eV to 2.14 eV with increasing annealing temperatures. The rearrangement of cations exerted a substantial influence on the dielectric properties and AC conductivity. Dielectric assessments illustrated a diminishing trend in both the real and imaginary components of impedance as frequency progressed, decreasing from 107 at 100 Hz to 10 at 100 MHz. Additionally, conductivity investigations emphasized that the AC conductivity of ZnFe2O4 experiences enhancement at higher frequencies.