Investigation of Optical and Structural Properties of CuxZn1-xFe2O4 Spinel Thin Films

This study presents the synthesis and structural characterization of copper-substituted zinc ferrite (CuxZn1-xFe2O4, x= 0 – 0.09) thin films deposited by electric field enhanced spray pyrolysis—a novel technique for this material system. X-ray diffraction (XRD) investigation demonstrated a cubic spinel structure (space group: Fd-3m) with a preferred (311) orientation in all the compositions. The crystallite size, as estimated from the Williamson-Hall method, varied between 20.92 nm (x = 0) and 66.13 nm (x = 0.09), while the lattice constant decreased from 8.44 Å (x = 0) to 8.30 Å (x = 0.09), indicating compressive strain upon Cu substitution. The cubic spinel phase was also verified using Raman spectroscopy, as it showed the characteristic modes (T2g, Eg, and A1g). The A1g mode shifted from 608.72 cm⁻¹ (pure ZnFe2O4) to 591 cm⁻¹ (x = 0.09), suggesting lattice distortion due to Cu incorporation. In addition, the variation in the Copper ion content affects the band gap of CuxZn1-xFe2O4. The band gap changed between 2.46 eV and 2.92 eV for x= (0 – 0.05). The findings demonstrate that electric field-enhanced spray pyrolysis effectively tunes the structural properties of CuxZn1-xFe2O4 for potential applications in catalytic and magnetic applications