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 (Cu_xZn_1-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 Cu_xZn_1-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 Cu_xZn_1-xFe₂O₄ for potential applications in catalytic and magnetic applications