Herein, polyvinyl alcohol (PVA) acts as a host matrix for manganese-nickel ferrite (Mn0.4Ni0.6Fe2O4) nanoparticles (NPs). Oxalate precursors and a solution-cast method were used to produce a Mn0.4Ni0.6Fe2O4 spinel structure and PVA-Mn0.4Ni0.6Fe2O4 films, respectively. X-ray diffraction (XRD), scanning electron microscopy, optical microscopy (OM), a surface roughness tester, and FT-IR spectroscopy were used to identify the structure and morphology of the PVA-Mn0.4Ni0.6Fe2O4 films. XRD confirmed the formation of Mn0.4Ni0.6Fe2O4 spinel, and its additive into the PVA matrix causes an increase in the PVA amorphousity. The PVA-Mn0.4Ni0.6Fe2O4 film's transmission and absorption spectra were recorded with the help of a UV-visible spectrophotometer. The addition of 4%Mn0.4Ni0.6Fe2O4 to PVA resulted in a decrease in the optical bandgap from 5.53 eV to 4.83 eV. The Urbach energy increases from 0.46 eV for pure PVA to 2.14 eV for PVA-4%Mn0.4Ni0.6Fe2O4, indicating a rise in the defect density. In addition, the refractive index and extinction coefficient were calculated theoretically and were found to increase as the Mn0.4Ni0.6Fe2O4 content increases in the PVA matrix.
SEM images and EDX for Mn0.4Ni0.6Fe2O4 and PVA-4% Mn0.4Ni0.6Fe2O4 film