PREPARATION, DIELECTRIC AND OPTICAL PROPERTIES OF Cr2O3 /PVC NANOCOMPOSITE FILMS

Abstract

Chromium oxide (Cr₂O₃) nanoparticles were synthesized using a sol-gel method and mixed with polyvinyl chloride (PVC). Rietveld refinement of X-ray powder diffraction (XRD) patterns of the samples revealed that the crystal structure of Cr₂O₃ is rhombohedral with space symmetry group. Scanning electron microscopy images showed that the Cr₂O₃ nanoparticles are well dispersed on the surface of the PVC films. The dielectric permittivity (e'), and ac conductivity (σ_ac) of pure PVC increased with adding Cr₂O₃ due to the formation of conductive three-dimensional networks throughout the nanocomposite films and interfacial polarizations. The optical energy band gap (E_g) of the films decreases with increasing Cr₂O₃ content. The refractive index dispersion of the nanocomposite films obeys the single oscillator model. The dispersion parameters are changed by incorporation of Cr₂O₃. The optical properties of PVC are influenced by addition of Cr₂O₃ nanoparticles.