Dielectric and electrical enhancement of niobium pentoxide and vanadium pentoxide scattered in Poly-vinyl alcohol for electrical applications

Abstract

The investigation focuses on polymeric nanocomposites based on PVA doped with niobium oxide (Nb₂O₅) and vanadium pentoxide (V₂O₅). The structure of the fabricated nanocomposites was examined via various methods. Morphological analysis revealed that the average particle size of Nb₂O₅ in PVA-Nb₂O₅ is approximately 110 nm, while in PVA-Nb₂O₅-3%V₂O₅, Nb₂O₅ reaches 103 nm, and V₂O₅ particles are dispersed with an average size of 35 nm. Thermal analysis via TGA demonstrated enhanced stability, with the total weight loss decreasing upon filler insertion. The residual mass increased due to the presence of inorganic oxides, with a final residue of 4.9% for pure PVA and increasing with Nb₂O₅ and V₂O₅ doping. Furthermore, optical studies showed an x-axis shifting absorption edge for PVA, which starts at 3.8 eV and lowers to 2.5 eV for PVA-Nb₂O₅-7%V₂O₅ nanocomposite. The indirect band gap decreases for all nanocomposites, reaching 2.85 eV in PVA-Nb₂O₅-7%V₂O₅ nanocomposite, compared to 5.5 eV in PVA. In contrast, the refractive index registers 1.687 in PVA and increases to 2.075 in PVA-Nb₂O₅-7%V₂O₅ nanocomposite. Moreover, dielectric measurements revealed that the dielectric constant rose to 43 in PVA-Nb₂O₅ nanocomposite but fell from approximately 30 for PVA to less than 20 following doping with V₂O₅. The high relative permittivity of Nb2O5 (100) and V₂O₅ (25) suggests their suitability for advanced dielectric applications. AC resistivity measurements showed an increasing trend with frequency, reaching their highest value at PVA-Nb₂O₅-7%V₂O₅. The optical and dielectric analysis of PVA-Nb₂O₅-V₂O₅ nanocomposites obtained unique behavior in line with earlier studies. Thus, the examined nanocomposites present a potentially useful nano-composite for optoelectronic applications.