Structural, Optical and Magnetic Characterization of Vanadium Pentoxide Nanoparticles Synthesized in a Gelatin Medium

The V2O5 nanoparticles were synthesized from VCl3 precursor via a rather facile sol-gel route in gelatin medium followed by calcination at different temperatures of 400, 500 and 600 °C. The prepared samples were studied for their structural, morphological, optical and magnetic properties. The results showed that the synthesized particles consist mainly of crystalline α-V2O5 orthorombic phase. The calcination at higher temperatures caused an increment in the amount of other vanadium oxides minor phases, namely β-V2O5, and also increased the crystallite size from about 22 to 29 nm. The lattice contraction observed on calcination at higher temperatures may be associated to the the lower density of oxygen vacancies. The optical studies revealed the effect of raising the calcination temperature as an red shift in their direct band gap energy from 2.92 to 2.77 eV due to the size effects. The magnetic characterization of the sample calcined at 400 °C demonstrated a weak ferromagnetic behavior with saturation magnetization of about 0.14 emu/g induced probably by the oxygen vacancies