RE-crystallization of Nb₂O₅ nanocrystals: a study employing different laser wavelength

The effect of laser wavelength was fully studied and examined for Nb₂O₅ nanoparticles prepared by laser ablation of niobium plate in pure water. 1064 and 532 nm wavelengths were used. Using x-ray diffraction two different crystal structures were identified, Orthorhombic T-Nb₂O₅ and Monoclinic H-Nb₂O₅ for the two wavelengths respectively. A high concentration of spherical, well-defined, and tiny nanoparticles was recognized using a 532 nm laser compared to 1064 nm wavelength employing SEM and TEM images. Strong Raman peaks located at 301.7 cm-1 for orthorhombic T-Nb₂O₅ and at 922.01 confirming the formation of mono-clinic H-Nb₂O₅ for two wavelengths respectively, these results were confirmed by FTIR results which present peaks at 675.5 and 705.9 cm-1related to the same phases. The Eds results show highly stoichiometric crystal reached about 95% using 532 nm laser wave length.