title: Impact of vanadium ions in barium borate glass.
abstract: Combined optical and infrared spectral measurements of prepared barium borate glasses containing different concentrations of V2O5 were carried out. Vanadium containing glasses exhibit extended UV-visible (UV/Vis.) bands when compared with base binary borate glass. UV/Vis. spectrum shows the presence of an unsymmetrical strong UV broad band centered at 214 nm attributed to the presence of unavoidable trace iron impurities within the raw materials used for the preparation of such glass. The calculated direct and indirect optical band gaps are found to decrease with increasing the vanadium content (2.9:137 for indirect and 3.99:2.01 for direct transition). This change was discussed in terms of structural changes in the glass network. Infrared absorption spectra of the glasses reveal the appearance of both triangular and tetrahedral borate units. Electron spin resonance analyses indicate the presence of unpaired species in sufficient quantity to be identified and to confirm the spectral data.
authors.affiliation: Spectroscopy Department, Physics Division, National Research Center, Dokki, 12311 Cairo, Egypt. Electronic address: a.m_abdelghany@yahoo.com.
authors.forename: A M
authors.initials: AM
authors.lastname: Abdelghany
authors.affiliation: Thin Films and Electron Microscope Department, National Research Center, Dokki, 12311 Cairo, Egypt.
authors.forename: Ahmed H
authors.initials: AH
authors.lastname: Hammad
mesh_terms: D017609:Barium Compounds / Q000737:chemistry*; D001881:Borates / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D005898:Glass / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D014639:Vanadium / Q000737:chemistry*
chemical_list: D017609:Barium Compounds; D001881:Borates; D007477:Ions; C102738:barium glass filler; D014639:Vanadium; D012822:Silicon Dioxide
keywords: Barium borate glass; ESR; FTIR; UV–Vis. spectra; V(2)O(5)