Popis: |
A series of 0.45BaO–0.05Al2O3–0.5P2O5 glasses doped with V2O5 were prepared. The glass sample containing 1.0% V2O5 exhibited bandpass filters in the photon wavelength ranges of 236–324 nm, 412–482 nm and 682–1500 nm. The phosphate structural units are Q2 linked to AlO6, BaO6, and O3V=O structural units. The optical band gap, Eg, values decreased from 2.253 eV (the base) to 1.968 eV (2.5% V2O5), whereas the refractive index was calculated from the Eg values, which increased from 2.596 (the base) to 2.703 (2.5% V2O5). The glass density, ρ, decreased as the V2O5 content increased from 2.744 g/cm3 to 2.307 g/cm3, and the molar volume, Vm, was calculated from the ρ. The molar refraction, Rm, and polarizability, αm, were calculated from the refractive index and Vm. The optical basicity, Λ, of the glass was discussed in terms of its thermodynamic stability. |