Synthesis and Optical, Thermal, Structural Investigation of Zinc-Borate Glasses Containing V2O5

Abstract

Vanadium pentaoxide (V 2 O 5 ) doped zinc borate (ZnB) oxide glasses that could be used in fiber optic cable cores in optoelectronics, in laser crystals in solar energy systems have been synthesized successfully. Structural characters of synthesized glasses were determined with differential scanning calorimeter (DSC) and Fourier-Transform infrared spectroscopy (FTIR). Glass transition (T g ), crystallization (T c ) and melting temperatures (T m ), and thermal stabilities ($\Delta$T) of the glasses were determined and also their association with the change in V 2 O 5 was explained. Structural units of boron and zinc that form the structure were determined according to FTIR data. As a result, it was determined that boron formed the glass matrix with BO 3 , BO 4 and boroxol ring structural units; on the other hand, zinc contributed to the glass matrix with tetrahedral ZnO 4 and octahedral ZnO 6 structural units, and vanadium usually had modifier role in the structure with its VO 4 and VO 5 structural units. V 2 O 5 ’s presence in the structure with increasing amount changes thermal, structural and physical properties. Among the properties that significantly change, the most important one is optical properties. Indirect optical band gaps, Urbach energies, refractive index values of these synthesized samples were determined, and quite clear shifts towards red region were observed in the transmittance and absorption spectra. Optical band gap decreased to 1.24 eV from 2.55 eV with increasing amount of V 2 O 5 ; on the other hand, Urbach energy was determined to increase to 0.630 eV from 0.246 eV. Densities, molar volumes of these synthesized glasses were also examined and commented on.