Investigations of structural modifications, physical and optical properties of lead boro-tellurite glasses doped with europium trioxide for possible optical switching applications

This manuscript intends to the structural modifications, and physical and optical properties of a set of heavy metal alkali boro-tellurite glasses doped with Eu2O3. These glasses were produced by a conservative melt-quenching method. The existence of non-crystalline properties in the glasses was ascertained by X-ray diffraction analysis. The structural modifications were noticed by MAS-NMR spectroscopic investigation. Physical properties such as density, molar volume, oxygen packing density, average boron-boron separation, interionic distance, and polaron radius have been calculated by a suitable approach. The optical absorption studies were made through UV-visible absorption spectroscopy in the 350 nm to 800 nm wavelength range. The optical properties namely, optical energy bandgap, Urbach energy, optical basicity, electronegativity, and electric susceptibility, were also determined by using appropriate methods. The MAS-NMR spectroscopic experiments reveal that fewer BO4 units are converted to BO3 units and those NBOs are turned into bridging oxygen at a lower rate. The optical refractive index values and optical dielectric constant range from 2.241 to 2.358, and 5.0220 to 5.5601, respectively. The obtained energy band gap values (Eg(d): 3.367 eV to 3.597 eV and Eg(ind) 2.109 eV to 2.863 eV) and other significant optical parameters suggest that the investigated glasses are potential candidates for europium-doped fiber amplifier applications and possible optical switching applications.