No abstract

A series of stable and transparent glasses with the composition 59B 2 O 3-10Na 2 O-(30 − x) CdO-xZnO-1CuO (0 ≤ x ≤ 30) (where x = 0, 7.5, 15, 22.5, and 30 mol%) were prepared by conventional melt-quenching technique. These glasses were characterized using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) and Raman spectroscopes, differential scanning calorimetry (DSC), optical absorption, and electron paramagnetic resonance (EPR). XRD and DSC analysis confirmed the glassy nature of the prepared samples. The physical properties such as density (ρ), molar volume (V m), oxygen packing density (OPD), and the molar volume of oxygen (V o) were calculated and discussed. FTIR and Raman studies showed that the glass network consists of BO 3 and BO 4 units in various borate groups. From DSC, it was found that the glass transition temperature (T g) varies nonlinearly with the addition of ZnO content in place of CdO. Both EPR and optical absorption results have confirmed that the Cu 2+ ions are in octahedral coordination with a strong tetrahedral distortion. The changes in various spectroscopic properties of Cu 2+ ions in the glasses such as spin-Hamiltonian parameters () and bonding coefficients (α 2 , β 1 2 , and β 2) were understood with the help of FTIR and Raman studies.

Glasses with compositions 59B2O3-10K2O-(30-x)ZnO-xBaO-1CuO were prepared using melt quenching technique. The effect of BaO content in present glass system doped with copper ion in place of ZnO has been studied with respect to structural properties. Raman spectroscopy is an experimental technique appropriate for providing information about  the structure, local arrangement of the atoms in the present glasses. The Raman spectra of glasses were recorded at room temperature in the range 200-1800 cm-1 using a He-Ne excitation source having wavelength 632.81 nm. The Raman peaks appeared around 760 cm-1 assigned symmetric breathing vibrations of six-membered ring with both BO3 triangle and BO4 tetrahedral. The intensity of these peaks is slightly varied with the addition of BaO content while the broadness is found to be larger at 30 mol% of BaO than 30 mol% ZnO. This indicates that certain BO4 units could be preferentially converted while those in ring groups could be stabilized. Raman studies it is concluded that present glasses are composed of [BO4] and [BO3] units in metaborate, orthoborate, diborate groups.