Glass formation area of the CdO-CuCl2-V2O5 ternary system: optical properties as a function of CuCl2 content

Abstract

Within the compositions triangle of the ternary system CdO-CuCl2-V2O5 a batch of 25 glasses were fabricated. In the corner of high CdO content the glass formation area (GFA), was found. For each group, the glass former (V2O5) content was constant and, the modifier oxides CdO, CuCl2were varied. All the fabricated glasses were analyzed by X-ray diffraction patterns, UV-Vis and Raman spectroscopies. In the border of the GFA all the samples presented the crystalline structure of the compound Cd2V2O7, meanwhile inside of the GFA, the samples contain amorphous Cd2V2O7. Into the GFA the samples were organized in 5 groups. For each group, taking as reference the CuCl2 content, the optical properties were analyzed. Under this point of view, the maximum of their Raman band associated with their amorphous structure, is being confined between 850 and 820 cm−1, depending on the CuCl2 content. By optical absorption the Eg values were determined in the 2.42 — 1.66 eV range, depending on the CuCl2 content. By the same spectroscopy the Urbach energy (Eu) for all the glasses was obtained and resulting to be in the 0.65 - 0.22 eV range. The refractive index for this group of samples, was obtained in the 2.57 – 2.90 range, also depending on the CuCl2 content. Finally, SEM images show a homogeneous distribution goticular into the amorphous matrix, for samples located in the border of the GFA.