Structural and thermal properties of Yb:CaBTeX glasses as a function of TeO2 content

Abstract

Yb3+-doped Calcium Borotelurite glasses were synthesized. The structural and thermal properties were investigated by X-ray diffraction, density, Fourier-transform infrared, Raman, Vickers microhardness, differential thermal analysis, specific heat, and thermal expansion. The thermal mirror was used to determine thermal diffusivity and thermal conductivity. The results were discussed as a function of tellurium oxide content. There were an increase in density and a decrease in Vickers microhardness due to the substitution of CaO, and B2O3 for TeO2. By Fourier-transform infrared spectra, the fraction of tetrahedral borons increase up to 31% mol of TeO2, however, for 54% there was a decrease, indicating a reduction of BO4 and the formation of BO3 units. The thermal expansion coefficient and thermal stability increased with TeO2 content, while there was a reduction for specific heat and thermal diffusivity. The results indicated that Yb:CaBTeX glasses have good thermal and structural properties with potential for applications in optical devices.