Synergistic Effect of Ge Addition on Optical, Thermal, and Mechanical Properties of Se-Te-Pb Chalcogenide Glasses
摘要
In this study, Ge-doped selenium-based glasses are synthesized using the melt-quenching route. The amorphousness of the glass samples is verified by an x-ray diffraction study. Density measurements, obtained through Archimedes’ technique, reveal an increase from 5.64 to 5.79 g cm−3. UV–Vis absorbance spectra are analyzed within the range of 200–900 nm to determine the spectroscopic properties. As the amount of the dopant increases, the calculated Urbach energy increases from 0.12 eV to 0.41 eV, while the optical energy bandgap decreases from 1.22 eV to 1.10 eV, as determined using the Tauc plot method. Higher Ge content influences various optical parameters, including the absorption coefficient, refractive index, and optical conductivity of the glassy systems. The pulse-echo technique is employed to measure the longitudinal and shear ultrasonic wave velocities at room temperature, facilitating the calculation of experimental elastic moduli. The longitudinal and transverse wave velocities increase from 2180 to 2460 m s−1 and from 1060 to 1315 m s−1, respectively. Various elastic properties such as micro-hardness, Young’s modulus, Poisson’s ratio, shear modulus, and bulk modulus were derived from the estimated ultrasonic velocity values. The measured elastic moduli are further analyzed using theoretical calculations based on the bond compression model. DSC thermograms showed that the glass transition temperature (Tg) and crystallization temperature (Tc) increased from 353 K to 391 K and from 521 K to 562 K, respectively, with the incorporation of Ge atoms.