Preparation and properties of highly refractive SmO3/2-TiO2-HfO2 glasses by aerodynamic levitation

The SmO3/2-TiO2-HfO2 (STH) glasses system was successfully prepared using the aerodynamic levitation technique. XRD analysis confirms that the obtained samples are amorphous. Raman spectra demonstrate that the maximum phonon energy is 1060 cm−1. DSC measurements reveal that the addition of HfO2, with its high melting point, increases both Tx and Tg. The maximum ΔT reaches 75.7 °C, and the density of the glass increases from 5.0548 to 5.1097 g/cm3. When the HfO2 content is kept constant, a decrease in Sm2O3 content and an increase in TiO2 content lead to a decrease in Tg and Tx, with a corresponding increase in density. The glass exhibits a maximum Vickers hardness of 8.102 GPa, which can be attributed to the high dissociation energy of Sm2O3, TiO2, and HfO2. Furthermore, both ST and STH glasses show excellent resistance to acid and alkali corrosion. Additionally, the refractive index contribution of each oxide follows the order: TiO2 > HfO2 > Sm2O3. The refractive index increases with increasing TiO2 and HfO2 content. Therefore, it is necessary to adjust the ratio of each oxide to optimize the values of Vm, OPD, and αO2− for a positive effect on the refractive index. The transmittance of STH glass is approximately 70 %, and the internal transmittance is 90 %. This indicates good transmittance even without considering reflection. The glass has a maximum refractive index of 2.343 and an Abbe number υd in the range of 17.06–18.02, meeting the dispersion requirements of commercial optical glasses. These results suggest that STH glass is a highly refractive optical glass with promising potential for various applications.