Optical properties and glass-forming region of the K2O-Sm2O3-TeO2 glass system

The optical properties and the glass-forming region of the K2O-Sm2O3-TeO2 glass system are studied. In the K2O-Sm2O3-TeO2 system, only the 5K2O-5Sm2O3-90TeO2 composition gives a transparent glass. The refractive index, n, and the optical band-gap energy, Eg, of the 5K2O-5Sm2O3-90TeO2 glass are n = 2.04 ± 0.003 and Eg = 3.2 eV, respectively. A single Sm2Te6O15 phase is found to be formed by a two-step thermal treatment process at 370 °C for 5 h and 390 °C for 5 h. This is the first report on the crystallization and the preparation of the K2O-Sm2O3-TeO2 glass system.