Glass formation in the MoO3–Nd2O3–La2O3–B2O3 system

In MoO3–Nd2O3–B2O3 and MoO3–Nd2O3–La2O3–B2O3 systems, glasses were obtained in the region between 20 and 30 mol% Ln2O3. A liquid-phase separation region was observed near the MoO3–B2O3 side up to 20 mol% Ln2O3 (La, Nd). The amorphous phases were characterized by X-ray diffraction (XRD), differential thermal analysis (DTA), UV–VIS and infrared spectroscopy (IR). According to DTA data B2O3-rich glasses are stable up to 630 °C while glasses rich in MoO3 are stable up to 430 °C. The glasses are transparent in the visible region. Structural models for the glasses network were suggested on the basis of IR spectral investigations. It was established that BO3 (1380 cm−1), BO4 (1100–950 cm−1) and MoO4 (860 cm−1) groups build up the glass network. MoO6 units (band at 880 cm−1) together with BO3 units participate in the formation of the glass network with a high MoO3 content (80–90 mol%).