Glass transition and crystallization of glasses based on rare-earth borates

The glass formation is investigated and the highest contents of rare-earth oxides are determined in glasses of the Ln(2)O(3)-B2O3 system in the composition region (Ln(2)O(3))(1+x) .3B(2)O(3) (Ln = La, Nd, Gd, Er, Dy, Yb, Lu; 0 less than or equal to x less than or equal to 0.8). It is shown that the total content of rare-earth oxides in the La2O3-Ln(2)O(3)-B2O3 ternary system can substantially exceed their highest content in the binary systems. The devitrification of glasses in the La2O3-Ln(2)O(3)-B2O3 system at temperatures above the glass transition point T-g is analyzed.