Investigation of phase separation in Nd3+ doped ternary sodium borosilicate glasses by optical spectroscopy

Two glasses doped with 1 mol% Nd2O3 and batch compositions inside the misci bility gap of the ternary Na2O-B2O3-SiO2 system were prepared by rapid quen ching of the 1400 degreesC melts. Phase separation was induced by heat-trea tment at 600 degreesC for different exposure times and monitored qualitativ ely by an observation of Rayleigh scattering. The I-4(9/2) --> (2)p(1/2) tr ansition of Nd3+ around 23 300 cm(-1) recorded for the quenched samples wit hout heat-treatment was used to demonstrate that submicroscopic phase separ ation in the doped glasses occurs instantaneously upon quenching. The effec t of the Nd3+ concentration on this submicroscopic phase separation was inv estigated. (C) 2001 Elsevier Science B.V. All rights reserved.