Transparent surface and bulk crystallized glasses with lanthanide tellurite nanocrystals

Crystallization behavior of BaO-Ln(2)O(3)-TeO2 glasses (Ln=La, Pr, Sm, Eu, Pr) was examined to prepare transparent crystallized glasses consisting of lanthanide tellurite crystals (Te4+ crystalline compounds) with low phonon energies, Transparent crystallized glasses with fluorite-type Ln(2)Te(6)O(15) or Ln(2)Te(5)O(13) nanocrystals (similar to 50 nm sizes) were successfully prepared for the first time. The crystallization mechanism depends strongly on the lanthanide species: surface crystallization (similar to 15 mum) is dominant in La3+ and Pr3+ containing glasses, but homogeneous nucleation occurs easily in Sm3+, EU3+ and Er3+ containing glasses, giving transparent bulk crystallized glasses. These transparent nano-crystallized glasses are applicable to fabrication of optical amplified waveguides or Bragg grating fibers.