Transparent surface and bulk crystallized glasses with lanthanide tellurite nanocrystals

Abstract

Crystallization behavior of BaO-Ln2O3-TeO2 glasses (Ln = La, Pr, Sm, Eu, Er) 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 Ln2Te6O15 or Ln2Te5O13 nanocrystals (∼50 nm sizes) were successfully prepared for the first time. The crystallization mechanism depends strongly on the lanthanide species: surface crystallization (∼15 μm) 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.