The effect of rare earth (RE3+) ionic radii on transparent lanthanide-tellurite glass-ceramics: correlation between ‘hole-formalism’ and crystallization

Transparent LGTT GCs contain La 2 Te 6 O 15 and Gd 2 Te 6 O 15 crystallites. Dopant Ce 3+ /Pr 3+ /Nd 3+ ions occupy La site of La 2 Te 6 O 15 phase, transforming GCs opaque. Hole-pairs Eu 3+ :Tb 3+ /Sm 3+ :Dy 3+ occupy Gd site in Gd 2 Te 6 O 15 , and retain transparency in GCs.