Incorporation of as-Prepared Eu³⁺-doped Lanthanum Niobate Nanoparticles in Tellurite Glasses

A direct-doping method was tested to design new composite-glasses by incorporating lanthanum niobate nanocrystals (NC) in tellurite glasses. NC powder were grinding with glass powder before heating-quenching, with the main investigation approached of best parameters for NC suitable homogenization but limited dissolution. Thermal analysis signalizes that prior heat-treatment of NC promotes higher transparency and limits NC dissolution. These materials with visually detectable NC aggregates exhibited glass transition temperatures close to the starting glass. LaNbO₄ phase was hardly detected by X-ray diffraction because of the low weight ratio and partial dissolution but the monoclinic polymorph could be identified for lower time. UV-visible-NIR transmission spectra also related progressive lower transparency with light scattering of NC aggregates. Photoluminescence suggest that lower times allowed to ensure the NC environment with lower crystallinity around Eu³⁺-ions in final composite-glass. These results pave the way for designing new materials containing NC not achievable by conventional nucleation-growth methods.

Keywords:
Direct-doping; TeO₂; Luminescence; Composite-glass; LaNbO₄