Spectroscopic properties of rare earth doped germanate glasses

Structural and optical properties of Eu3+ doped barium-gallo-germanate glasses modified with antimony and tellurium oxides were investigated. Barium ions are gradually replaced by antimony and tellurium ions to create two glass series. Structural properties of prepared series were established with help of FT-IR spectroscopy, X-ray diffraction method and observation under Scanning Electron Microscope (SEM). MIR spectra of studied glasses indicate a tendency to glass structure polymerization through the observed shift of main band assigned to Ge-O-Ge and Ge-O bonds vibrations. Simultaneously luminescence spectrum of Eu3+ ion (Electric/Magnetic – ED/EM dipole transition intensity ratio) for both glass series presented the increasing tendency to ordering of Eu3+ local environment. It was also proved that tetrahedral [TeO4] units were created in glass structure which were modified with TeO2 when addition exceed 10 mol%. The result indicates decrease of ED/MD ratio as a function of TeO2 content above its 10 mol%.