Statistical structure analysis of GeO2 modified Yb3+: Phosphate glasses based on Raman and FTIR study

Structural modification of conventional Yb3+ doped phosphate glass by GeO2 was shown to significantly improve both thermal and spectroscopic properties, namely, transition temperature, coefficient of thermal expansion, effective line width, Stark splitting, and fluorescence lifetime. Raman and IR spectroscopic techniques, in conjunction with a statistical analysis method, were used to determine plausible network structure units, or “genes”, which had significant effects on the properties, specifically the distributions of tetrahedron units ([4]Ge-O-[4]Ge, [4]Ge-O-P, P-O-P) and octahedron units ([6]Ge-O-[6]Ge) in the GeO2-containing glasses. The use of statistical approach enabled us to build linear mathematic functions of network structure units - property relationships, or models, and the model predictions were closely matched with the measured values. The outcome demonstrates that statistically derived results from Raman and/or IR spectra can be used to aid glass design, achieving target properties.