Abstract
The study investigates the molten binary xLi2O-(100-x)GeO2 system (where x varies from 0 to 67 mol%) at 1573 K using in situ high-temperature Raman spectroscopy, classical molecular dynamics simulations, and quantum chemistry ab initio calculations. A comprehensive quantitative analysis of the local structure of the melt is presented, focusing on the correlation between local structure variations and macroscopic properties. The results show that the melts are composed of four-fold coordinated [GeO4] tetrahedra, and the anomalous density behavior is related to the formation of smaller [GeO4] three-member rings. A practical method was developed to correct Raman spectra by compensating for the influence of Raman scattering cross-sections, thereby facilitating precise quantification of Qi species distribution. This distribution was subsequently utilized to establish a viscosity model, demonstrating that the Qi species contribution to viscosity decrease in the order Q4 > Q3 > Q2 > Q1. These findings provide essential insights into the structural evolution of xLi2O-(100-x)GeO2 melts and propose a framework for predicting macroscopic properties based on local structural parameters.