Influence of Al2O3 Content on the Structural Network and Thermal Stability of Lithium Borate Glasses

The impact of Aluminum oxide (Al2O3) addition on thermal stability and structural networks present within lithium borate glass defined by the mixed composition of the simple ternary Li2O–Al2O3–B2O3 system. This approach intends to separate the specific structure of Al2O3 contributions from any potential impacts of additional dopants or the complex chemistry of glasses studied previously. Glasses with variable amounts of Al2O3 were prepared through a standard melt-quench technique. Structural modifications were investigated using X-ray diffraction and Fourier transform infrared spectroscopy, with particular emphasis placed on the evolution of three-coordinated boron (BO3) and four-coordinated boron (BO4) units and the formation of four-coordinated aluminum (AlO4) tetrahedra.Differential scanning calorimetry was used to evaluate thermal stability and both the glass transition temperature, crystallization temperature, and thermal stability window. Higher Al2O3 contents translated into enhanced network connectivity, more pronounced structural densification, and greater thermal stability. The results give an improved understanding of the structure-property relationship of this type of glass by illustrating the relationship between composition and properties. The findings support the use of the aluminate lithium borate glasses for applications requiring greater resistance to heat than what current materials can provide.