Bi3+ doped Na2O-TiO2-P2O5 phosphate glasses: Insight into structural, physical, mechanical, thermal, chemical, crystallization, dielectric, and energy storage properties

Phosphate glasses hold promise for a variety of applications ranging from electrochemical cells to electro-optical devices. This paper details the elaboration and characterization of a series of Bi2O3 doped alkaline-phosphate glasses in the (55-x)Na2O-xBi2O3-5TiO2-40P2O5 system. A set of physical, structural, thermal, and electrical, characterizations have been carried out to understand the structural role of Bi2O3 in these glasses and provide insights into their overall stability and functional characteristics. As more Bi2O3 is incorporated into the glass up to 10 mol%, spectroscopy results showed local structural changes, with increased density, and glass transition temperature alongside enhanced mechanical properties and chemical durability. Additionally, the study involved the exploitation of heat treatment to induce the crystallization of vitreous samples through controlled crystallization. The 299.5 kJ/mol−1 energy of crystallization, signifies the amount of energy required for the transition from an amorphous to a crystalline state. The kinetics parameter identified the capacity for bulk nucleation in a single dimension of crystallite growth. The natures of the crystalline phases were determined with X-ray diffraction. Dielectric parameters and energy storage capacities were improved substantially with increasing Bi2O3 concentration, with a recoverable energy density peaked at 10.72 mJ/cm3 with 10 mol% Bi2O3, highlighting their potential for energy storage applications. A correlation between the thermal, dielectric, and structural properties of these glasses has been established.