Dual effect of ZrO ₂ on phase separation and crystallization in Li ₂ O–Al ₂ O ₃ –SiO ₂ –P ₂ O ₅ glasses

ZrO2 is an effective nucleation agent for low-expansion lithium–aluminum silicate (LAS) glass–ceramic (GC) with high Al2O3 content. However, the effect of still not fully understood in LAS glasses low contents and P2O5. In this work, on phase separation crystallization Li2O–Al2O3–SiO2–P2O5 were investigated. The results revealed that significantly increased Tg temperature Li2SiO3 Li2Si2O5 crystals. Li3PO4 crystals precipitated preferentially glass containing 3.6-mol% ZrO2, wherein Zr was stable network no precipitation nanocrystals observed. Moreover, phosphate-rich phases as-quenched addition ZrO2. findings study a dual role First, acted as former rather than agent, increasing viscosity barrier through its strong connectivity. Second, combined non-bridging oxygen to form Si–O–Zr linkages, sufficient amount charge-balancing Li+ ions existed network, which promoted phases. It indicated incorporation contributes activation P2O5, thus contributing formation fine microstructure GCs.