Spectroscopy study on the nucleation kinetics of ZrTiO4 in a lithium alumosilicate glass

• We study the nucleation of ZrTiO4 in a Li-alumosilicate glass by optical spectroscopy.
• Increase in extinction correlates with increase in crystal volume fraction of ZrTiO4.
• Steady state nucleation process of ZrTiO4 during early stage of heat treatment
• Maximum number density of ZrTiO4 reaches up to 1023 crystals per m3.
• Nucleation proceeds at a rate close to 1019 crystals per m3 and second.

The nucleation kinetics of zirconium titanate ZrTiO4 in a multi-component lithium alumosilicate (LAS) glass was quantified by analysis of spectroscopic data from the UV–Vis-region. Using Mie theory the scattering power of nano-sized ZrTiO4 crystals embedded in the glassy matrix as well as their absorptive properties were determined and separated from the individual absorbance of various dilute Fe- and Ti-species in nucleated LAS glasses. Extinction coefficients, elaborated with the assumption of constant crystal size (≈ 4 nm) revealed that the ZrTiO4 volume fraction reached its final value for a dwell time of ≈ 120 min at 1018 K. The power of the transformation rate (≈ 1.3) as analyzed by JAMK equation was attributed to a steady state crystal nucleation process. For a final crystal volume fraction of 1% ZrTiO4, the maximum number density Nv ≈ 3 × 1023 m− 3 and the stationary nucleation rate Iss ≈ 5 × 1019 m− 3 s− 1 was determined.