The present study investigates the influence of lead incorporation on the crystallization kinetics and thermal behavior of Se87.5Te10Pb2.5 glass prepared by the melt-quenching technique and characterized by differential scanning calorimetry over heating rates of 5–99 K·min−1. Nonisothermal kinetic parameters were evaluated using model-free isoconversional methods, namely the Friedman and Vyazovkin approaches, while the Matusita model was employed to gain insight into the crystallization dimensionality. Complementary isothermal simulations were used to support the kinetic interpretations. The apparent activation energy exhibits a systematic decrease with increasing temperature and crystallized fraction, suggesting a multi-stage crystallization process. At lower temperatures, crystallization is dominated by three-dimensional growth with instantaneous or diminishing nucleation, whereas higher temperatures favor a transition toward lower-dimensional growth. The evolution of the Avrami exponent indicates the coexistence of surface and bulk crystallization mechanisms, reflecting a gradual shift from nucleation-controlled to growth-controlled kinetics. Thermal metrics, including the glass transition temperature, the width of the supercooled liquid region, the Saad–Poulin s-parameter, the reduced glass transition temperature, and the Hruby number, exhibit a consistent increase with heating rate, reflecting kinetically induced delay against crystallization. Overall, the kinetic and thermal analyses provide a coherent description of the crystallization behavior of Se87.5Te10Pb2.5 glass under nonisothermal conditions, highlighting the role of Pb incorporation in modifying both crystallization pathways and apparent thermal stability demonstrates that Pb incorporation promotes structural relaxation and controlled crystallization, improving the thermal endurance of Se–Te–Pb glasses, which is relevant to thermal-stability considerations discussed in the context of optical and phase-change materials.
Mahdi Al-Maghrabi (Thu,) studied this question.