Fig. 2: Evaluation of the non-equilibrium effective relaxation time τ_eff below T_g using different models.

Taking the present Ce-based MG with a fragility of 40.9 and a T_g of 410 K as an example, the τ_eff at ambient temperature is assessed using VFT^20,21,22, MYEGA²⁴, Parabolic²³, NM models^18,25, coupling model (CM)³³, and our proposed empirical equation. The empirical equation yields a result of ~1.14 years, which is within the same order of magnitude as the age of Ce-based MG. In contrast, the other models significantly overestimate the τ_eff, resulting in values that are vastly different from the actual age of the glass.