A new criterion for the glass-forming ability of liquids

Based on theoretical calculations using the fragility concept and the nucleation theory for a model glass-forming system, we propose a dimensionless criterion, ϕ, expressed by Trg(ΔTx/Tg)a, with Trg, the reduced glass-transition temperature, ΔTx, the width of the supercooled liquid region when heating a glass, Tg, the glass transition temperature, and a, the exponent. The application of this simple criterion to various glasses, including network, metallic, and molecular glasses (except pure water), indicates an excellent correlation between the critical cooling rate Rc and ϕ in a Log Rc–ϕ single master plot with a = 0.143.