Crystallization Driving Force of Supercooled Oxide Liquids

The driving force for crystallization (Δμ) can be calculated by the Gibbs free energy equation, which relies on heat capacity (Cp) data. However, such data may be unavailable, which led several authors to propose new equations to estimate Δμ without Cp. Two relevant expressions are the Turnbull and Hoffman equations, which are assumed to act as boundaries for the actual value of Δμ. The aim of this work was to test whether this assumption is valid for 65 oxide liquids, including glass formers and reluctant glass‐forming compositions. These equations do not act as boundaries, but the majority of the glass formers do have a driving force within these boundaries. Furthermore, this work tested a Δμ expression proposed by Gutzow and Dobreva that is a generalization of the Turnbull and Hoffman equations. This equation described the actual values of Δμ really well for all compositions with only one additional parameter: a0. Finally, a new expression to estimate a0 was obtained based on the results of this work.