An indirect approach to measure glass transition temperature in metallic glasses

Glass transition behavior of metallic glasses under some extraordinary conditions (such as under high pressures) remains unexplored. Conventional measurements of glass transition temperature, T-g, are very difficult to perform under these extraordinary circumstances. In the present paper, we introduce an indirect approach to characterize glass transition, using enthalpy recovery experiments. With annealing deeply relaxed glassy samples and subsequent DSC measurements, a variation of enthalpy change upon heating with annealing temperature can be obtained. The variation of enthalpy change, a signature of glass transition, was found to correlate well with the directly measured DSC curves for the glass transition. This unique method was successfully applied in determining Tg of several metallic glasses under hydrostatic high pressures and compression stresses.