Glasses are non equilibrium materials that develop by cooling of a supercooled liquid, where the rapidly increasing viscosity results in a kinetic arrest of long range atom rearrangements. During heating from glass state, different relaxations are thermally activated and display different relaxation spectrum. Here, we used one ultrafast nanocalorimetry to examine the evolution of multiple relaxations and discover the merging of the relaxation modes with increasing heating rates, resulting in step-like increases in both the supercooled liquid region and excess heat capacity. Our findings provide new insights on the evolution of the relaxation spectrum and the associated heterogeneous atomic motion.
- Meng Gao
- John H. Perepezko
