Up to this moment, the dynamics of glasses have been measured in a very short temperature range, limited by their time-scale. At low temperatures, the dynamics of glasses are too slow to be measured and at too high temperatures, the glass relax into the equilibrium supercooled state before being possible to extract any information by conventional techniques.
In the Group of Nanomaterials and Microsystems of the Physics Department at the Universitat Autònoma de Barcelona, we have been able to access the relaxation dynamics of glasses with different stability, from conventional glasses to ultrastable glasses grown by physical vapour deposition, by using ultra-fast heating-rate nanocalorimetry.
In this study, we have been able to determine the non-Arrhenius nature of the relaxation process of glasses along a very wide temperature range, in contrast with the Arrhenius behaviour that was considered to hold in the short temperature range typically explored by conventional techniques.
Also, we have observed how these glasses, with very different thermodynamic stability, exhibits density-scaling relationships that were verified for supercooled liquids measured at different temperatures and pressures.
This work was recently published in Scientific Reports, and is available as an open-access paper clicking here.