Effect of fragility on the stability and thermodynamic properties of amorphous Te-Ge films

Amorphous materials exhibit great a range in their properties due to their ability to possess different local structures. Depending on the local structure, amorphous materials can achieve a wide range of stabilities, both above and below the traditional fast-cooled materials. We measured this stability primarily by examining the thermodynamic properties of the material, including using fast-scanning calorimetry to measure the glass transition onset and magnitude. In this work, we show changes in the stability of amorphous as-prepared TeGe films prepared with different growth parameters. By varying these conditions we are able to achieve understable, normally stable, and ultrastable films, even at the same composition. We further compare the results of different TeGe compositions, and therefore fragility, on the ability to form glasses of various stabilities.