Abstract

Physical vapor deposition (PVD) procedures based on the fine control of substrate temperature and deposition rate have proven successful in producing glassy materials, named ultrastable, that exhibit extraordinary thermodynamical and kinetic stability. A lot of theoretical and experimental efforts have been put in relating the energy associated to a microscopic configuration of the glass, hence the stability, to its elastic properties. To pursue this correlation, we have investigated the vibrational dynamics [1-3] of a prototypical glass-forming drug, Indomethacin (IMC), as a function of its degree of stability. Two of the major challenges are the limited sample thickness (from few hundreads nm to microns), preventing the application of standard techniques, and the lack of characterization of the optical properties, i.e. the refractive index.

© 2015 IEEE