Glassy dynamics in nanometer thin layers of polystyrene

Broadband Dielectric Spectroscopy (BDS) and Ellipsometry are combined to study the glassy dynamics of nanometric layers (≥ 5 nm) of polystyrene. For the former, two types of sample arrangement are applied, that is, the conventional method where evaporated metal electrodes are used and a novel technique in which insulating silica nanostructures serve as spacers between highly conducting doped silicon counter electrodes. Within the limits of the experimental accuracy (± 2  K) both approaches, BDS and Ellipsometry, deliver the coinciding result that – compared to the bulk – the glassy dynamics is not shifted. Furthermore the dielectric measurements do not indicate any broadening of the relaxation time distribution function, independent of the sample geometry employed.