Figure 1: Time evolution of the dielectric function in comparison with the growth of the adsorbed layer for PS97 during annealing at 423 K.
From: The lifetime of the deviations from bulk behaviour in polymers confined at the nanoscale
Inset: the dielectric strength, Δɛ (black circles), of polymer nanocapacitors (aluminium/PS/aluminium) decreases on isothermal annealing at Tg+50 K. For a 21-nm-thick film, the reduction rate of Δɛ is constant at short times t<ton≈2×103 s, where the decay speeds up by 60%, till finally recovering its starting value after toff≈3×104 s. We extracted the traces of the higher rate process Δɛhigh(t) (red diamonds), subtracting the linear contribution at Δɛ(t<ton). The time evolution of Δɛhigh(t) matches the relative increase of the high frequency value of the capacitance, C∞ (green dots, measured at 44 nm and normalized between the starting and final value of Δɛhigh to ease comparison), and the growth of the thickness of the irreversibly adsorbed layer, hads, (semi open blue hexagons) in films annealed for different time at the same temperature of the isothermal experiments. Error bars for hads take into account the uncertainties in the determination of film thickness from its geometrical capacitance, in the presence of an oxide layer on the aluminium surfaces.
