Phase transitions and aging phenomena in dielectriclike polymeric materials investigated by ac measurements

We study the glassy phase of a thin polydimethylsiloxane film by high sensitivity dielectric measurements. We can locate its glass and melting transition temperatures and discuss its aging properties and frequency dependencies. Our data are framed into the general picture of glassy phenomena and compared, in particular, to the so called universal dielectric response model of frequency dispersion. The effect of a dc bias is also analyzed. (c) 2007 American Institute of Physics.