Glass transitions and dynamics in thin polymer films: Dielectric relaxation of thin films of polystyrene

The glass transition temperature T-g and the temperature T-alpha corresponding to the peak in the dielectric loss due to the cu process have been simultaneously determined as functions of film thickness d through dielectric measurements for polystyrene thin films supported on glass substrate. The dielectric loss peaks have also been investigated as functions of frequency for a given temperature. A decrease in T-g was observed with decreasing film thickness, while T-alpha was found to remain almost constant for d>d(c) and to decrease drastically with decreasing d for d