Pellegrino Musto

Reversible effects in IR absorption peaks of SiC:H, measured as a function of the temperature

Abstract We performed an investigation of the variations of the IR absorption peaks as a function of the annealing temperature, Ta, in a-SiC:H alloys. The samples were grown by plasma enhanced chemical vapor deposition using a gas mixture of SiH4+C2H2. We followed the evolution of several peaks during the thermal cycle (i.e. heating from 25 to 250 °C followed by cooling under identical conditions). The analysis of some characteristic parameters of the IR peaks evidences the reversible behavior of the IR absorption as a function of Ta cycles. The link with similar reversible resistivity effects is studied.

1,2-dichloroethane conformation and molecular organization in syndiotactic polystyrene gels

The conformational equilibrium of 1,2-dichloroethane (DCE) in syndiotactic polystyrene (sPS)/DCE gels has been investigated by using Fourier transform infrared spectroscopy. Results show that the fraction of DCE in the trans conformation (X T ) increases with increasing polymer concentration. From these X T values, by assuming that the crystalline phase in the gel presents the clathrate structure, the amount of DCE included in the crystalline phase and the fraction of polymer included in the crystalline phase were evaluated as a function of the gel composition.