Molecular motions in a molecular crystal: Tetrachloro-m-xylene

In the present work we report a study of the molecular relaxation processes in tetrachloro-m-xylene in the solid state. The techniques of dielectric relaxation spectroscopy and thermally stimulated discharge currents were used in order to identify and characterise the different relaxation processes and it was found that a solid relator phase appears on heating al a temperature of similar to - 125 degrees C. It was also observed by thermally stimulated currents that a higher temperature relaxation occurs above similar to -15 degrees C. The attribution, at the molecular level, of this relaxation is not straightforward and it was suggested that it probably corresponds to the onset of the self-diffusional motions in the solid.