Photon correlation spectroscopy of vitreous ZnCl2 in the glass transition region

Measurements of photon correlation spectroscopy (P.C.S.) are performed on vitreous ZnCl2 above the glass transition. The results show a correlation function that decays with a single relaxation time ζ. This latter exhibits a time dependence typical of many physical quantities in glassy systems above Tg. A tentative interpretation of the data in the framework of current theories is given.