Temperature and Pressure Scaling of the α Relaxation Process in Fragile Glass Formers: A Dynamic Light Scattering Study

The dynamics of two fragile glass forming liquids was studied as a function of temperature and pressure using dynamic light scattering. On the basis of measured data we evaluated the pressure and temperature scaling of the alpha relaxation. All the isotherms can be superimposed and form a master curve when the reduced relaxation times are plotted versus reduced pressure. The Kohlrausch-Williams-Watts stretching parameter beta(KWW) is increasing with increasing temperature and decreasing pressure and plotted versus log follows a master curve at all temperatures and pressures studied.