By measuring the complex dielectric susceptibility over 15 decades in frequency we compare the α relaxation in low-molecular-weight glass-forming liquids and polymers. To describe the scaling behavior of the α relaxation, a minimal set of four parameters is necessary, the mean relaxation time, the dielectric strength, and two shape parameters, describing the low- and high-frequency wings of the relaxation function, in pronounced contrast to a recently published scaling function.

• Received 25 April 1991

DOI:https://doi.org/10.1103/PhysRevLett.67.999