Nagel scaling, relaxation, and universality in the kinetic Ising model on an alternating isotopic chain

The dynamic critical exponent and the frequency and wave-vector dependent s usceptibility of the kinetic Ising model on an alternating isotopic chain w ith Glauber dynamics are examined. The analysis provides a connection betwe en a microscopic model and the Nagel scaling curve originally proposed to d escribe dielectric susceptibility measurements of several glass-forming liq uids. While support is given to the hypothesis relating the Nagel scaling t o multiple relaxation processes, it is also found that the scaling function may exhibit plateau regions and does not hold for all temperatures.