Discontinuous behavior of Rayleigh relaxation in supersaturated aqueous NH4H2PO4 Solution

The algorithm of Rayleigh intensity correlation is employed for the elucidation of relaxa-tion time constants of the aqueous NHHPOsolution with various concentrations.The resultshows that there is a discontinuous（abrupt）increases in the relaxation time constant as the super-saturation state is reached.This quantity,the relaxation time constant,therefore,can be an orderparameter.Also discussed is the dependence of the relaxation time constant on the aggregationnumber n in（HPO）.This dependence is complicated and may be crucial in understanding theaggregation process in the supersaturation state.