Crackling of a coagulating suspension.

A way of analyzing the intermittent dynamics of nonstationary systems is introduced. It is used to study the dynamics of a concentrated suspension while it is flocculating, probed by diffusing wave spectroscopy. When the repulsion interactions between the particles are slowly decreased their motion appears to be intermittent. It is characterized by rapid crackling periods, separated by arrested dynamics. Duration of the crackling periods exhibit a power-law distribution function.