Spinodal decomposition in a binary fluid

Abstract
Light scattering has been used to study a mixture of 3-methylpentane and nitroethane undergoing spinodal decompositon. The scattered intensity has been measured in absolute units allowing the first test of theory with no adjustable parameters. The measured structure factor does not evolve according to theory even when the initial fluctuations are taken into account. We believe the reason is that the evolving concentration field causes the sample temperature to change continuously throughout the decomposition process.