Nucleation, Growth, and Scaling in a Pressure-Induced First-Order Phase Transformation: RbI

Abstract

We have investigated the kinetics of the NaCl-to-CsCl phase transformation in RbI at room temperature ($P_c\approx 3.5$ kbar) by monitoring the time-dependent changes in neutron powder diffraction peaks. Above $P_c$ the rate of growth of the stable phase increases with increasing pressure, but the growth curves display a universal shape, consistent with the Kolmogorov model of nucleation and growth, when plotted versus a scaled time parameter $\tau =\frac{t}{{\tau }_0}\mathrm{}\left(P\right)\mathrm{}$.