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 (${P}_{c}\ensuremath{\approx}3.5$ 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 $\ensuremath{\tau}=\frac{t}{{\ensuremath{\tau}}_{0}}(P)$.