Fig. 6

a Plot of peak intensities as a function of time. Data were obtained from runs with the target temperatures varying in the range of 554–613 K. The heating rate was 80 K/min. The temperatures were maintained from 0 s after the initial temperature increase (shaded area). b Plots of ln ln(1/(1 − X)) as a function of ln (t) for the kinetic data at constant temperatures. The n values in the rate Eq. (1) correspond to the linear slope of these plots. The solid lines shown in this figure are based on a fixed n value of 0.05. The back-transition kinetics from Mg₂SiO₄ wadsleyite to olivine at 1273 K (n = 1.5) (Ming et al. 1991) is also provided for comparison (dashed line)