In situ observation of pressure-induced crystallization from amorphous calcium carbonate

Abstract

In situ XRD observation of pressure-induced crystallization from amorphous calcium carbonate (ACC), which is a precursor of crystalline calcium carbonates, was performed using a multi-anvil system at BL NE5C of PF-AR. Time-resolved XRD patterns indicated that the crystallization from ACC to calcite and vaterite was very fast phase transition, for which it took about 3 min. Avrami plots imply that the nucleation rate of vaterite is higher than that of calcite. This result is consistent with the results from recovered experiments; the relative abundance of vaterite decreased with increased compression pressure.