Pressure-induced polyamorphism and formation of 'aragonitic' amorphous calcium carbonate

Pressed for time: Amorphous calcium carbonate (ACC) undergoes a reversible amorphous-amorphous phase transition at 10 GPa, adopting an aragonite-like local order. This result suggests a mechanism by which Mg²⁺ - a cation with smaller ionic radius than Ca²⁺ - modifies the local order of ACC to an aragonite-like order by helping to decrease the molar volume of the amorphous phase.4 page(s