Local Heating Transforms Amorphous Calcium Carbonate to Single Crystals with Defined Morphologies

The use of amorphous calcium carbonate (ACC) as a precursor phase affords organisms with outstanding control over the formation calcite and aragonite biominerals. Essential to this strategy is that ACC maintained within confined volumes in absence bulk water. This ensures undergoes pseudomorphic transformation organism can independently nucleation growth. However, comparable has proven hard achieve synthetic systems. Here, straightforward method demonstrated for controlling crystallization thin films which first triggered using heated probe, then growth sustained by incubating film at lower temperature. By growth, sub-millimeter single crystals be generated when where it desired, morphologies ranging from discs squares serpentine strips created, arrays formed. mechanism energetics are studied situ transmission electron microscopy continuity between front demonstrated. It envisaged applied large alternative functional materials form via phases.