Effects of Temperature and Alkali Metal Ions on the Structure and Crystallization Process of Amorphous Magnesium Carbonate

The effects of temperature and alkali metal ions on the structure and crystallization process of amorphous magnesium carbonate（AMC） were investigated using synchrotron X-ray total scattering and X-ray absorption fine structure（XAFS） spectroscopy. The pair distribution function（PDF） analysis revealed that no substantial structural differences were observed between AMCs synthesized at 20℃, 60℃, and 80℃. The presence of Na or K ions in the solution promotes the formation of nesquehonite, but the presence of Rb or Cs ions inhibits the long-range ordering of atoms and suppresses crystallization. These findings indicate that alkali metal ions play an important role in controlling the crystallization of AMC.