Growth of Magnesium Carbonate Single Crystal in Supercritical Carbon Dioxide-Molten Sodium System

摘要

A novel crystal growth method has been developed to grow single crystals of magnesium carbonate from molten sodium. Single crystals of magnesium carbonate with a size up to 1.5 mm were grown at 550 C in a closed vessel consisting of an appropriate amount of magnesium carbonate powder, metallic sodium, and carbon tetrachloride. The X-ray rocking curve of the magnesium carbonate single crystal has a full-width at half-maximum (fwhm) of 0.043°, indicating the high quality of the crystal. The possible growth mechanism of the single crystals was discussed based on the pyrolysis and recrystallization of MgCO_3 in molten sodium environment at reaction temperatures.