Single Crystal Growth of Calcium Carbonate (Synthetic Calcite). Phase 1, Final Report

摘要

The feasibility of calcite single crystal growth from a Li2CO3 solvent using the Heat Exchanger Method (HEM) was demonstrated. It was observed that a CO2 atmosphere is necessary to prevent decomposition of calcium carbonate (CaCO3). Under flowing CO2 at 1 atm, some decomposition to CaO was evident; however, this secondary phase was rejected from the solid-liquid interface during HEM growth; only microscopic particles were observed within the crystals. With a higher CO2 overpressure the decomposition can be eliminated and the particulates will not be incorporated in the crystals. The reuseability of platinum crucibles was demonstrated during the program and no platinum contamination of the grown crystals was observed.