Calcium Carbonate Nanocrystal Growth and Formation on Substrate by Thermal Chemical Vapor Deposition at Different Pre-Cursor Concentration

Abstract

Recent observations of crystallization by thermal chemical vapor deposition systems indicate that the classical mechanism of nucleation and growth is followed. Information on aragonite nanocrystal growth and formation on substrate have been lacking due to the lack of reports on diffusional growth that can observe calcium carbonate nucleation processes in thin film formation. This report is important due to the additive-free method able to grow stable single-phase nanocrystals without the presence of other phases, amorphous or impurities. This work demonstrates homogeneous nucleation occurred in gas phase reaction in a constant flow of carbon dioxide gas (100 sccm) with optimally 0.5 M calcium chloride precursor in atmospheric pressure at 400 °C resulting in a calculated crystallite size of 27.8 nm. X-ray diffraction and energy dispersive spectrometer confirm the presence of calcium carbonate nanocrystal, whereas its structural changes are observed by its micrograph from field emission scanning electron microscope. The aim is to convey its importance in gaining control of aragonite nanocrystal morphology and structural properties, and thus generate nanocrystals with controlled phase. This work may contribute to development of more sensitive and crucial applications of calcium carbonate nanocrystal thin film such as in biosensors and biomedical.