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

• Published in: CRYSTAL RESEARCH AND TECHNOLOGY
• Main Authors: Sulimai, Nurul Hidah; Jafar, Salifairus Mohammad; Khusaimi, Zuraida; Malek, Mohd. Firdaus; Abdullah, Saifollah; Mahmood, Mohamad Rusop
• Format: Article; Early Access
• Language: English
• Published: WILEY-V C H VERLAG GMBH 2024
• Subjects: Crystallography
• Online Access: https://www-webofscience-com.uitm.idm.oclc.org/wos/woscc/full-record/WOS:001262349100001

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 degrees 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. Novel no additive thermal chemical vapor deposition of +/- 0.4-0.6 nm stable single-phase aragonite nanocrystalline film is synthesized and hence suitable for further sensitive applications such as biosensor and biomedical. This is the first time it has been reported that calcium carbonate nanocrystal is deposited on thin film and its mechanism explained. Roles of precursor concentration in nanocrystalline formation have been evaluated and reported. This is the first time the optimal concentration of CaCO3 nanocrystal formation is reported yet. Calcium chloride (CaCl2) precursor molar concentration limit and most optimal is 0.5 M else formation of amorphous calcium carbonate is formed. image