Growth and doping of fullerene single crystals

• Main Author: Pang, Geraldine Qiao Yi
• Other Authors: Christian Leo Kloc
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Science
• Online Access: http://hdl.handle.net/10356/44623
• Institution: Nanyang Technological University

Fullerene single crystals were obtained through physical vapor transport (PVT) and solution growth. The equipment used for the PVT grown crystals was a vacuum furnace and the equipments used for solution growth were personally set up by the author. The solvent used for solution growth is commercially available naphthalene which came in the raw form of moth balls. It is the first known attempt made to grow fullerene single crystals with naphthalene solvent as there were no literature works on it previously. Crystals from the PVT method and solution growth method were compared against each other through a series of characterization methods. The crystals obtained from solution growth were predominantly hexagonal-shaped and the largest crystal was 0.659mm while PVT crystals had a variety of shapes. After varying certain parameters of the solution growth experiment, the crystals grown from naphthalene solvent were found to be of comparable surface quality when viewed under a scanning electron microscope. Raman and Fourier Transformed Infra-Red spectroscopy was also applied to identify the chemical bonds present in both samples and the spectra of both crystals from the different growth methods were similar, indicating that the type of bonds present in these crystals are identical. The powder x-ray diffraction showed that the solution phase grown and PVT grown crystals were of face-centered cubic phase. In addition, SCXRD performed suggested that crystals from solution growth could be of rhombohedral phase and the PVT grown crystals were of face-centered cubic phase. The anomaly in results is due to twinning along the c-direction of the solution grown C60 single crystals resulting in the discrepancy. C60 crystals from the solution growth and PVT methods are essentially both FCC phase but SCXRD helped to reveal the twinning phenomenon in the solution grown crystals which was largely absent in PVT grown crystals.