Exploring an operational strategy for South African electron microscopy facilities
- Authors: Olivier, Ezra Jacobus
- Date: 2018
- Subjects: Electron microscopy , Production management -- South Africa Strategic planning -- South Africa Performance -- Management -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/34465 , vital:33383
- Description: Electron microscopy is a versatile and widely used technique in the fields of physical and biological sciences. It is a strategic enabling resource needed for innovative science and technology research to occur in the areas of nanotechnology developments. The availability of these resources worldwide are typically seen within dedicated shared electron microscopy research facilities due to the costs and operational support required in acquisition and operation of these instruments. A consequence of this is that these facilities require carefully designed operational management approaches. One of the pertinent questions within the electron microscopy community of South Africa is if electron microscopy core facilities in the country could be judged successful in the execution of their operations. Some concerns related to the skills present at these facilities as well as the management philosophy of these facilities have been raised. This study aims to investigate these factors within an South African context. In the current study, a combination of the quantitative and qualitative research paradigms was used. A survey was conducted amongst South African electron microscopy core facility users to measure their level of satisfaction and needs related to electron microscopy core facilities in South Africa. Furthermore, insights where gathered from experienced managers of electron microscopy core facilities nationally and internationally using a case study based approach. The findings were combined and compared to identify the critical factors needed to optimise the operational approaches of electron microscopy facilities in South Africa and to develop a standardised approach in judging a facility’s performance. The study provided valuable insights as to the level of satisfaction present within the electron microscopy community of South Africa related to the use of electron microscopy core facilities in the country. It also yielded important information regarding the areas where the highest need for improvement lies. The outcome of the study provides a standardized approach to the operations of electron microscopy research facilities in South Africa and their performance evaluation. A possible limitation to the study is the population sample used for the survey. The survey was completed by existing electron microscopy core facility users in South Africa. However, the experiences and needs of less frequent or potential new users of such facilities were not probed. Thus, the developed strategy may lack factors related to growing the field in South Africa if the needs of inexperienced users are not taken into account.
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- Date Issued: 2018
Analysis of the extended defects in 3C-SiC
- Authors: Olivier, Ezra Jacobus
- Date: 2008
- Subjects: Crystals -- Defects , Crystallography , Silicon carbide
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10525 , http://hdl.handle.net/10948/730 , Crystals -- Defects , Crystallography , Silicon carbide
- Description: The dissertation focuses on the analysis of the extended defects present in as-grown and proton bombarded β-SiC (annealed and unannealed) grown by chemical vapour deposition (CVD) on (001) Si. The proton irradiation was done to a dose of 2.8 × 1016 protons/cm2 and the annealing took place at 1300°C and 1600°C for 1hr. The main techniques used for the analysis were transmission electron microscopy (TEM) and high resolution TEM (HRTEM). From the diffraction study of the material the phase of the SiC was confirmed to be the cubic beta phase with the zinc-blende structure. The main defects found in the β- SiC were stacking faults (SFs) with their associated partial dislocations and microtwins. The SFs were uniformly distributed throughout the foil. The SFs were identified as having a fault vector of the type 1/3 <111> with bonding partial dislocations of the type 1/6 <121> by using image simulation. The SFs were also found to be predominantly extrinsic in nature by using HRTEM analysis of SFs viewed edge-on. Also both bright and dar-field images of SFs on inclined planes exhibited symmetrical and complementary fringe contrast images. This is a result of the anomalous absorption ratio of SiC lying between that of Si and diamond. The analysis of the annealed and unannealed irradiated β-SiC yielded no evidence of radiation damage or change in the crystal structure of the β-SiC. This confirmed that β-SiC is a radiation resistant material. The critical proton dose for the creation of small dislocation loops seems to be higher than for other compound semiconductors with the zinc-blende structure.
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- Date Issued: 2008