Chong Yuen Tung = 硅化鐵薄膜的相和微觀結構 / 莊宛曈. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 63-65). / Text in English; abstracts in English and Chinese. / Chong Yuen Tung = Gui hua tie bo mo de xiang he wei guan jie gou / Zhuang Wantong. / Abstract --- p.i / 摘要 --- p.ii / Acknowledgment --- p.iii / Table of contents --- p.iv / List of Figures --- p.viii / List of Tables --- p.x / Chapter CHAPTER 1: --- Introduction --- p.1 / Chapter CHAPTER 2: --- Background --- p.4 / Chapter 2.1 --- Phases of crystalline FeSi2 --- p.4 / Chapter 2.2 --- Electronic structure of β-FeSi2 --- p.7 / Chapter 2.3 --- Orientation relationship between β-FeSi2 and Si --- p.8 / Chapter CHAPTER 3: --- Instrumentation --- p.10 / Chapter 3.1 --- Metal vapor vacuum arc ion source implantation --- p.10 / Chapter 3.2 --- Rutherford backscattering --- p.12 / Chapter 3.3 --- Transmission Electron Microscopy (TEM) --- p.13 / Chapter 3.3.1 --- Principles of TEM --- p.13 / Chapter 3.3.2 --- Electron specimen interaction and contrast --- p.14 / Chapter 3.3.3 --- Electron Diffraction --- p.15 / Chapter 3.3.4 --- Sample Preparation --- p.17 / Chapter 3.3.4.1 --- Plan-view sample --- p.17 / Chapter 3.3.4.2 --- Cross-section sample --- p.17 / Chapter CHAPTER 4: --- FeSi2 films fabricated by ion implantation --- p.18 / Chapter 4.1 --- Introduction --- p.18 / Chapter 4.2 --- Experimental details --- p.18 / Chapter 4.3 --- Ion energy series --- p.19 / Chapter 4.3.1 --- As-implanted sample --- p.19 / Chapter 4.3.1.1 --- Results --- p.20 / Chapter 4.3.1.2 --- Discussions --- p.20 / Chapter 4.3.2 --- Annealed samples --- p.24 / Chapter 4.3.2.1 --- Morphology of the annealed samples and the damage on Si substrate --- p.24 / Chapter 4.3.2.2 --- Identification of the FeSi2 phase and their orientation relationship with the Si matrix --- p.24 / Chapter 4.3.2.3 --- Photoluminescence of the samples --- p.26 / Chapter 4.3.2.4 --- Discussions --- p.26 / Chapter 4.4 --- Ion dosage series --- p.31 / Chapter 4.4.1 --- Results --- p.31 / Chapter 4.4.2 --- Discussions --- p.32 / Chapter 4.5 --- Summary --- p.36 / Chapter CHAPTER 5: --- Effect of post annealing on the phase and microstructure of FeSi2 --- p.37 / Chapter 5.1 --- Introduction --- p.37 / Chapter 5.2 --- Experimental details --- p.37 / Chapter 5.3 --- The correlation between microstructure of FeSi2 synthesized under different annealing conditions and their PL --- p.38 / Chapter 5.3.1 --- RTA series --- p.38 / Chapter 5.3.1.1 --- Results --- p.38 / Chapter 5.3.1.2 --- Discussions --- p.39 / Chapter 5.3.2 --- FA series --- p.42 / Chapter 5.3.2.1 --- Results --- p.42 / Chapter 5.3.2.2 --- Discussions --- p.44 / Chapter 5.3.3 --- RTAFA series --- p.45 / Chapter 5.3.3.1 --- Results --- p.45 / Chapter 5.3.3.2 --- Discussions --- p.45 / Chapter 5.4 --- The existence of alpha phase and its special shape --- p.51 / Chapter 5.4.1 --- Results --- p.51 / Chapter 5.4.2 --- Discussions --- p.52 / Chapter 5.5 --- The existence of gamma phase in 1050°C furnace annealed sample / Chapter 5.5.1 --- Results --- p.56 / Chapter 5.5.2 --- Discussions --- p.57 / Chapter 5.6 --- Summary --- p.59 / Chapter CHAPTER 6: --- Conclusions --- p.61 / References --- p.63

Digitized by Kansas Correctional Industries

Typescript. / Digitized by Kansas Correctional Industries

by Chen Dihu. / "November 1999." / Thesis (Ph.D.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (p. 160-173). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Yuen, Ying Kit. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 90-96). / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Introduction to Electron Field Emission --- p.1 / Chapter 1.2 --- Theory of Electron Field Emission --- p.4 / Chapter 1.3 --- Fowler Nordheim Model for Electron Field Emission in Metals --- p.5 / Chapter 1.4 --- Factors Affecting the Field Emission Properties --- p.7 / Chapter 1.4.1 --- Surface Morphology --- p.7 / Chapter 1.4.2 --- Electrical Inhomogeneity --- p.7 / Chapter 1.5 --- Goal of this Project --- p.9 / Chapter Chapter 2 --- Sample Preparation and Characterization Methods / Chapter 2.1 --- Sample Preparation --- p.11 / Chapter 2.1.1 --- MEVVA Ion Implantation System --- p.13 / Chapter 2.1.2 --- TRIM Simulation --- p.17 / Chapter 2.1.3 --- Implantation Conditions --- p.19 / Chapter 2.2 --- Characterization Methods --- p.21 / Chapter 2.2.1 --- AFM - Atomic Force Microscopy --- p.21 / Chapter 2.2.2 --- C-AFM ´ؤ Conducting Atomic Force Microscopy --- p.23 / Chapter 2.2.3 --- RBS - Rutherford Backscattering Spectrometry --- p.23 / Chapter 2.2.4 --- TEM - Transmission Electron Microscopy --- p.26 / Chapter 2.2.5 --- Field Emission Measurement --- p.27 / Chapter Chapter 3 --- Field Emission Properties of Co-Si02 / Chapter 3.1 --- Introduction --- p.29 / Chapter 3.2 --- RBS results --- p.30 / Chapter 3.3 --- Experimental results of as-implanted Co-SiO2 samples --- p.32 / Chapter 3.3.1 --- AFM and results --- p.32 / Chapter 3.3.2 --- Field emission properties of as-implanted Co-Si02 --- p.35 / Chapter 3.4 --- Step-like and jump-like features in the J-E plots --- p.39 / Chapter 3.5 --- Chapter Summary --- p.43 / Chapter Chapter 4 --- Field Emission Properties of Fe-SiO2 / Chapter 4.1 --- Introduction --- p.45 / Chapter 4.2 --- RBS results --- p.46 / Chapter 4.3 --- Experimental results of as-implanted Fe-SiO2 samples --- p.48 / Chapter 4.3.1 --- AFM and results --- p.48 / Chapter 4.3.2 --- Field emission properties of as-implanted Fe-SiO2 --- p.51 / Chapter 4.3.3 --- Comparison with as-implanted Co-SiO2 --- p.54 / Chapter 4.4 --- Experimental results of annealed Fe-SiO2 samples --- p.57 / Chapter 4.4.1 --- Annealing conditions --- p.57 / Chapter 4.4.2 --- AFM and C-AFM results --- p.57 / Chapter 4.4.3 --- TEM Images --- p.62 / Chapter 4.4.4 --- Field emission properties of annealed Fe-SiO2 --- p.68 / Chapter 4.5 --- Step-like and jump-like features in the J-E plots --- p.81 / Chapter 4.6 --- Field Emission Images --- p.84 / Chapter 4.7 --- Chapter Summary --- p.85 / Chapter Chapter 5 --- Conclusion & Future Plan --- p.87 / Reference --- p.90 / Appendix / Chapter A. --- Derivation of the Fowler Nordheim Equation --- p.97

La réponse à l’intervention (RAI) est un processus de prise de décision informé par des données qui, à l’aide de l’enseignement et des interventions efficaces, prévient les difficultés de lecture et d’écriture, et améliore ces habiletés pour tous les élèves. Depuis quelques années, plusieurs écoles francophones de la province du Québec implantent la RAI. Le processus des connaissances à la pratique a été choisi pour guider certaines de ces écoles dans leur implantation. Après quelques années d’implantation, ces écoles ont maintenant atteint la phase de ce processus qui vise à surveiller l’utilisation des connaissances. En d’autres mots, cela consiste à évaluer la fidélité, c’est-à-dire évaluer le degré avec lequel le plan a été mis en place comme prévu. Cette thèse avait pour objectif principal de développer des instruments adaptés au contexte francophone québécois afin d’évaluer la fidélité de la RAI. Une méthode mixte a été utilisée selon quatre phases : (1) une étude de délimitation pour développer un cadre conceptuel intégratif de la fidélité, (2) une recension des écrits scientifiques pour déterminer le contenu potentiel des instruments, (3) des rencontres de groupes pour décider du contenu essentiel et pertinent au contexte et (4) des entrevues cognitives afin de prétester les instruments. L’étude de délimitation a inclus 76 documents sur lesquels repose un cadre conceptuel intégratif de la fidélité comprenant deux niveaux et dix dimensions. La recension des écrits a permis de synthétiser 167 articles fournissant les éléments potentiels pour le contenu des instruments de mesure de la fidélité de la RAI. Un total de 50 participants ont pris part à des rencontres de groupes permettant de réduire le nombre d’éléments de plus de la moitié afin de ne garder que le contenu pertinent et essentiel, ainsi que d’obtenir des preuves de la validité de contenu. Des entrevues cognitives avec 35 participants ont permis de prétester les instruments et d’obtenir des preuves de la validité du processus de réponse. Cette thèse a permis le développement d’instruments qui serviront à offrir de la rétroaction sur l’implantation de la RAI dans les écoles francophones québécoises, permettant par le fait même d’améliorer cette implantation. Ces instruments pourront aussi être utilisés pour évaluer la fidélité afin d’éventuellement mener des études d’efficacité.

Doctor of Philosophy(PhD) / Biomedical materials are being extensively researched, and many different types such as metals, metal alloys, and polymers are being used. Currently used biomedical materials are not perfect in terms of corrosion resistance, biocompatibility, and surface properties. It is not easy to fabricate from scratch new materials that can fulfill all requirements and an alternative approach is to modify the surface properties of current materials to cater to the requirements. Plasma immersion ion implantation (PIII) is an effective and economical surface treatment technique and that can be used to enhance the surface properties of biomaterials. The unique advantage of plasma modification is that the surface properties and functionalities can be enhanced selectively while the favorable bulk attributes of the materials such as strength remain unchanged. In addition, the non-line of sight feature of PIII is appropriate for biomedical devices with complex geometries such as orthopedic implants. However, care must be exercised during the plasma treatment because low-temperature treatment is necessary for heat-sensitive materials such as polymers which typically have a low melting point and glass transition temperature. Two kinds of biomedical materials will be discussed in this thesis. One is nickel titanium (NiTi) alloy which is a promising orthopedic implant material due to its unique shape memory and superelastic properties. However, harmful ions may diffuse from the surface causing safety hazards. In this study, we investigate the properties and performance of NiTi after nitrogen and oxygen PIII in terms of the chemical composition, corrosion resistance, and biocompatibility. The XPS results show that barrier layers mainly containing TiN and TiOx are produced after nitrogen and oxygen PIII, respectively. Based on the simulated in vitro and electrochemical corrosion tests, greatly reduced ion leaching and improved corrosion resistance are accomplished by PIII. Porous NiTi is also studied because the porous structure possesses better bone ingrowth capability and compatible elastic modulus with human bones. These advantages promote better recovery in patients. However, higher risks of Ni leaching are expected due to the increased exposed surface area and rougher topography than dense and smooth finished NiTi. We successfully apply PIII to porous NiTi and in vitro tests confirm good cytocompatibility of the materials. The other type of biomedical materials studied here is ultra-high molecular weight polyethylene (UHMWPE) which is a potential material for use in immunoassay plates and biosensors. In these applications, active antibodies or enzymes attached to a surface to detect molecules of interests by means of specific interactions are required. Moreover, the retention of enzyme activity is crucial in these applications. Therefore, the aim of this study is to investigate the use of PIII to prepare UHMWPE surfaces for binding of active proteins in terms of the binding density and ‘shelf life’ of the treated surfaces. Argon and nitrogen PIII treatments are attempted to modify the surface of UHMWPE. Horseradish peroxidase (HRP) is selected to conduct the protein binding test since it is a convenient protein to assay. Experimental results show that both PIII treated surfaces significantly improve the density of active HRP bound to the surface after incubation in buffer containing HRP. Furthermore, the PIII treated surfaces are found to perform better than a commercially available protein binding surface and the shelf life of the PIII treated surfaces under ambient conditions is at least six months. In conclusion, a biocompatible barrier layer on NiTi and a protein binding surface on UHMWPE is synthesized by PIII. The surface properties such as corrosion resistance and functionality on these two different types of substrates are improved by PIII.

Gold (Au) implantation in silicon (Si) has been a topic of great interest from both fundamental and applied perspectives. Ion implantation is a versatile technique due to its ability to form surface-embedded nanoparticles that provide better adhesion. Also, being an integral part of the substrate lattice, the nanoclusters produced by ion implantation are free from impurities and their size distribution can be controlled by carefully optimizing the beam parameters. During our experiments to produce nanoclusters of Au on Si for use as seeds for the growth of nanowires, we stumbled across an unusual pattern formation process under specific conditions. This unique self-assembly process is observed only within a critical threshold implantation fluence and above a threshold annealing temperature. Fabrication of ordered arrays of metal nanoparticles on Si substrates is of significance for both fundamental science associated with low-dimensional physics and technical app lications. The application of functional nanostructures strongly depends on their assembly in ordered one- or two- dimensional arrangements. These arrangements may play an important role in fabricating ordered arrays of semiconductor/oxide nanowires.This thesis discusses a systematic study performed to understand the temperature and time dependent nucleation, growth of Au nanoclusters and evolution of the self-assembled patterns. A growth model is proposed to show the re-crystallization behaviour of Au supersaturated amorphous silicon (a-Si) on Si substrate. The observed self-assembled periodic patterns of Au nanoclusters bear resemblance to the Liesegang ring structures prevalent in some chemical reaction-diffusion systems. Based on this systematic study of the growth and morphology of Au nanoclusters, a tentative growth mechanism has been proposed for the formation mechanism of this unusual self-assembled pattern. The pattern formation of this non-equilibrium process is expected to originate due to instabilities of the three scales of Au nanoclusters at elevated temperatures. The kinetics of pattern formation from a supersaturated solid solution (a-Si/Au alloy) is demonstrated using numerical solutions obtained by a two-dimensional growth model, which takes into account the nucleation, diffusion and the aggregation process. The numerical solution of the diffusion equations appear to be in good agreement with the experimental results.

Wurtzite GaN epilayers grown by metal organic chemical vapor deposition on sapphire substrates were subsequently ion implanted with Er to a dose of 5×10¹⁵ cm⁻². The implanted samples were annealed in nitrogen atmosphere at different temperatures to facilitate recovery from implantation related damage. In this paper we report the annealing behavior of Erbium implanted GaN by using micro Raman spectroscopy and optimized annealing condition. We have observed almost full damage recovery of the crystalline quality of Er implanted GaN after annealing at 1000°C for 2 minute. This observation is further confirmed by using AFM images. / Singapore-MIT Alliance (SMA)

Reproduction de : Thèse doctorat : Informatique : Lyon 2 : 2006. / Titre provenant de l'écran-titre. Bibliogr.