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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Preparation and characterization of titanium silicide by MEVVA implantation.

January 1999 (has links)
by Lai Kwong-Yu. / Thesis submitted in: December 1998. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 90-101). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Metal Silicides --- p.1 / Chapter 1.2 --- Titanium Silicide --- p.8 / Chapter 1.3 --- Goal Of This Project --- p.10 / Chapter 2 --- Sample Preparation And Experimental Methods --- p.12 / Chapter 2.1 --- MEVVA Implantation --- p.12 / Chapter 2.2 --- Sample Preparation --- p.15 / Chapter 2.2.1 --- Implantation Condition --- p.15 / Chapter 2.2.2 --- Thermal Treatment --- p.19 / Chapter 2.3 --- Characterization Methods --- p.20 / Chapter 2.3.1 --- Sheet Resistivity Measurement --- p.22 / Chapter 2.3.2 --- X-Ray Diffraction (XRD) --- p.25 / Chapter 2.3.3 --- Rutherford Backscattering Spectroscopy (RBS) --- p.28 / Chapter 2.3.4 --- Transmission Electron Microscopy (TEM) --- p.31 / Chapter 3 --- Characterization of As-implanted Samples --- p.36 / Chapter 3.1 --- Introduction --- p.36 / Chapter 3.2 --- Dose Dependence Of As-implanted Samples --- p.37 / Chapter 3.2.1 --- Sheet Resistance Measurement --- p.37 / Chapter 3.2.2 --- X-Ray Diffraction (XRD) --- p.40 / Chapter 3.2.3 --- Rutherford Backscattering Spectroscopy (RBS) --- p.40 / Chapter 3.3 --- Implant Beam Current Dependence Of As-implanted Samples --- p.43 / Chapter 3.3.1 --- Sheet Resistance Measurement --- p.43 / Chapter 3.3.2 --- X-Ray Diffraction (XRD) --- p.44 / Chapter 3.3.3 --- Rutherford Backscattering Spectroscopy (RBS) --- p.46 / Chapter 3.4 --- Transmission Electron Microscopy (TEM) --- p.48 / Chapter 3.5 --- Summary --- p.52 / Chapter 4 --- Characterization of Annealed Samples --- p.57 / Chapter 4.1 --- Introduction --- p.57 / Chapter 4.2 --- Dose Dependence Of Annealed Samples --- p.58 / Chapter 4.2.1 --- Sheet Resistance Measurements --- p.58 / Chapter 4.2.2 --- X-Ray Diffraction (XRD) --- p.61 / Chapter 4.2.3 --- Rutherford Backscattering Spectroscopy (RBS) --- p.63 / Chapter 4.3 --- Implant Beam Current Dependence Of Annealed Samples --- p.66 / Chapter 4.3.1 --- Sheet Resistance Measurement --- p.66 / Chapter 4.3.2 --- X-Ray Diffraction (XRD) --- p.68 / Chapter 4.3.3 --- Rutherford Backscattering Spectroscopy (RBS) --- p.70 / Chapter 4.4 --- Annealing Temperature Dependence Of Annealed Samples --- p.71 / Chapter 4.4.1 --- Sheet Resistance Measurement --- p.71 / Chapter 4.4.2 --- X-Ray Diffraction (XRD) --- p.73 / Chapter 4.4.3 --- Rutherford Backscattering Spectroscopy (RBS) --- p.75 / Chapter 4.5 --- Annealing Time Dependence Of Annealed Samples --- p.78 / Chapter 4.5.1 --- Sheet Resistance Measurement --- p.78 / Chapter 4.5.2 --- X-Ray Diffraction (XRD) --- p.79 / Chapter 4.5.3 --- Rutherford Backscattering Spectroscopy (RBS) --- p.81 / Chapter 4.6 --- Transmission Electron Microscopy (TEM) --- p.82 / Chapter 4.7 --- Summary --- p.84 / Chapter 5 --- Conclusion --- p.87 / Chapter 5.1 --- Main Results Of This Work --- p.87 / Chapter 5.2 --- Suggestions To Future Works --- p.89 / Bibliography
62

study of MEVVA-implanted copper and nickel in fused silica =: 通過金屬蒸氣眞空弧放電子源把銅和鎳注入熔融石英的硏究. / 通過金屬蒸氣眞空弧放電子源把銅和鎳注入熔融石英的硏究 / A study of MEVVA-implanted copper and nickel in fused silica =: Tong guo jin shu zheng qi zhen kong hu fang dian zi yuan ba tong he nie zhu ru rong rong shi ying de yan jiu. / Tong guo jin shu zheng qi zhen kong hu fang dian zi yuan ba tong he nie zhu ru rong rong shi ying de yan jiu

January 2000 (has links)
by Kong Lim Pun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / by Kong Lim Pun. / ABSTRACT --- p.i / 摘要 --- p.iii / ACNOWLEDGEMENT --- p.iv / TALE OF CONTENTS --- p.v / LIST OF FIGURES --- p.ix / LIST OF TABLES --- p.xi / Chapter CHAPTER 1 --- Introduction / Chapter 1.1 --- Nanoparticles and nanostructural materials --- p.1 / Chapter 1.2 --- Materials of copper-implanted and nickel-implanted fused silica --- p.4 / Chapter 1.2.1 --- Overview --- p.4 / Chapter 1.2.2 --- Formation of nanoparticles --- p.5 / Chapter 1.2.3 --- Optical properties of the material --- p.9 / Chapter 1.3 --- Goals of the project --- p.12 / Reference --- p.13 / Chapter CHAPTER 2 --- Background of Study / Chapter 2.1 --- Introduction --- p.15 / Chapter 2.2 --- Optical absorption of metal nanocluster composite glasses --- p.16 / Chapter 2.2.1 --- Dielectric constant --- p.16 / Chapter 2.2.2 --- The features of surface plasmon resonance peak --- p.16 / Chapter 2.3 --- Third-order optical nonlinearity of metal nanocluster composite glasses --- p.17 / Chapter 2.3.1 --- Classical field confinement --- p.19 / Chapter 2.3.2 --- Quantum confinement --- p.21 / Chapter 2.3.2.1 --- Intraband transitions --- p.21 / Chapter 2.3.2.2 --- Interband transitions --- p.22 / Chapter 2.3.2.3 --- Hot-electron transitions --- p.22 / Chapter 2.4 --- Preparation Methods of MNCG(s) --- p.23 / Chapter 2.4.1 --- Ion implantation --- p.23 / Chapter 2.4.2 --- Ion exchange --- p.23 / Chapter 2.4.3 --- Sputtering deposition --- p.24 / Chapter 2.4.4 --- Melt -quenching and heat-treatment processes --- p.25 / Chapter 2.4.5 --- Ion-beam assisted deposition --- p.25 / Chapter 2.5 --- Applications --- p.25 / Reference --- p.27 / Chapter CHAPTER 3 --- Instrumentation / Chapter 3.1 --- Introduction --- p.29 / Chapter 3.2 --- Metal Vapour Vacuum Arc (MEVVA) ion source implantation --- p.29 / Chapter 3.2.1 --- Background of MEVVA ion source --- p.29 / Chapter 3.2.2 --- Characteristics of MEVVA ion source --- p.32 / Chapter 3.2.3 --- Implantation conditions --- p.33 / Chapter 3.3 --- X-ray photoelectron spectroscopy --- p.34 / Chapter 3.3.1 --- Theory --- p.34 / Chapter 3.3.2 --- Qualitative analysis --- p.38 / Chapter 3.3.2.1 --- Chemical shift peaks --- p.40 / Chapter 3.3.2.2 --- Auger peaks --- p.40 / Chapter 3.3.2.3 --- Energy loss peaks --- p.40 / Chapter 3.3.3 --- Quantitative analysis --- p.41 / Chapter 3.3.3.1 --- Homogeneous system --- p.41 / Chapter 3.3.3.2 --- Determination of layer thickness --- p.45 / Chapter 3.3.4 --- Instrumental components of XPS --- p.47 / Chapter 3.3.4.1 --- Sample introduction system --- p.47 / Chapter 3.3.4.2 --- X-ray source --- p.49 / Chapter 3.3.5 --- Application to metal nanoclusters composite glasses --- p.49 / Chapter 3.3.5.1 --- Compositional analysis --- p.50 / Chapter 3.3.5.2 --- Depth profiling --- p.50 / Chapter 3.3.5.3 --- Auger parameter --- p.50 / Chapter 3.4 --- Transmission electron microscopy --- p.53 / Chapter 3.4.1 --- Basic instrumentation of TEM --- p.53 / Chapter 3.4.2 --- Preparation of TEM cross section specimen --- p.54 / Chapter 3.4.2.1 --- Cutting --- p.54 / Chapter 3.4.2.2 --- "Disc-cutting, grinding, dimpling " --- p.54 / Chapter 3.4.2.3 --- Ion beam thinning --- p.56 / Chapter 3.4.3 --- Image contrast of TEM --- p.56 / Chapter 3.4.4 --- Basic operations of TEM --- p.57 / Chapter 3.4.4.1 --- Bright field and dark field images --- p.57 / Chapter 3.4.4.2 --- Selected area diffraction (SAD) --- p.58 / Chapter 3.4.4.3 --- Convergent Beam Electron Diffraction --- p.59 / Reference --- p.60 / Chapter CHAPTER 4 --- Composition and Nano structure of Copper-implanted Fused Silica / Chapter 4.1 --- Introduction --- p.62 / Chapter 4.2 --- The Atomic Distribution and Chemical State of Copper Nanocluster --- p.64 / Chapter 4.3 --- TEM Studies of Copper Nanoclusters --- p.70 / Chapter 4.4 --- Theoretical Calculation on Ratio of Surface to Bulk Atoms of Copper Nanocluster --- p.73 / Chapter 4.5 --- Conclusions --- p.74 / Reference --- p.77 / Chapter CHAPTER 5 --- Composition and Nanostructure of Nickel-implanted Fused Silica / Chapter 5.1 --- Introduction --- p.79 / Chapter 5.2 --- The distribution of nickel nanoclusters --- p.80 / Chapter 5.3 --- TEM studies of nickel nanoclusters --- p.81 / Chapter 5.4 --- Chemical state of nickel clusters --- p.87 / Chapter 5.5 --- Discussion --- p.90 / Chapter 5.6 --- Conclusion --- p.90 / Reference --- p.92 / Chapter CHAPTER 6 --- Conclusions --- p.94
63

Formation and characterization of FeSi2 thin films and precipitates prepared by metal vapor vacuum arc (MEVVA) ion implanation. / CUHK electronic theses & dissertations collection

January 2002 (has links)
by Gao Yun. / "November 2002." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (p. 165-171). / 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.
64

Characterization of magnetic nanocomposite thin films for high density recording prepared by pulsed filtered vacuum arc deposition. / CUHK electronic theses & dissertations collection

January 2004 (has links)
by Chiah Man Fat. / "March 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references. / 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.
65

Routes to control the crystal structure, morphology and aligned growth of quasi-one-dimensional Zn-Cd-Se nanostructures by metalorganic chemical vapor deposition. / 通過金屬有機物化學氣相沉積法合成晶體結構, 形貌及生長取向性可控的硒鋅鎘族准一維納米結構 / CUHK electronic theses & dissertations collection / Routes to control the crystal structure, morphology and aligned growth of quasi-one-dimensional Zn-Cd-Se nanostructures by metalorganic chemical vapor deposition. / Tong guo jin shu you ji wu hua xue qi xiang chen ji fa he cheng jing ti jie gou, xing mao ji sheng chang qu xiang xing ke kong de xi xin ge zu zhun yi wei na mi jie gou

January 2007 (has links)
Studying quasi-one-dimensional (1D) semiconductor nanostructures is an attractive and active research field in nanoscience and nanotechnology. Their controllable growth is the foundation for observing novel properties and fabricating useful nano-devices and is also a challenge. / We believe that our work in perfecting the fabrication of aligned 1D semiconductor nanostructures and control of their morphology, crystal structure and orientation will shed more light on the understanding on 1D physics and advancement in nanotechnology. / We have studied the control of the structure, morphology and alignment of Zn-Cd-Se 1D nanostructures by fine tuning their growth conditions and judiciously choosing substrates in a metalorganic chemical vapor deposition (MOCVD) reactor. We found that the products are zincblende structured nanoneedles at relatively low temperatures and pressures, and wurtzite structured nanowires at high temperatures and pressures. We have fabricated aligned 1D nanostructures of different chemical compositions by exploiting the epitaxial relationship between the lattices of Zn-Cd-Se system and GaAs substrate. From the systematic studies of the orientations of the aligned samples, we demonstrated that they can be controlled by the crystallographic surface of the substrate. We also found that the orientation can be affected by the growth temperature. Three growth models are suggested to explain the aligned growth for zincblende and wurtzite 1D nanostructures and complex shaped three-bladed nanoswords. Observations and angular measurements of the orientations and growth directions by electron microscopy and analyses by pole stereographs offer supporting evidences for the models. Polarized photoluminescence studies of individual CdSe nanowires obtained under controlled growth have been achieved. / Liu, Zhuang = 通過金屬有機物化學氣相沉積法合成晶體結構, 形貌及生長取向性可控的硒鋅鎘族准一維納米結構 / 劉壯. / "July 2007." / Adviser: Sui Kong Hark. / Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 1062. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307. / Liu, Zhuang = Tong guo jin shu you ji wu hua xue qi xiang chen ji fa he cheng jing ti jie gou, xing mao ji sheng chang qu xiang xing ke kong de xi xin ge zu zhun yi wei na mi jie gou / Liu Zhuang.
66

Novel fabrication processes for thin film vapour deposited strain gauges on mild steel

Djugum, Richard, n/a January 2006 (has links)
Pressure measurement using a strain gauge bonded with epoxy adhesive to a metallic mechanical support has been, and still is, extensively employed, however, for some applications the use of an epoxy is inadequate, especially when temperatures exceed 120C. There is therefore particular interest in the use of thin film techniques to vacuum deposit strain gauges directly on metallic substrates. Such devices are highly cost effective when produced in large quantities due to the manufacturing techniques involved. This makes them ideally suited for use in large-volume products such as electronic weighing scales and pressure transducers. In this thesis, new techniques for fabricating thin film vapour deposited strain gauge transducers on metal substrates for application as novel pressure sensors in the fastener industry are developed. Clearly, for a vapour deposited strain gauge to function correctly, it is essential that it be deposited on a defect free, high quality electrically insulating film. This was a significant challenge in the present study since all available physical vapour deposition (PVD) equipment was direct current (DC) and insulators of around 4 um thick were needed to electrically isolate the strain gauges from metal. As a result, several methods of depositing insulators using DC were developed. The first involved the use of DC magnetron sputtering from an aluminium target to reactively deposit up to 4 um thick AlN. DC magnetron discharges suffer arc instability as the AlN forms on the target and this limits the maximum thickness that can be deposited. Consequently, the arc instability was suppressed manually by increasing argon gas flow at the onset of arcing. Although the deposited AlN showed a high insulating resistance, it was found that the breakdown voltage could significantly increase by (a) utilising a metallic interlayer between the thin film insulator and the metallic substrate and (b) annealing in air at 300C. A second deposition method involved the use of DC magnetron sputtering to deposit modulated thin film insulators in which an aluminium target was used to reactively deposit alternating layers of aluminium nitride and aluminium oxide. These films showed significant increases in average breakdown voltage when the number of layers within the composite film was increased. The third method involved the deposition of AlN thin film insulators using partially filtered cathodic arc evaporation with shielding. Initially, AlN was deposited under partially filtered conditions to obtain a relatively thick (~ 4 um) coating then, while still depositing under partially filtered conditions, a smooth top coating was deposited by using a shielding technique. The deposition of metal macroparticles is an inherent problem with cathodic arc deposition and shielding is one form of macroparticle filtering. Such particles are highly undesirable in this study as they are electrically conductive. A fourth coating technique for depositing insulators on steel was based on thermal spray technology. Insulating films of Al2O3 were plasma sprayed and then polished to thereby fabricate viable electrical insulators for vapour deposited strain gauges. With respect to depositing strain gauges two methods were employed. The first involved the sputter deposition of chromium through a shadow mask to form a strain gauge with gauge factor sensitivity of around 2. The second used cathodic arc evaporation to fabricate a multi-layered strain gauge composed of alternating CrN and TiAlN layers that yielded a gauge factor of around 3.5. The technique achieves better compatibility between gauge and insulator by allowing a wider selection of materials to form the gauge composition. Finally, a novel pressure sensor in the form of a load cell was developed that consisted of a chromium strain gauge on a steel washer electrically insulated with AlN thin film. The load cell showed good performance when tested under compressive load.
67

An alternative structure for next generation regulatory controllers and scale-up of copper(indium gallium)selenide thin film co-evaporative physical vapor deposition process

Mukati, Kapil. January 2007 (has links)
Thesis (Ph.D.)--University of Delaware, 2007. / Principal faculty advisor: Babatunde Ogunnaike, Dept. of Chemical Engineering, and Robert W. Birkmire, Dept. of Materials Science & Engineering. Includes bibliographical references.
68

Laser Processing of Biological Materials

Patz, Timothy Matthew 14 July 2005 (has links)
I have explored the use of the matrix assisted pulsed laser evaporation (MAPLE) and MAPLE direct write (MDW) to create thin films of biological materials. MAPLE is a novel physical vapor deposition technique used to deposit thin films of organic materials. The MAPLE process involves the laser desorption of a frozen dilute solution (1-5%) containing the material to be deposited. A focused laser pulse (~200 mJ/cm2) impacts the frozen target, which causes the solvent to preferentially absorb the laser energy and evaporate. The collective action of the evaporated solvent desorbs the polymeric solute material towards the receiving substrate placed parallel and opposite to the target. The bioresorbable polymer PDLLA and the anti-inflammatory pharmaceutical dexamethasone were processed using MAPLE, and characterized using Fourier transform infrared spectroscopy, atomic force microscopy and x-ray photoelectron spectroscopy. MDW is a CAD/CAM controlled direct writing process. The material to be transferred is immersed in a laser-absorbing matrix or solution and coated onto a target or support positioned microns to millimeters away from a receiving substrate. Using a UV microscope objective, a focused laser pulse is directed at the backside of the ribbon, so that the laser energy first interacts with the matrix at the ribbon/matrix interface. This energy is used to gently desorb the depositing material and matrix onto the receiving substrate. I have deposited neuroblasts within a three-dimensional extracellular matrix. These two laser processing techniques have enormous potential for functional medical device and tissue engineering applications.
69

Non-contact atomic force microscopy studies of amorphous solid water deposited on Au(111) /

Donev, Jason Matthew Kaiser, January 2003 (has links)
Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 135-138).
70

Design and operation of an advanced laser chemical vapor deposition system with on-line control

Jean, Daniel Louis 08 1900 (has links)
No description available.

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