Download or read book Examining Wetting and Dewetting Processes in Thin films on Crystalline Substrates at the Nanoscale written by Sahar Hihath and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Controlling the wetting and dewetting of ultra-thin films on solid substrates is important for a variety of technological and fundamental research applications. These applications include film deposition for semiconductor manufacturing, the growth of nanowires through nanoparticle-based catalysis sites, to making ordered arrays of nanoscale particles for electronic and optical devices. However, despite the importance of these processes, the underlying mechanisms by which a film wets a surface or dewets from it is still often unclear and widely debated. In this dissertation we examine wetting and dewetting processes in three materials systems that are relevant for device applications with the ultimate goal of understanding what mechanisms drive the wetting (or dewetting) process in each case. First, we examine the formation of wetting layers between nanoparticle films and highly conductive GaAs substrates for spintronic applications. In this case, the formation of a wetting layer is important for nanoparticle adhesion on the substrate surface. Wetting layers can be made by annealing these systems, which causes elemental diffusion from nanoparticles into the substrate, thereby adhesion between the nanoparticles and the substrate. Here we investigate the feasibility of forming a wetting layer underneath nanoparticles post-annealing in a system of Fe3O4 nanoparticles on a (100) GaAs substrate by studying the interface structure and composition via Transmission Electron Microscopy (TEM), Scanning Transmission Electron Microscopy (STEM), Electron Energy Loss Spectroscopy (EELS) and Energy Dispersive X-ray Spectroscopy (EDXS). Electron Energy-Loss fine structures of the Fe-L3,2 and O-K absorption edges were quantitatively analyzed to gain insight about the compositional gradient of the interface between the nanoparticles and the GaAs substrate. Additionally, real-space density functional theory calculations of the dynamical form factor was performed to confirm the experimental observations. Second, the fundamental mechanisms that govern the onset of dewetting of thin metal films in both liquid and solid state are investigated. Dewetting processes are used in numerous technological applications. For instance, the dewetting of thin films on substrates is used for making spatially ordered nanoparticle arrays for use in plasmonics, nanophotonics, and magnetics. [1] In addition to dewetting applications in industry and research, dewetting processes have adverse impact on the reliability of semiconductor devices as it can limit the functionality of metal contacts utilized in transistors at elevated temperatures. The morphological changes during dewetting have been studied previously in plan-view by Scanning Electron Microscopy (SEM) after the annealing is completed, and in some cases in cross-section via real-time Transmission Electron Microscopy (TEM). However, due to temporal limitations of image acquisition in TEM, which is in the range of milliseconds, it has not been possible thus far to investigate the dynamics of the dewetting process with high-speed time resolution from nano- to micro-seconds. To gain insights into the fundamental mechanisms involved in dewetting, the early stages of the dewetting process were investigated via Dynamic Transmission Electron Microscopy (DTEM) with nanosecond time and nanometer spatial resolution. The experiments were performed on plan-view TEM samples consisting of nickel thin-films on (100) silicon substrates with a 2-3 nm thick native oxide. The laser ablation dynamics were captured, which involved liquid phase dewetting of the nickel film followed by substrate fracture and nanoscale particle expulsion. Finally, to capture the full dynamics of the dewetting process the experiments were performed on a system of nickel thin-films on (100) Strontium Titanate (STO) substrates. Samples of nickel thin-films on STO substrates have lower thermal expansion coefficient mismatch compared to the system discussed above. Thus, the STO substrates did not fracture after laser irradiation and enabled us to capture the progress of hole growth with time. Valence Electron Energy Loss spectroscopy was used to find the thickness of the TEM sample in order to calculate the geometry and simulate the temperature fields via finite element analysis with COMSOL Multiphysics package. Spatio-temporal temperature plots acquired from finite element modeling suggests that both liquid and solid-state dewetting processes were observed depending upon the magnitude of the laser energy used.

Download or read book Dewetting and Stress Evolution in Thin Films During Ion Irradiation written by Kai Zhao and published by ProQuest. This book was released on 2008 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project studies the morphology evolution of non-wetting metal films on a substrate during ion irradiation. It reveals that the mobility of the solid atoms is significantly improved during irradiation and the non-wetting films can dewet as if they are melted. The ion induced dewetting process can result into patterned nanoscale structures by self-organization. This project also investigates the stress evolution in thin films when they're bombarded with ∼1keV ions. Processes such as vacancy creation and phase transformation play important roles in the stress accumulation of the films. Meanwhile, it is discovered that atoms can be injected into deeper region from the ion bombarded layer during irradiation, inducing a compressive stress generation process. It is also noticed that despite the variance in their microstructures, the films show many common features in stress development during ion irradiation.

Download or read book Glancing Angle Deposition of Thin Films written by Matthew M. Hawkeye and published by John Wiley & Sons. This book was released on 2014-07-03 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a highly practical treatment of Glancing Angle Deposition (GLAD), a thin film fabrication technology optimized to produce precise nanostructures from a wide range of materials. GLAD provides an elegant method for fabricating arrays of nanoscale helices, chevrons, columns, and other porous thin film architectures using physical vapour deposition processes such as sputtering or evaporation. The book gathers existing procedures, methodologies, and experimental designs into a single, cohesive volume which will be useful both as a ready reference for those in the field and as a definitive guide for those entering it. It covers: Development and description of GLAD techniques for nanostructuring thin films Properties and characterization of nanohelices, nanoposts, and other porous films Design and engineering of optical GLAD films including fabrication and testing, and chiral films Post-deposition processing and integration to optimize film behaviour and structure Deposition systems and requirements for GLAD fabrication A patent survey, extensive relevant literature, and a survey of GLAD's wide range of material properties and diverse applications.

Download or read book Nanoscale Metal Thin Film Dewetting Via Nanosecond Laser Melting written by Yueying Wu and published by . This book was released on 2011 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanoscale metal thin film dewetting via laser treatment is studied in this dissertation. The purpose is to understand: 1) the spatial and temporal nature of intrinsic instabilities; and 2) mass transportation involved in dewetting pattern evolution in metal thin films as well as in lithographically patterned nanostructures; and finally 3) to explore advanced control of metallic nanostructure fabrication via the confluence of top down nanolithography and pulsed laser induced dewetting. This study includes three sections. In first section, thin film Cu-Ni alloys ranging from 2-8nm were synthesized and laser irradiated. The evolution of the spinodal dewetting process is investigated as a function of the thin film composition which ultimately dictates the size distribution and spacing of the nanoparticles, and the optical measurements of the copper rich alloy nanoparticles revealed characteristic plasmonic peaks. In section two, the dewetting behavior of nanolithographically patterned copper rings on Silicon substrate was studied. The self assembly of the rings into ordered nanoparticle/nanodrop arrays was accomplished via nanosecond pulsed laser heating. The resultant length scale of the 13nm and 7nm thick copper rings was correlated to the competition between transport and instabilities time scales during the liquid lifetime of the melted copper rings. To explore the influence of different substrates with different surface energy, the pulsed laser heated assembly of lithographically patterned copper rings on SiO2 substrate was studied in the last section. The correlated transport and instabilities show modified timescales. It is demonstrated again that the original geometry dictates the instability pathway, which for narrow rings obeys the Rayleigh-Plateau instability and for wider rings are influenced by the thin film instability.

Download or read book Wetting Dewetting Transitions of Au Ni Bilayer Films written by Cen, Xi and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin films deposited at low temperatures are often kinetically constrained and will dewet the underlying substrate when annealed. Solid state dewetting is driven by the minimization of the total free energy of thin film-substrate interface and free surface, and mostly occurs through surface diffusion. Dewetting is a serious concern in microelectronics reliability. However, it can also be utilized for the self-assembly of nanostructures with potentials in storage, catalysis, or transistors. Therefore, a fundamental understanding of the dewetting behavior of thin metal films is critical for improving the thermal stability of microelectronics and controlling the order of self-assembled nanostructures. Mechanisms for dewetting of single layer films have been studied extensively. However little work has been reported on multilayer or alloyed thin films. In the thesis, the solid state dewetting of Au/Ni bilayer films deposited on SiO2/Si substrates was investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and aberration corrected scanning TEM (STEM). Ex-situ SEM and TEM studies were performed with in-situ TEM heating characterization to identify the mechanisms during the dewetting process of Au/Ni bilayer films. The solid state dewetting of Au/Ni bilayer films from SiO2/Si substrates exhibits both homogeneous and localized dewetting of Ni and long-edge retraction for Au under isothermal annealing condition. The top Au layer retracts up to 1 mm from the edge of the substrate wafer to reduce the energetically unfavored Au/Ni interface. In contrast, Ni dewets and agglomerates locally due to its limited diffusivity compared to Au. Film morphology and local chemical composition varies significantly across hundreds of microns along the direction normal to the retracting edge. Besides long range edge receding, localized dewetting shows significant changes in film morphology and chemical distribution. Both Au and Ni shows texturing. Despite the initial deposition sequence of the as-deposited Au/Ni/SiO2/Si interface structure, the majority of the metal/SiO2 interface is Au/SiO2 after annealing at 675°C for 1 hour. Cross-Sectional TEM revealed that void nucleation is predominantly observed at Au/Ni/SiO2 triple junctions, rather than grain boundary grooving at free surface of the metal film. The formation of Au/SiO2 interface sections is found to be energetically preferred over Ni/SiO2 due to compressive stress in the as-deposited Ni layer. In-situ cross-sectional TEM heating studies demonstrate that the dewetting transition initiates at 400°C. Au diffuses through Ni grain boundaries towards the underlying Ni layer and forms more energetically favorable Au/SiO2 interface. The adsorption of Au along Ni grain boundaries, NiO[subscript x]/Ni and SiO2/Ni phase boundaries is observed to lower the interfacial energy. The experimental observations suggest that alloying, unequal self-diffusion coefficient and metal/metal interface strongly affect the bilayer dewetting process.

Download or read book Evolution of Thin Film Morphology written by Matthew Pelliccione and published by Springer Science & Business Media. This book was released on 2008-01-29 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this book is on modeling and simulations used in research on the morphological evolution during film growth. The authors emphasize the detailed mathematical formulation of the problem. The book will enable readers themselves to set up a computational program to investigate specific topics of interest in thin film deposition. It will benefit those working in any discipline that requires an understanding of thin film growth processes.

Download or read book Integration of 2D Materials for Electronics Applications written by Filippo Giannazzo and published by MDPI. This book was released on 2019-02-13 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Integration of 2D Materials for Electronics Applications" that was published in Crystals

Download or read book Nanostructured Surfaces and Thin Films Synthesis by Physical Vapor Deposition written by Rafael Alvarez and published by MDPI. This book was released on 2021-04-22 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Special Issue deals with the synthesis of nanostructured surfaces and thin films by means of physical vapor deposition techniques such as pulsed laser deposition, magnetron sputtering, HiPIMS, or e-beam evaporation, among others. The nanostructuration of the surface modifies the way a material interacts with the environment, changing its optical, mechanical, electrical, tribological, or chemical properties. This can be applied in the development of photovoltaic cells, tribological coatings, optofluidic sensors, or biotechnology to name a few. This issue includes research presenting novel or improved applications of nanostructured thin films, such as photovoltaic solar cells, thin-film transistors, antibacterial coatings or chemical and biological sensors, while also studying the nanostructuration mechanisms, from a fundamental point of view, that produce rods, columns, helixes or hexagonal grids at the nanoscale.

Download or read book Polymer Thin Films written by Ophelia Kwan Chui Tsui and published by World Scientific. This book was released on 2008 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ch. 1. Block copolymer thin films / J.-Y. Wang, S. Park and T. P. Russell -- ch. 2. Equilibration of block copolymer films on chemically patterned surfaces / G. S. W. Craig, H. Kang and P. F. Nealey -- ch. 3. Structure formation and evolution in confined cylinder-forming block copolymers / G. J. A. Sevink and J. G. E. M. Fraaije -- ch. 4. Block copolymer lithography for magnetic device fabrication / J. Y. Cheng and C. A. Ross -- ch. 5. Hierarchical structuring of polymer nanoparticles by self-organization / M. Shimomura ... [et al.] -- ch. 6. Wrinkling polymers for surface structure control and functionality / E. P. Chan and A. J. Crosby -- ch. 7. Crystallization in polymer thin films: morphology and growth / R. M. Van Horn and S. Z. D. Cheng -- ch. 8. Friction at soft polymer surface / M. K. Chaudhury, K. Vorvolakos and D. Malotky -- ch. 9. Relationship between molecular architecture, large-strain mechanical response and adhesive performance of model, block copolymer-based pressure sensitive adhesives / C. Creton and K. R. Shull -- ch. 10. Stability and dewetting of thin liquid films / K. Jacobs, R. Seemann and S. Herminghaus -- ch. 11. Anomalous dynamics of polymer Films / O. K. C. Tsui.

Download or read book Stem Cells Regenerative Medicine written by Krishnarao Appasani and published by Springer Science & Business Media. This book was released on 2010-11-01 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: Defined as, “The science about the development of an embryo from the fertilization of the ovum to the fetus stage,” embryology has been a mainstay at universities throughout the world for many years. Throughout the last century, embryology became overshadowed by experimental-based genetics and cell biology, transforming the field into developmental biology, which replaced embryology in Biology departments in many universities. Major contributions in this young century in the fields of molecular biology, biochemistry and genomics were integrated with both embryology and developmental biology to provide an understanding of the molecular portrait of a “development cell.” That new integrated approach is known as stem-cell biology; it is an understanding of the embryology and development together at the molecular level using engineering, imaging and cell culture principles, and it is at the heart of this seminal book. Stem Cells and Regenerative Medicine: From Molecular Embryology to Tissue Engineering is completely devoted to the basic developmental, cellular and molecular biological aspects of stem cells as well as their clinical applications in tissue engineering and regenerative medicine. It focuses on the basic biology of embryonic and cancer cells plus their key involvement in self-renewal, muscle repair, epigenetic processes, and therapeutic applications. In addition, it covers other key relevant topics such as nuclear reprogramming induced pluripotency and stem cell culture techniques using novel biomaterials. A thorough introduction to stem-cell biology, this reference is aimed at graduate students, post-docs, and professors as well as executives and scientists in biotech and pharmaceutical companies.

Download or read book Nanoscale Science and Technology written by Robert Kelsall and published by John Wiley & Sons. This book was released on 2005-11-01 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanotechnology is a vital new area of research and development addressing the control, modification and fabrication of materials, structures and devices with nanometre precision and the synthesis of such structures into systems of micro- and macroscopic dimensions. Future applications of nanoscale science and technology include motors smaller than the diameter of a human hair and single-celled organisms programmed to fabricate materials with nanometer precision. Miniaturisation has revolutionised the semiconductor industry by making possible inexpensive integrated electronic circuits comprised of devices and wires with sub-micrometer dimensions. These integrated circuits are now ubiquitous, controlling everything from cars to toasters. The next level of miniaturisation, beyond sub-micrometer dimensions into nanoscale dimensions (invisible to the unaided human eye) is a booming area of research and development. This is a very hot area of research with large amounts of venture capital and government funding being invested worldwide, as such Nanoscale Science and Technology has a broad appeal based upon an interdisciplinary approach, covering aspects of physics, chemistry, biology, materials science and electronic engineering. Kelsall et al present a coherent approach to nanoscale sciences, which will be invaluable to graduate level students and researchers and practising engineers and product designers.

Download or read book Solution Processing of Inorganic Materials written by David Mitzi and published by John Wiley & Sons. This book was released on 2008-12-22 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discover the materials set to revolutionize the electronics industry The search for electronic materials that can be cheaply solution-processed into films, while simultaneously providing quality device characteristics, represents a major challenge for materials scientists. Continuous semiconducting thin films with large carrier mobilities are particularly desirable for high-speed microelectronic applications, potentially providing new opportunities for the development of low-cost, large-area, flexible computing devices, displays, sensors, and solar cells. To date, the majority of solution-processing research has focused on molecular and polymeric organic films. In contrast, this book reviews recent achievements in the search for solution-processed inorganic semiconductors and other critical electronic components. These components offer the potential for better performance and more robust thermal and mechanical stability than comparable organic-based systems. Solution Processing of Inorganic Materials covers everything from the more traditional fields of sol-gel processing and chemical bath deposition to the cutting-edge use of nanomaterials in thin-film deposition. In particular, the book focuses on materials and techniques that are compatible with high-throughput, low-cost, and low-temperature deposition processes such as spin coating, dip coating, printing, and stamping. Throughout the text, illustrations and examples of applications are provided to help the reader fully appreciate the concepts and opportunities involved in this exciting field. In addition to presenting the state-of-the-art research, the book offers extensive background material. As a result, any researcher involved or interested in electronic device fabrication can turn to this book to become fully versed in the solution-processed inorganic materials that are set to revolutionize the electronics industry.

Download or read book Physical Foundations of Materials Science written by Günter Gottstein and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 511 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this vivid and comprehensible introduction to materials science, the author expands the modern concepts of metal physics to formulate basic theory applicable to other engineering materials, such as ceramics and polymers. Written for engineering students and working engineers with little previous knowledge of solid-state physics, this textbook enables the reader to study more specialized and fundamental literature of materials science. Dozens of illustrative photographs, many of them transmission electron microscopy images, plus line drawings, aid developing a firm appreciation of this complex topic. Hard-to-grasp terms such as "textures" are lucidly explained - not only the phenomenon itself, but also its consequences for the material properties. This excellent book makes materials science more transparent.

Download or read book Impact of Electron and Scanning Probe Microscopy on Materials Research written by David G. Rickerby and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Advanced Study Institute provided an opportunity for researchers in universities, industry and National and International Laboratories, from the disciplines ofmaterials science, physics, chemistry and engineering to meet together in an assessment of the impact of electron and scanning probe microscopy on advanced material research. Since these researchers have traditionally relied upon different approaches, due to their different scientific background, to advanced materials problem solving, presentations and discussion within the Institute sessions were initially devoted to developing a set ofmutually understood basic concepts, inherently related to different techniques ofcharacterization by microscopy and spectroscopy. Particular importance was placed on Electron Energy Loss Spectroscopy (EELS), Scanning Probe Microscopy (SPM), High Resolution Transmission and Scanning Electron Microscopy (HRTEM, HRSTEM) and Environmental Scanning Electron Microscopy (ESEM). It was recognized that the electronic structure derived directly from EELS analysis as well as from atomic positions in HRTEM or High Angle Annular Dark Field STEM can be used to understand the macroscopic behaviour of materials. The emphasis, however, was upon the analysis of the electronic band structure of grain boundaries, fundamental for the understanding of macroscopic quantities such as strength, cohesion, plasticity, etc.

Download or read book The Properties of Water and Their Role in Colloidal and Biological Systems written by Carel J. Van Oss and published by Academic Press. This book was released on 2008-11-19 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book also treats the surface properties of apolar and polar molecules, polymers, particles and cells, as well as their mutual interaction energies, when immersed in water, under the influence of the three prevailing non-covalent forces, i.e., Lewis acid-base (AB), Lifshitz-van der Waals (LW) and electrical double layer (EL) interactions. The polar AB interactions, be they attractive or repulsive, typically represent up to 90% of the total interaction energies occurring in water. Thus the addition of AB energies to the LW + EL energies of the classical DLVO theory of energy vs. distance analysis makes this powerful tool (the Extended DLVO theory) applicable to the quantitative study of the stability of particle suspensions in water.-

Download or read book Liquid Cell Electron Microscopy written by Frances M. Ross and published by Cambridge University Press. This book was released on 2017 with total page 529 pages. Available in PDF, EPUB and Kindle. Book excerpt: 2.6.2 Electrodes for Electrochemistry

Download or read book Stimuli Responsive Dewetting Wetting Smart Surfaces and Interfaces written by Atsushi Hozumi and published by Springer. This book was released on 2018-11-16 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superhydrophobic surfaces, artificially mimicking lotus leaves, have captured the attention of scientists and engineers over the past few decades. Recent trends have shifted from superhydrophobicity to superominipohobicity, or superamphiphobicity. In addition, dynamic rather than static surface wetting/dewetting properties, which can be triggered by various stimuli, including temperature, pH, magnetic/electric fields, solvents, light exposure etc, have been highly sought after for commercial applications. This book will focus on recent topics related to various stimuli-responsive wetting/dewetting surfaces, and give an overview of the knowledge and concepts of how to design and establish these smart artificial surfaces, which can be used for technical developments in a wide variety research fields.