Download or read book Effects of Solution Precursor Nature on Sol gel Derived PZT Thin Film Crystallization Behavior and Properties written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Preparation and Properties of Sol gel Derived PZT Thin Films for Decoupling Capacitor Applications written by and published by . This book was released on 1993 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of ceramic thin films as decoupling capacitors offers the possibility of capacitor integration within the integrated circuit (IC) package, and potentially, directly onto the IC itself. Since these configurations minimize series inductance, higher operational speeds are possible. In the present study we have investigated the dielectric and leakage characteristics of sol-gel PZT films. For compositions near the morphotropic phase boundary, dielectric constants of 1000, and loss tangents of about 0.02, were observed. The current - voltage behavior of the capacitors was characterized by a non-linear response, and significant asymmetry in both the leakage and breakdown characteristics as a function of bias sign was observed. Breakdown fields for PZT 53/47 thin films were typically (approximately)800 kV/cm at 25°C. We have also studied the effects of La and Nb dopant additions and alternate firing strategies on film leakage characteristics. Donor doping at 2 - 5 mol % lowered leakage currents by a factor of 103. For films prepared by a multilayering approach, firing each layer to crystallization resulted in leakage currents that were a factor of 102 lower than films prepared by the standard process.
Download or read book Sol Gel Processing and Applications written by Y.A. Attia and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: During my professional career, I developed a strong interest in sol-gel technology, and worked on both xerogel and aerogel systems. My fascination with aerogels has driven me to explore their commercial potential, which is currently an important component of my company's business plan. Together with my co-workers, I have also worked on the preparation of controlled PZT and silica xerogels as well as thin film coatings of metals by the sol-gel technology, These experiences convinced me of the tremendous potentials of this technology. A conviction that is shared by many scientists, engineers, and business leaders around the globe. Many sol-gel derived products are already articles of commerce. However, to expand the commercial potential of sol-gel technology, two challenges must be met: (1) the quality of sol-gel derived products must continue to meet or exceed the quality of competing products, (2) the production cost of sol-gel products (specially aerogels) must continued to decline. A key to lowering the costs of sol-gel products is finding inexpensive precursors.
Download or read book Densification and Crystallization of Zirconia Thin Films Prepared by Sol gel Processing written by and published by . This book was released on 1993 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have investigated the effects of precursor nature and heat treatment schedule on the densification and crystallization behavior of sol-gel derived zirconia thin films. Precursor solutions were prepared from n-propanol, zirconium (IV) n-propoxide, and either acetic acid, or 2,4-pentanedione (acac) and water additions. By controlling the ligand type and ligand-to-metal ratio, we were able to prepare films which displayed significant differences in densification behavior. We attribute the dissimilarity in densification to variations in the nature of the as-deposited films, as influenced by ligand type and concentration. While the acac- derived film was a physical gel, (i.e., a physical aggregation of the oligomeric species), the acetic acid-derived film, which exhibited less consolidation, was a chemical gel that could not be redissolved in the parent solvent. Films prepared with large acac/metal ratios and small water additions exhibited minimal crosslinking at 25°C, displayed the greatest consolidation ((approximately)86% shrinkage) and the highest refractive index (n = 2.071) when heat treated. These results indicate the importance that M-O-M bonds (crosslinks) formed at low temperature can have on densification behavior. We also report on the effects of heat-treatment schedules and ramp rates on densification behavior. All of the films of the present study crystallized into the cubic phase, at temperatures ranging from (approximately)400°C to greater than 700°C, depending on the heating rate.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemical Solution Deposition of Functional Oxide Thin Films written by Theodor Schneller and published by Springer Science & Business Media. This book was released on 2014-01-24 with total page 801 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first text to cover all aspects of solution processed functional oxide thin-films. Chemical Solution Deposition (CSD) comprises all solution based thin- film deposition techniques, which involve chemical reactions of precursors during the formation of the oxide films, i. e. sol-gel type routes, metallo-organic decomposition routes, hybrid routes, etc. While the development of sol-gel type processes for optical coatings on glass by silicon dioxide and titanium dioxide dates from the mid-20th century, the first CSD derived electronic oxide thin films, such as lead zirconate titanate, were prepared in the 1980’s. Since then CSD has emerged as a highly flexible and cost-effective technique for the fabrication of a very wide variety of functional oxide thin films. Application areas include, for example, integrated dielectric capacitors, ferroelectric random access memories, pyroelectric infrared detectors, piezoelectric micro-electromechanical systems, antireflective coatings, optical filters, conducting-, transparent conducting-, and superconducting layers, luminescent coatings, gas sensors, thin film solid-oxide fuel cells, and photoelectrocatalytic solar cells. In the appendix detailed “cooking recipes” for selected material systems are offered.
Download or read book Sol gel Processing Microstructural Development and Electrical Properties of Ferroelectric Lead Zirconate titanate Thin Films written by Cheng-Chen Hsueh and published by . This book was released on 1991 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Control of Thin Film Processing Behavior Through Precursor Structural Modifications written by and published by . This book was released on 1995 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the sol-gel processing of ceramic thin films it has been frequently noted that the processing behavior, microstructure and properties of the films are dependent on the nature of the coating solution. In an attempt to understand such thin film processing-property relationships, the authors have systematically investigated the effects of varying the precursor nature on thin film densification and crystallization for ZrO2 and TiO2 films. Metal alkoxide starting compounds, e.g., zirconium n-butoxide·n-butanol and titanium i-propoxide, were reacted with acetic acid and 2,4-pentanedione to prepare coating solutions for thin film deposition. The use of these chelating ligands resulted in solution oligomeric species of different nature. Studies of thin film processing indicated that film processing characteristics, i.e., consolidation, densification and crystallization, were strongly dependent on solution precursor nature. Ligand steric size, pyrolysis behavior, extent of chelation, and precursor reactivity were found to be key variables in controlling film processing characteristics.
Download or read book Sol Gel Science written by C. Jeffrey Brinker and published by Academic Press. This book was released on 2013-10-22 with total page 925 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sol-Gel Science: The Physics and Chemistry of Sol-Gel Processing presents the physical and chemical principles of the sol-gel process. The book emphasizes the science behind sol-gel processing with a chapter devoted to applications. The first chapter introduces basic terminology, provides a brief historical sketch, and identifies some excellent texts for background reading. Chapters 2 and 3 discuss the mechanisms of hydrolysis and condensation for nonsilicate and silicate systems. Chapter 4 deals with stabilization and gelation of sols. Chapter 5 reviews theories of gelation and examines the predicted and observed changes in the properties of a sol in the vicinity of the gel point. Chapter 6 describes the changes in structure and properties that occur during aging of a gel in its pore liquor (or some other liquid). The discussion of drying is divided into two parts, with the theory concentrated in Chapter 7 and the phenomenology in Chapter 8. The structure of dried gels is explored in Chapter 9. Chapter 10 shows the possibility of using the gel as a substrate for chemical reactions or of modifying the bulk composition of the resulting ceramic by performing a surface reaction (such as nitridation) on the gel. Chapter 11 reviews the theory and practice of sintering, describing the mechanisms that govern densification of amorphous and crystalline materials, and showing the advantages of avoiding crystallization before sintering is complete. The properties of gel-derived and conventional ceramics are discussed in Chapter 12. The preparation of films is such an important aspect of sol-gel technology that the fundamentals of film formation are treated at length in Chapter 13. Films and other applications are briefly reviewed in Chapter 14. Materials scientists and researchers in the field of sol-gel processing will find the book invaluable.
Download or read book Ceramic Abstracts written by American Ceramic Society and published by . This book was released on 1996 with total page 1000 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal Processing and the Evolution of Composition Structure and Properties for Sol gel Derived Lead Zirconate Titanate Thin Layers written by Charles David Edward Lakeman and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Research is reported for the relationships that exist between processing, composition and structure development, and properties, for sol-gel derived $rm Pb(Zrsb{0.53}Tisb{0.47})Osb3$ (PZT) thin layers. Emphasis was placed on the effect of thermal processing conditions on the gel-to-ceramic conversion. In addition, the effects of interfacial reactions, and residual stresses on the measured properties were also considered. The purpose of the work was to contribute to the fundamental understanding of processes which occur during the high temperature treatment of sol-gel derived thin layers. The gel-to-ceramic conversion was monitored by transmission electron microscopy, diffuse reflectance infrared spectroscopy, and X-ray diffraction. As-deposited coatings were found to be amorphous with compositional heterogeneity at the nanoscale. This is the first report which identifies the nature of the compositional heterogeneity. Structural rearrangement occurred during thermal processing and, for slow heating (50$spcirc$C/min), the coatings approached compositional uniformity on crystallization into the perovskite phase. However, for faster heating rates, the degree of structural rearrangement was limited, thereby decreasing the shrinkage normal to the coating, and crystallization was shifted to a higher temperature. Also, for very rapid thermal processing (5000$spcirc$C/min), compositional heterogeneity was retained in the coatings after crystallization. An apparent dependence on thickness for the properties for ferroelectric PZT thin layers was observed. It was confirmed that a cover coat of a PbO-precursor deposited onto the gel-derived layers prior to firing compensated for the volatilization of PbO which occurred during heating, resulting in coatings which displayed improved properties over those prepared without a cover coat. A simple series capacitor model was investigated to interpret the data. SIMS and TEM analyses indicated that diffusion of some of the species resulted in the formation of a sub-electrode nano-crystalline phase, however, no second phases were observed between the electrode and the coating. Measurements of the residual stress state in PZT coatings deposited onto platinized silicon substrates, and fired at 700$spcirc$C, indicated a tensile stress of approximately +200MPa in the plans of the coating. Thermal expansion mismatch stresses were calculated to be of the order of $-$300MPa in compression, indicating that large tensile stresses were generated during constrained shrinkage.
Download or read book Effects of Acetylacetone Additions on PZT Thin Film Processing written by and published by . This book was released on 1995 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sol-gel processing methods are frequently used for the fabrication of lead zirconate titanate (PZT) thin films for many electronic applications. Our standard approach for film fabrication utilizes lead acetate and acetic acid modified metal alkoxides of zirconium and titanium in the preparation of our precursor solutions. This report highlights some of our recent results on the effects of the addition of a second chelating ligand, acetylacetone, to this process. The authors discuss the changes in film drying behavior, densification and ceramic microstructure which accompany acetylacetone additions to the precursor solution and relate the observed variations in processing behavior to differences in chemical precursor structure induced by the acetylacetone ligand. Improvements in thin film microstructure, ferroelectric and optical properties are observed when acetylacetone is added to the precursor solution.
Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 1948 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sol Gel Technologies for Glass Producers and Users written by Michel Andre Aegerter and published by Springer Science & Business Media. This book was released on 2013-03-19 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sol-Gel Techniques for Glass Producers and Users provides technological information, descriptions and characterizations of prototypes, or products already on the market, and illustrates advantages and disadvantages of the sol-gel process in comparison to other methods. The first chapter entitled "Wet Chemical Technology" gives a summary of the basic principles of the sol-gel chemistry. The most promising applications are related to coatings. Chapter 2 describes the various "Wet Chemical Coating Technologies" from glass cleaning to many deposition and post-coating treatment techniques. These include patterning of coatings through direct or indirect techniques which have became very important and for which the sol-gel processing is particularly well adapted. Chapter 3 entitled "Bulk Glass Technologies" reports on the preparation of special glasses for different applications. Chapter 4 entitled "Coatings and Materials Properties" describes the properties of the different coatings and the sol-gel materials, fibers and powders. The chapter also includes a section dedicated to the characterization techniques especially applied to sol-gel coatings and products.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1996 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sol Gel Spin Coating Growth Of Gallium Nitride Thin Films A Simple Safe and Cheap Approach Penerbit USM written by Fong Chee Yong and published by Penerbit USM. This book was released on 2019 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wide direct band gap gallium nitride (GaN) semiconductor has received significant attention as an ideal material for various applications in the optoelectronic devices. One major use of GaN is the development of energy-efficient solid state light-emitting diodes. Currently, most commercially available GaN semiconductor are produced through advanced deposition techniques which involve sophisticated technologies and are relatively expensive and complicated to setup. As an alternative, the sol-gel spin coating method, which is relatively simpler, cheaper, safer, and more scalable was proposed. In this book, the process route and recipe for producing highly c-oriented crystalline GaN thin films via the sol-gel spin coating approach were described in detail. Some insights into the factors affecting the surface morphology as well as structural and optical properties of the deposited films were presented. Eventually, this book could inspire further studies into the development of low-cost GaN thin films.
Download or read book Sol Gel Derived PZT PLZT and PNZT Thin Films written by Parag Banerjee and published by . This book was released on 2000 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
