Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Properties And Characterization Of Amorphous Carbon Films
Download Properties And Characterization Of Amorphous Carbon Films full books in PDF, epub, and Kindle. Read online Properties And Characterization Of Amorphous Carbon Films ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Properties and Characterization of Amorphous Carbon Films by : J.J. Pouch
Download or read book Properties and Characterization of Amorphous Carbon Films written by J.J. Pouch and published by Trans Tech Publications Ltd. This book was released on 1991-01-01 with total page 714 pages. Available in PDF, EPUB and Kindle. Book excerpt: Amorphous, hydrogenated carbon (AHC) films can be deposited on various substrates using several techniques, e.g. plasma deposition and ion beam deposition. The resulting films can be hard, wear resistant and transparent.
Book Synopsis Preparation and Characterization of Hydrogenated Amorphous Carbon Films by : B. Meyerson
Download or read book Preparation and Characterization of Hydrogenated Amorphous Carbon Films written by B. Meyerson and published by . This book was released on 1981 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Synthesis and Characterization of Amorphous Carbon Films for Magnetic Storage Technology by : Jun Xie
Download or read book Synthesis and Characterization of Amorphous Carbon Films for Magnetic Storage Technology written by Jun Xie and published by . This book was released on 2015 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increasing demands for high magnetic storage capacity have led to the increase of the recording area density, mainly by reducing the distance between the magnetic media on the hard disk and the magnetic transducer of the head. A factor that has greatly contributed to the profound decrease of the magnetic spacing is excessive thinning of the protective amorphous carbon (a-C) overcoat. However, the remarkable decrease in overcoat thickness raises a concern about its quality and protective capability. In general, a-C films with higher sp3 carbon atom hybridization demonstrate higher density and better tribomechanical and corrosion properties. The sp2 and sp3 contents strongly depend on the film-growth conditions and deposition method. One of the most common film deposition methods is radio-frequency (RF) sputtering. This method uses low-energy neutral carbon atoms or clusters of atoms as film precursors and has been the workhorse of storage technology for more than four decades. Typically, Ar+ ion bombardment of the growing film during film growth is used to tailor the overcoat structure and properties without affecting its chemical environment. The substrate bias voltage is a key deposition parameter because it directly affects the ion bombardment energy. In this dissertation, the effect of the substrate bias voltage on the growth and properties of ultrathin a-C films was examined and the identified film structure-property interdependencies were explained in the context of an analytical model, which takes into account the effects of irradiation damage and thermal spikes. Substrate biasing during film deposition may lead to some undesirable effects, such as the development of a high compressive residual stress, which can cause premature overcoat failure by delamination. Experimental studies of this dissertation show that alternating between biasing and non-biasing deposition conditions, multi-layer a-C films consisting of ultrathin hard (bias on) and soft (bias off) layers characterized by high sp3 fraction and greatly reduced compressive residual stress can be synthesized by RF sputtering. An additional advantage is that these multi-layer a-C films exhibit lower surface roughness and improved tribological properties. Different from deposition methods using neutral carbon atoms as film-forming precursors, such as RF sputtering and other physical vapor deposition methods, filtered cathodic vacuum arc (FCVA) uses energetic C+ ions as film precursors, which is advantageous for depositing ultrathin and very smooth a-C films with superior nanomechanical/tribological properties. The role of important FCVA process parameters, such as substrate bias voltage, which controls the C+ ion energy, in the film growth process were investigated, while considering various means of reducing the a-C film thickness without jeopardizing its structure and properties. The effect of the duty cycle of substrate pulse biasing (i.e., the ratio of the time of substrate biasing over a pulse to the pulse bias period) was examined in terms of film deposition rate, surface topography, and nanostructure. Cross-sectional high-resolution transmission electron microscopy (HRTEM) combined with the scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) studies revealed variations in through-thickness hybridization and density with duty cycle. a-C films with the highest sp3 content and smallest thickness were synthesized under FCVA deposition conditions of 75% and 65% duty cycle, respectively. EELS studies show that a-C films generally possess a multi-layered structure consisting of surface and interface layers of relatively low sp3 contents and intermediate bulk layer of much higher sp3 content, a result of the deposition mechanisms encountered during ion bombardment. When the a-C film thickness is reduced to only 2-3 nm, the effects of the ultrathin (1-2 nm) surface and interface layers become increasingly more pronounced, resulting in the decrease of the overall sp3 content and, in turn, depletion of the film's protective capability. To reduce the thickness of the interface layer, a thin (
Book Synopsis Characterization of Amorphous Carbon Films Grown by Pulsed-laser Deposition by :
Download or read book Characterization of Amorphous Carbon Films Grown by Pulsed-laser Deposition written by and published by . This book was released on 1998 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Amorphous carbon (a-C) films grow via energetic processes such as pulsed-laser deposition (PLD). The cold-cathode electron emission properties of a-C are promising for flat-panel display and vacuum microelectronics technologies. These ultrahard films consist of a mixture of 3-fold and 4-fold coordinated carbon atoms, resulting in an amorphous material with diamond-like properties. The authors study the structures of a-C films grown at room temperature as a function of PLD energetics using x-ray reflectivity, Raman spectroscopy, high-resolution transmission electron microscopy, and Rutherford backscattering spectrometry. While an understanding of the electron emission mechanism in a-C films remains elusive, the onset of emission is typically preceded by conditioning where the material is stressed by an applied electric field. To simulate conditioning and assess its effect, the authors use the spatially-localized field and current of a scanning tunneling microscope tip. Scanning force microscopy shows that conditioning alters surface morphology and electronic structure. Spatially-resolved electron energy loss spectroscopy indicates that the predominant bonding configuration changes from predominantly 4-fold to 3-fold coordination.
Book Synopsis Optical and Structural Characterization of Amorphous Carbon Films by : Pratish Mahtani
Download or read book Optical and Structural Characterization of Amorphous Carbon Films written by Pratish Mahtani and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A fundamental study of the correlations between ion energy, substrate temperature, and plasma density with hydrogen content, percent sp2 bonding, optical gap, and refractive index of hydrogenated amorphous carbon (a-C) films is presented. A strong dependency between the ion energy used during deposition and the film's microstructure is shown. Moreover, it is revealed that the optical properties of the a-C films are controlled by the concentration and size of sp2 clusters in the film. Through N2 mixing in the source gas, room-temperature nitrogen doped polymeric-like a-C films were demonstrated for the first time. X-ray Photoelectron Spectroscopy revealed an increase in the Fermi level of these films with increased nitrogen content. A proof-of-concept a-C based transparent heat mirror (THM) was demonstrated. It was shown that a-C acts as an oxygen-free protective barrier and anti-reflective coating for Ag films in the THM, increasing the transmission in the visible region by 10-20%.
Book Synopsis Properties of Amorphous Carbon by : S. R. P. Silva
Download or read book Properties of Amorphous Carbon written by S. R. P. Silva and published by IET. This book was released on 2003 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: World experts in amorphous carbon have been drawn together to produce this comprehensive commentary on the current state and future prospects of amorphous carbon, a highly functional material. Amorphous carbon has a wide range of properties that are primarily controlled by the different bond hybridisations possible in such materials. This allows for the growth of an extensive range of thin films that can be tailored for specific applications. Films can range from those with high transparency and which are hard and diamond-like, through to those which are opaque, soft and graphitic-like. Application areas including field emission cathodes, MEMs, electronic devices, medical and optical coatings are now close to market.
Book Synopsis Preparation and Characterization of Amorphous Carbon Films by : Brian Sadao Shinseki
Download or read book Preparation and Characterization of Amorphous Carbon Films written by Brian Sadao Shinseki and published by . This book was released on 1988 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Sputtering Deposition and Characterization of Ultrathin Amorphous Carbon Films by : Wei Lu
Download or read book Sputtering Deposition and Characterization of Ultrathin Amorphous Carbon Films written by Wei Lu and published by . This book was released on 1999 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Synthesis, Characterization, and Molecular Dynamics Analysis of Ultrathin Amorphous Carbon Films by : Na Wang
Download or read book Synthesis, Characterization, and Molecular Dynamics Analysis of Ultrathin Amorphous Carbon Films written by Na Wang and published by . This book was released on 2013 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increasing demands for high magnetic storage capacity have led to the increase of the recording area density by more than 100,000 times over the past 30 years. Among all the approaches considered to increase the area density, reducing the magnetic spacing is an effective solution that directly impacts the thickness and quality of the carbon overcoat. One of the methods of carbon overcoat deposition is chemical vapor deposition, which uses carbon-containing precursor gases as the source of carbon radicals and atoms to form the carbon overcoat. The produced carbon film is characterized by high hydrogen content (20%-50%), depending on the carbon-to-hydrogen ratio of the precursor gas and process parameters. Because of the hydrogen content, CVD-deposited hydrogenated amorphous carbon (a-C:H) deposited by CVD exhibit density of 1.7-2.2 g/cm3, which is much lower than the density (~3 g/cm3) of hydrogen-free amorphous carbon (a-C) films deposited by filtered cathodic vacuum arc (FCVA). The superior nanomechanical/tribological properties of FCVA-deposited a-C films have been widely-reported; however, most studies have examined relatively thick (tens of nanometers) a-C films, while current demands require much thinner films of thickness in the range of 1-4 nm. FCVA-deposited a-C films overcoats are desirable protective overcoats for HDDs provided they can maintain their demonstrated high quality even for thickness as low as 1 nm. In this dissertation, an in-depth study of the structure of FCVA-deposited a-C films deposited on silicon was carried out using high-resolution transmission electron microscopy (HRTEM) and analytical electron energy loss spectroscopy (EELS). Both low- and high (core)-loss EELS spectra of Si and C were analyzed to determine the elemental content and through-thickness structure of ~20-nm-thick a-C films. Calculations of atomic carbon hybridization based on EELS spectra were used to track the film structure evolution. The average content of carbon hybridization in the top few nanometers of the a-C film, determined from EELS analysis, was found to be ~50%, much less than 73% of the bulk film. This multilayer structure was also validated by X-ray photoelectron spectroscopy (XPS). Results indicate that the minimum thickness of a-C films deposited by the FCVA method under conditions of optimum substrate bias ( -100 V) should be equal to 3-3.5 nm, which is the total thickness of the buffer and surface layers. The effects of other important FCVA process parameters on film growth were also investigated to explore the prospect of further decreasing the a-C film thickness. The incidence angle effect of energetic C+ ions bombarding onto the growing film surface was studied in terms of the deposition rate, topography, and film structure. Cross-section TEM measurements combined with Monte Carlo (T-DYN) simulations revealed that the deposition yield (rate) is independent of the ion fluence but varies with the incidence angle according to a relationship derived from sputtering theory. XPS and atomic force microscopy (AFM) studies were also performed to examine carbon hybridization and film topography. The optimum incidence angle for FCVA deposition was found equal to 45o. A relatively new technology that shows potential for further breakthroughs in magnetic recording is heat-assisted magnetic recording (HAMR). This technology utilizes a tightly focused laser beam to heat and temporarily reduce the coercivity of magnetic nanodomains below that of the magnetic field applied by the magnetic head. Impulsive laser heating (typically
Book Synopsis Tetrahedrally Bonded Amorphous Carbon Films I by : Bernd Schultrich
Download or read book Tetrahedrally Bonded Amorphous Carbon Films I written by Bernd Schultrich and published by Springer. This book was released on 2018-03-10 with total page 769 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the status quo of the structure, preparation, properties and applications of tetrahedrally bonded amorphous carbon (ta-C) films and compares them with related film systems. Tetrahedrally bonded amorphous carbon films (ta-C) combine some of the outstanding properties of diamond with the versatility of amorphous materials. The book compares experimental results with the predictions of theoretical analyses, condensing them to practicable rules. It is strictly application oriented, emphasizing the exceptional potential of ta-C for tribological coatings of tools and components.
Book Synopsis Synthesis and Characterization of Amorphous Carbon Films for Heat-Assisted Magnetic Storage by : Jozef Matlak
Download or read book Synthesis and Characterization of Amorphous Carbon Films for Heat-Assisted Magnetic Storage written by Jozef Matlak and published by . This book was released on 2017 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heat-assisted magnetic recording (HAMR) is a promising technology for next-generation magnetic storage devices that has the potential to increase magnetic recording density by orders of magnitude (up to 10 Tb/in2). By focusing a laser beam to rapidly heat the magnetic media above the Curie temperature, the coercivity of the magnetic domains over a small area can be sufficiently reduced to allow changes in polarization at a finer scale, thus enabling the reading and writing of data at much greater densities. Several factors, however, have prevented this technology from reaching the market. One major issue is the thermal stability of the amorphous carbon (a-C) overcoat on the magnetic head and its ability to protect critical components, such as read and write poles, near-field transducer, and waveguide, when heated to high temperatures during drive operation. This dissertation focuses on the optimization of a-C overcoats (also referred to as tetrahedral amorphous carbon (ta-C) due to the relatively high content of tetrahedral (sp3) carbon atom hybridization) deposited at very short deposition times (6 sec) and investigates the effects of heating on the nanostructure and intermixing with underlayers. As the overcoat thickness approaches only a few atomic layers, its performance and continuity become of concern, especially when exposed to higher temperatures. Since the tribomechanical and corrosion properties of carbon films have been correlated to the type of carbon atom hybridization, the choice of deposition technique and parameters to control the relative bonding content is crucial. Among the various deposition techniques, filtered cathodic vacuum arc (FCVA) was chosen to develop a-C protective overcoats. The energetic C+ ions film precursors in FCVA are especially beneficial for depositing continuous ultrathin a-C films with low surface roughness. Deposition parameters explored include the ion incidence angle and pulse substrate bias voltage under optimized duty cycle and ion fluence FCVA conditions, with the intent of minimizing a-C film thickness while maintaining adequate mechanical performance. Cross-sectional high-resolution transmission electron microscopy (HRTEM) and scanning transmission electron microscopy (STEM) coupled with electron energy loss spectroscopy (EELS) were used to reveal nanostructure variations along the through thickness of a-C films and carbon intermixing with the substrate. The optimized coatings were deposited on an assortment adhesion (NiCr), buffer (SiN, TaOx), and base layers (Au, FeCo) common to HAMR magnetic media and heated for 30 min to simulate accumulation of heating damage. For a-C films 2-3 nm thick, the highest sp3 content was found in the bulk layer and were synthesized under FCVA deposition conditions of 65% duty cycle and -25 to -75 V substrate bias. The HRTEM and EELS analysis revealed no changes in thickness and minor structural changes in the a-C overcoat and generally small amounts of intermixing between the overcoat and the underlayers when operated in an inert hot environment. The findings of this dissertation suggest that proper optimization of such layered coatings can provide a viable solution to thermal damage of HAMR heads.
Book Synopsis The Jarvis-Conklin Mortgage Trust Compamy, Kansas City, Mo by :
Download or read book The Jarvis-Conklin Mortgage Trust Compamy, Kansas City, Mo written by and published by . This book was released on with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Characterization of Amorphous Carbon Thin Films Using Raman Spectroscopy and Other Techniques by : Evan Murdock
Download or read book Characterization of Amorphous Carbon Thin Films Using Raman Spectroscopy and Other Techniques written by Evan Murdock and published by . This book was released on 1996 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis A Study of the Composition, Structure and Properties of Amorphous Hydrogenated Diamond-like Carbon Films by : David Eric Muller
Download or read book A Study of the Composition, Structure and Properties of Amorphous Hydrogenated Diamond-like Carbon Films written by David Eric Muller and published by . This book was released on 1994 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Nanostructural Characterization of Amorphous Diamondlike Carbon Films by :
Download or read book Nanostructural Characterization of Amorphous Diamondlike Carbon Films written by and published by . This book was released on 2000 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanostructural characterization of amorphous diamondlike carbon (a-C) films grown on silicon using pulsed-laser deposition (PLD) is correlated to both growth energetic and film thickness. Raman spectroscopy and x-ray reflectivity probe both the topological nature of 3- and 4-fold coordinated carbon atom bonding and the topographical clustering of their distributions within a given film. In general, increasing the energetic of PLD growth results in films becoming more ''diamondlike'', i.e. increasing mass density and decreasing optical absorbance. However, these same properties decrease appreciably with thickness. The topology of carbon atom bonding is different for material near the substrate interface compared to material within the bulk portion of an a-C film. A simple model balancing the energy of residual stress and the free energies of resulting carbon topologies is proposed to provide an explanation of the evolution of topographical bonding clusters in a growing a-C film.
Book Synopsis Growth and Characterization of Diamond and Diamond Like Carbon Films with Interlayer by : Roja Gottimukkala
Download or read book Growth and Characterization of Diamond and Diamond Like Carbon Films with Interlayer written by Roja Gottimukkala and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Diamond and diamond-like carbon films, with their exceptionally good mechanical, chemical, and optical properties, are the best materials as protective hard coatings for electronic devices and cutting tools. The biocompatibility of these materials makes it suitable for bone implants. The wide range applications of these films are hindered because of the high compressive stresses developed during the deposition. Use of carbide and nitride interfacial layers has emerged as one of the methods to reduce the compressive stresses. The present research focuses on the study of different materials as the interfacial layers for diamond and tetrahedral amorphous carbon films. For tetrahedral amorphous carbon AlN, Ta, TiN, TiC, TaN and W were investigated as the interlayer materials. The interlayer was deposited at different substrate temperatures to study the temperature induced changes in the residual stress. The tetrahedral amorphous carbon with TiN interlayer deposited at 300°C and 600°C exhibited a maximum reduction in the stress. TiN and TiC were deposited as interlayer for the diamond films on Ti-6Al-4V alloy. TiC has improved the adhesion of diamond with the substrate and exhibited less compressive stresses compared to TiN.
Book Synopsis Characterization of Thin Amorphous Hydrogenated Carbon Films Produced by Plasma Source Ion Implantation as Protective Coatings on Computer Hard Disks by : Robin Scott Peters
Download or read book Characterization of Thin Amorphous Hydrogenated Carbon Films Produced by Plasma Source Ion Implantation as Protective Coatings on Computer Hard Disks written by Robin Scott Peters and published by . This book was released on 1992 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
