Vertically self-organized gold nanoparticles in amorphous alumina matrices

2006 ◽  
Vol 960 ◽  
Author(s):  
Chunming Jin ◽  
Honghui Zhou ◽  
Wei Wei ◽  
Roger J. Narayan
Keyword(s):  
Gold Nanoparticles ◽  
Vertical Direction ◽  
Deposition Process ◽  
Film Deposition ◽  
Multilayered Structures ◽  
Cross Sectional ◽  
Self Organized ◽  
Growth Modes ◽  
Transmission Electron ◽  
Amorphous Alumina

ABSTRACTIn this study, self-organized growth of gold nanoparticles dispersed in amorphous alumina matrices was investigated. Au/Al2O3 multilayered structures were grown on silicon (001) substrates using pulsed laser deposition. Vertical ordering of particles was examined with cross-sectional transmission electron microscopy and image Fourier transformation. Self-organization of gold nanoparticles along the vertical direction was observed in the samples grown at room temperature and 320 °C. This process occurred through two-different growth modes, known as top-on-top growth and top-on-middle growth. The driving force for the vertical ordering was attributed to long-range elastic interactions among nanoparticles during the film deposition process.

scholarly journals Growth Kinetics of Thin Film Epitaxy

2020 ◽  
Author(s):  
Hong Liu
Keyword(s):  
Growth Stage ◽  
Deposition Process ◽  
Film Structure ◽  
Film Deposition ◽  
Diffusion Reaction ◽  
Growth Modes ◽  
Adsorption Surface ◽  
The Relationship ◽  
Thin Film Epitaxy ◽  
Kinetics Of

This chapter mainly introduces five basic stages of the film deposition process (vapor adsorption, surface diffusion, reaction between adsorbed species, reaction of film materials to form bonding surface, and nucleation and microstructure formation), analyzes the influence of deposition process parameters on the three basic growth modes of the film, focuses on the relationship between the control parameters of homoepitaxy and heteroepitaxy and the film structure, gives the dynamic characteristics of each growth stage, and examines the factors determining epitaxy film structure, topography, interfacial properties, and stress. It is shown that two-dimensional nucleation is a key to obtain high-quality epitaxial films.

Self-Healing and Self-Organized Gold Nanoparticle Films at a Water/Organic Solvent Interface

2006 ◽  
Vol 6 (1) ◽  
pp. 130-134 ◽  
Author(s):  
Olivier Balmes ◽  
Jan-Olov Bovin ◽  
Jan-Olle Malm
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gold Nanoparticles ◽  
Organic Solvent ◽  
Continuous Production ◽  
Self Healing ◽  
Self Organized ◽  
Transmission Electron ◽  
20 Nm

Gold nanoparticles (5 nm and 20 nm) have been synthesized and stabilized with mercaptoundecanol. These particles, although insoluble in water or common organic solvents, spread as a thin film at the liquid–liquid interface between a water phase and an organic phase. Films of these gold nanoparticles have been observed both by conventional transmission electron microscopy of deposited samples and by cryo-transmission electron microscopy of plunge-frozen samples. The film can be monolayered and extend over centimeter-sized areas. The particle films spontaneously re-assemble and self-organize at the interface when disrupted. This self-healing capacity of the film should make it possible to build a device for continuous production and deposition of the film.

Sputter Deposition of CuInSe2 and CuGaSe2 from Composite Targets on (100) Si

2009 ◽  
Vol 1210 ◽  
Author(s):  
Okechukwu N. Akpa ◽  
Shaik Shoieb ◽  
Trenton R. Thompson ◽  
Tamara F. Isaacs-Smith ◽  
Philip Anderson ◽  
...  
Keyword(s):  
Hall Mobility ◽  
Rf Magnetron Sputtering ◽  
Film Structure ◽  
Rutherford Backscattering ◽  
Film Deposition ◽  
Native Oxide ◽  
Cross Sectional ◽  
Si Substrates ◽  
Transmission Electron ◽  
Contamination Levels

AbstractThin films of CuInSe2 (CIS) and CuGaSe2 (CGS) were deposited on (100) Si substrates by RF magnetron sputtering using stoichiometric targets, at various substrate temperatures. Prior to film deposition, the Si substrates were cleaned using the RCA cleaning procedure and treated in a buffered oxide etch (BOE) solution. Deposited films were characterized using Rutherford backscattering spectroscopy (RBS), transmission electron microscopy (TEM) of cross-sectional samples and Hall measurements. Rutherford backscattering analysis indicated that the CIS films had a composition of Cu0.8In1.1Se1.9, whereas CGS films were Cu-poor and Ga-rich with a composition of Cu0.3Ga1.5Se1.5. Clean Cu-chalcopyrite/Si interfaces were obtained using BOE treated Si substrates. Transmission electron micrographs of cross-sectional samples indicated a polycrystalline film structure and that the native oxide on the Si substrate was eliminated. Energy dispersive X-ray spectroscopy (EDS) conducted in the TEM showed that contamination levels in the films were low. The Hall-mobility experiments performed the CIS film indicated that the material was of p-type conductivity with a carrier concentration of 9.6 x 1020/cm3 and a Hall mobility of 390 cm2V-1s-1.

Characteristics of Thick Film Deposition in Powder Jet Machining

2013 ◽  
Vol 7 (6) ◽  
pp. 630-637
Author(s):  
Chihiro Nishikawa ◽  
◽  
Naohide Mizukuchi ◽  
Akihiko Tomie ◽  
Keita Shimada ◽  
...  
Keyword(s):  
Deposition Process ◽  
Film Deposition ◽  
Abrasive Jet Machining ◽  
Material Deposition ◽  
Transmission Electron ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Impact Phenomena ◽  
Deposition Processes ◽  
The Impact

Powder jet machining can be used for both material removal (abrasive jet machining) and material deposition processes (powder jet deposition) by changing the powder spray conditions. The transition from the removal to the deposition is investigated. The transition between these two phenomena, removal and deposition, is studied through simulating the impact phenomena of two alumina particles with a glass substrate using the Smoothed Particle Hydrodynamics (SPH) method in this study. Crystalline structures of an alumina film created were observed with a Transmission Electron Microscope (TEM). Observation indicates that a thick multicrystalline film is created when the blasted particles are monocrystalline alumina. It is also concluded that fractures within the particle material are necessary for the deposition process, and that fragments less than 100 nm in size contribute to the deposition of the thick films.

Polycrystalline β-SiC Film Growth on Si by ECR-CVD at 178 - 500°C

1995 ◽  
Vol 403 ◽  
Author(s):  
Kuan-Lun Cheng ◽  
Chih-Chien Liu ◽  
Chung-Min Fu ◽  
Huang-Chung Cheng ◽  
Chiapyng Lee ◽  
...  
Keyword(s):  
Electron Cyclotron Resonance ◽  
Film Growth ◽  
Film Surface ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Dark Field ◽  
Cross Sectional ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
Field Imaging

AbstractPolycrystalline β-SiC, with grain size up to 0.2 μm, was grown on silicon substrate by electron cyclotron resonance chemical vapor deposition (ECR-CVD) from SiH4/CH4/H2 at 178–500 °C. The nucleation process and surface structure of polycrystalline SiC were investigated via observing the film surface by atomic force microscopy (AFM). Reaction species which promote polycrystalline SiC was in-situ monitored by quadruple mass spectrum analysers during deposition process, which is crucial for the control of polycrystalline SiC growth. The microstructure of SiC films were inspected by bright-field imaging, dark-field imaging, and electron diffraction in cross-sectional transmission electron microscopy. This paper will also discuss the key parameters for the nucleation and growth of polycrystalline β-SiC at very low temperature in ECR-CVD system.

characterization of amorphization in Ni-Ti multilayers

1988 ◽  
Vol 46 ◽  
pp. 452-453
Author(s):  
K. B. Alexander ◽  
F. J. Walker ◽  
R. A. McKee ◽  
F. A. List
Keyword(s):  
Amorphous Film ◽  
High Energy ◽  
Film Deposition ◽  
Cross Sectional ◽  
Transmission Electron ◽  
20 Nm ◽  
Elemental Layer ◽  
Deposited Films

The formation of amorphous alloys through the solid-state reaction of crystalline multilayers has recently been studied by several groups. In each of these studies, the multilayers were entirely amorphous when there were less than 4-10 planes in each layer. Layer thicknesses larger than this resulted in crystalline layers, presumably separated by an amorphous film approximately 4-10 layers thick. Our intent was to measure the thickness of the amorphous film in Ni-Ti multilayer specimens with a wavelength (thickness of Ni + Ti layers) of 20 nm, or approximately 40 planes per elemental layer. In situ Reflection High Energy Electron Diffraction (RHEED) was performed during the film deposition and transmission electron microscopy of cross-sectional specimens was used to examine the as-deposited films.Nickel and titanium layers were sequentially deposited onto a 50 nm amorphous Ni-Ti codeposit on an unheated (001) silicon substrate in the ORNL Molecular Beam Epitaxy (MBE) facility with a vacuum < 10-9 torr.

scholarly journals Temperature Dependent 4-, 5- and 6-Fold Coordination of Aluminum in MOCVD-Grown Amorphous Alumina Films: From Local Coordination to Material Properties

2014 ◽  
Vol 91 ◽  
pp. 123-133 ◽  
Author(s):  
Alain N. Gleizes ◽  
D. Samélor ◽  
Constantin Vahlas ◽  
Vincent Sarou-Kanian ◽  
Pierre Florian ◽  
...  
Keyword(s):  
Aluminum Oxide ◽  
Amorphous State ◽  
Chemical Vapor ◽  
Structural Disorder ◽  
Thin Film Deposition ◽  
Deposition Process ◽  
Film Deposition ◽  
Nmr Analysis ◽  
Al Content ◽  
Amorphous Alumina

Aluminum 5-fold coordination coexisting with 4-and 6-fold coordination structurally characterizes amorphous aluminum oxide. For nearly 30 years now,27Al MAS NMR has enabled to detect and later on to quantify this feature thanks to advances in high-resolution instrumentation. The Introduction shortly reviews the results of investigations of 5-coordinate aluminum in amorphous alumina through NMR analysis. Aluminum oxide is not a glass-forming oxide. A convenient way to obtain the amorphous state is by thin film deposition. We present here27Al NMR analysis of a series of thin films of aluminum oxide prepared by metalorganic chemical vapor deposition (MOCVD) in the temperature range 360 ≤ Td≤ 720 °C. In this range, low Tdyield OH-containing films, while high Tdyield nanocrystallites-containing films. The variation of the[4]Al,[5]Al and[6]Al content with Tdis presented and discussed. It is correlated with the Tddependence of mechanical and corrosion protection properties. These properties are optimal when the structural disorder is to the utmost. Al coordination dependence on film thickness and the formation of metallic aluminum during the deposition process are also presented.

Improved magnetic properties of self-assembled epitaxial nickel nanocrystallites in thin-film ceramic matrix

2002 ◽  
Vol 17 (4) ◽  
pp. 738-742 ◽  
Author(s):  
D. Kumar ◽  
H. Zhou ◽  
T. K. Nath ◽  
Alex V Kvit ◽  
J. Narayan ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Particles ◽  
Deposition Process ◽  
Hysteretic Behavior ◽  
Blocking Temperature ◽  
Alumina Matrix ◽  
Cross Sectional ◽  
Two Samples ◽  
The Matrix ◽  
Amorphous Alumina

Nanocrystalline nickel particles were embedded in amorphous alumina and crystalline TiN matrices using a pulsed laser deposition process to investigate the effect of texturing on magnetic properties of nickel nanocrystallites. The crystalline quality of both the matrix and magnetic particles was investigated by cross-sectional high-resolution transmission electron microscopy. The embedded Ni nanocrystals were found to be epitaxial in the case of the TiN matrix and polycrystalline in Al2O3 amorphous matrix. The Ni nanocrystals on TiN/Si grow epitaxially because the TiN acting as a template grows epitaxially on Si substrate via domain epitaxy. On the other hand, Ni nanocrystals in the Al2O3 matrix are polycrystalline because of the amorphous nature of the alumina matrix. Magnetization versus temperature measurements have shown that the blocking temperature, above which the samples lose magnetization–field (M–H) hysteretic behavior, of the Ni–TiN sample (approximately 190 K) is significantly higher than that of Ni–Al2O3 sample (approximately 30 K) with a similar size distribution of embedded magnetic particles. A comparison of the values of coercivity (Hc) of the two samples, measured from M–H data, indicates that epitaxial Ni nanocrystals also exhibit significantly higher coercivity than polycrystalline Ni particles in amorphous alumina matrix. The high values of TB and Hc of Ni–TiN samples with respect to TB of N–A12O3 samples are believed to be associated with preferred alignment of nanocrystallites.

A Study of the MBE HgTe Growth Process

1986 ◽  
Vol 90 ◽  
Author(s):  
Roland J. Koestner ◽  
H. F. Schaake
Keyword(s):  
Electron Microscopy ◽  
Growth Process ◽  
Substrate Surface ◽  
Flux Ratio ◽  
Important Application ◽  
Multilayered Structures ◽  
Cross Sectional ◽  
Mbe Growth ◽  
Growth Orientation ◽  
Transmission Electron

ABSTRACTThe MBE growth of HgTe on CdTe is examined over a hundred-fold range in Hg/Te2 flux ratio and over four separate substrate surface orientations [(111)Te, (111)Te-4 degrees, (112)Te and (001)]. The 77K Hall mobility of the (112)Te and (001) oriented HgTe layers approaches the best bulk values reported to date, although our (111)Te and (111)Te-4 deg oriented HgTe films yield much lower values. The growth process is shown to be very far from thermodynamic equilibrium at our optimal substrate temperature and calculated equivalent Hg beam pressure. Important clues to help understand the kinetics governing the HgTe growth process are uncovered by studying the defects that form under Hg- or Te-rich conditions with cross-sectional transmission electron microscopy (XTEM). Since multilayered structures are an important application for MBE growth of Hg-based semiconductors, we have also examined the interfacial roughness present in HgTe-CdTe superlattices (SL) as a function of growth orientation.

A Field Emission System For Transmission Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 298-299
Author(s):  
Michel Troyonal ◽  
Huei Pei Kuoal ◽  
Benjamin M. Siegelal
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Optical System ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Objective Lens ◽  
Electron Optical System ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Emission System

A field emission system for our experimental ultra high vacuum electron microscope has been designed, constructed and tested. The electron optical system is based on the prototype whose performance has already been reported. A cross-sectional schematic illustrating the field emission source, preaccelerator lens and accelerator is given in Fig. 1. This field emission system is designed to be used with an electron microscope operated at 100-150kV in the conventional transmission mode. The electron optical system used to control the imaging of the field emission beam on the specimen consists of a weak condenser lens and the pre-field of a strong objective lens. The pre-accelerator lens is an einzel lens and is operated together with the accelerator in the constant angular magnification mode (CAM).

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