ELASTIC PROPERTIES OF METAL SUPERLATTICES

1985 ◽  
Vol 56 ◽  
Author(s):  
A.F. JANKOWSKI ◽  
T. TSAKALAKOS
Keyword(s):  
Thin Film ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Vapor Deposition ◽  
Short Wavelength ◽  
Plastic Behavior ◽  
Average Composition ◽  
Strain Effects ◽  
Modulated Structure ◽  
Appreciable Increase

AbstractThe elastic properties of modulated structure materials are presented. An enhanced modulus effect has been observed in several composition modulated thin film systems containing short wavelength modulations.8-10nm. The foils were produced by vapor deposition using two or three source evaporator. As compared with homogeneous foils of the same average composition, the modulated foils exhibited an appreciable increase (up to 300%) in modulus. The dependence of various moduli on the modulation parameters (wavelength, composition and amplitude) are described. The plastic behavior, breaking and microhardness of these foils are also presented as a function of the modulation parameters. Current theories based on electronic and strain effects on the elastic constants of metals are also presented to explain the origin of the supermodulus effect.

Mechanical Properties of Composition Modulated Copper-Nickel-Iron Thin Films

1984 ◽  
Vol 37 ◽  
Author(s):  
A. F. Jankowski ◽  
T. Tsakalakos
Keyword(s):  
Vapor Deposition ◽  
Tensile Testing ◽  
Lattice Misfit ◽  
X Ray Diffraction ◽  
Average Composition ◽  
X Ray ◽  
Nickel Iron ◽  
Thin Foils ◽  
Appreciable Increase ◽  
Spectroscopy Studies

AbstractThe enhanced elastic modulus effect was found in composition modulated Cu/NiFe foils. Young's modulus was measured via tensile testing on thin foils containing short-wavelength composition modulations of 1.4–10. nm. The foils, of 53% Cu -40% Ni -7% Fe composition, were produced by vapor deposition using a three-source evaporator. As compared with homogeneous foils of the same average composition, the modulated foils exhibited an appreciable increase (up to 300%) in modulus for two distinct ranges of compositon wavelength: 2.1–2.7 nm and 3.6–4.1 nm. Results of x-ray diffraction and Mossbauer spectroscopy studies suggest the concept of interfacial coherency, accommodating the lattice misfit between the composition layers, is the underlying structural feature responsible for the enhanced modulus effect.

Reaction couples of ceramic thin films prepared by CVD

1988 ◽  
Vol 46 ◽  
pp. 798-799
Author(s):  
D.W. Susnitzky ◽  
S.R. Summerfelt ◽  
C.B. Carter
Keyword(s):  
Thin Film ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Solid State Reactions ◽  
Spatial Distributions ◽  
Diffusion Couples ◽  
Kinetics Studies ◽  
Ceramic Thin Films ◽  
Initial Stage

Solid-state reactions have traditionally been studied in the form of diffusion couples. This ‘bulk’ approach has been modified, for the specific case of the reaction between NiO and Al2O3, by growing NiAl2O4 (spinel) from electron-transparent Al2O3 TEM foils which had been exposed to NiO vapor at 1415°C. This latter ‘thin-film’ approach has been used to characterize the initial stage of spinel formation and to produce clean phase boundaries since further TEM preparation is not required after the reaction is completed. The present study demonstrates that chemical-vapor deposition (CVD) can be used to deposit NiO particles, with controlled size and spatial distributions, onto Al2O3 TEM specimens. Chemical reactions do not occur during the deposition process, since CVD is a relatively low-temperature technique, and thus the NiO-Al2O3 interface can be characterized. Moreover, a series of annealing treatments can be performed on the same sample which allows both Ni0-NiAl2O4 and NiAl2O4-Al2O3 interfaces to be characterized and which therefore makes this technique amenable to kinetics studies of thin-film reactions.

The relaxation of compressive biaxial strains in SOS via microtwins

1989 ◽  
Vol 47 ◽  
pp. 608-609
Author(s):  
M. E. Twigg ◽  
E. D. Richmond ◽  
J. G. Pellegrino
Keyword(s):  
Thin Film ◽  
Chemical Vapor Deposition ◽  
Molecular Beam Epitaxy ◽  
Compressive Stress ◽  
Vapor Deposition ◽  
Partial Dislocation ◽  
Molecular Beam ◽  
Volume Fraction ◽  
Chemical Vapor ◽  
Silicon Thin Film

For heteroepitaxial systems, such as silicon on sapphire (SOS), microtwins occur in significant numbers and are thought to contribute to strain relief in the silicon thin film. The size of this contribution can be assessed from TEM measurements, of the differential volume fraction of microtwins, dV/dν (the derivative of the microtwin volume V with respect to the film volume ν), for SOS grown by both chemical vapor deposition (CVD) and molecular beam epitaxy (MBE).In a (001) silicon thin film subjected to compressive stress along the [100] axis , this stress can be relieved by four twinning systems: a/6[211]/( lll), a/6(21l]/(l1l), a/6[21l] /( l1l), and a/6(2ll)/(1ll).3 For the a/6[211]/(1ll) system, the glide of a single a/6[2ll] twinning partial dislocation draws the two halves of the crystal, separated by the microtwin, closer together by a/3.

Low-Temperature Formation of SiNx Gate Insulator for Thin-Film Transistor Using CAT-CVD Method

1998 ◽  
Vol 508 ◽  
Author(s):  
A. Izumi ◽  
T. Ichise ◽  
H. Matsumura
Keyword(s):  
Thin Film ◽  
Chemical Vapor Deposition ◽  
Silicon Nitride ◽  
Vapor Deposition ◽  
Thin Film Transistors ◽  
Chemical Vapor ◽  
State Density ◽  
Gate Insulator ◽  
Catalytic Chemical Vapor Deposition ◽  
Silicon Nitride Films

AbstractSilicon nitride films prepared by low temperatures are widely applicable as gate insulator films of thin film transistors of liquid crystal displays. In this work, silicon nitride films are formed around 300 °C by deposition and direct nitridation methods in a catalytic chemical vapor deposition system. The properties of the silicon nitride films are investigated. It is found that, 1) the breakdown electric field is over 9MV/cm, 2) the surface state density is about 1011cm−2eV−1 are observed in the deposition films. These result shows the usefulness of the catalytic chemical vapor deposition silicon nitride films as gate insulator material for thin film transistors.

Polymer layers by initiated chemical vapor deposition for thin film gas barrier encapsulation

2011 ◽  
Vol 519 (14) ◽  
pp. 4479-4482 ◽  
Author(s):  
D.A. Spee ◽  
R. Bakker ◽  
C.H.M. van der Werf ◽  
M.J. van Steenbergen ◽  
J.K. Rath ◽  
...  
Keyword(s):  
Thin Film ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Gas Barrier ◽  
Polymer Layers ◽  
Initiated Chemical Vapor Deposition
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