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Showing papers on "Amorphous solid published in 1983"


Book
01 Jan 1983
TL;DR: The formation of amorphous solids Amorphous Morphology: The Geometry and Topology of Disorder Chalcogenide Glasses and Organic Polymers The Percolation Model Localization Delocalization Transitions Optical and Electrical Properties Index as discussed by the authors.
Abstract: The Formation of Amorphous Solids Amorphous Morphology: The Geometry and Topology of Disorder Chalcogenide Glasses and Organic Polymers The Percolation Model Localization Delocalization Transitions Optical and Electrical Properties Index.

2,051 citations


Book ChapterDOI
F. E. Luborsky1
01 Jan 1983

1,178 citations


Journal ArticleDOI
TL;DR: In this article, a free-energy diagram is used to explain the single-phase amorphous product of pure polycrystalline Au and La thin films at temperatures of 50-80°C.
Abstract: Single-phase Au1-xLax alloys, with 0.3≲x≲0.5, have been formed through solid-state interdiffusion of pure polycrystalline Au and La thin films (100-600 A) at temperatures of 50-80°C. The reaction is driven by the large negative heat of mixing in the amorphous alloy and occurs at low temperatures by the anomalously fast diffusion of Au in La. The composition regime giving a single-phase amorphous product is explained with use of a free-energy diagram.

1,009 citations


Journal ArticleDOI
TL;DR: In this paper, X-ray diffraction was used to follow the progress of the mechanical alloying which eventually produced "amorphous" diffraction patterns similar to those for liquid quenched amorphous Ni60Nb40.
Abstract: ‘‘Amorphous’’ Ni60Nb40 has been prepared by mechanical alloying of elemental nickel and niobium powders in a laboratory ball mill in controlled environments. X‐ray diffraction was used to follow the progress of the mechanical alloying which eventually produced ‘‘amorphous’’ diffraction patterns similar to those for liquid quenched amorphous Ni60Nb40. Crystallization behavior was measured by differential scanning calorimetry for the mechanically alloyed and liquid quenched material. The differences that were observed in this behavior, and in the products of crystallization, may be attributed to impurities (especially oxygen) introduced during mechanical alloying.

1,001 citations


Journal ArticleDOI
TL;DR: In this article, the authors show that the amorphous domains of polymers containing solvating heteroatoms form conductive complexes with low lattice energy alkali salts, which open a new field in solid-state electrochemistry.

622 citations


Journal ArticleDOI
TL;DR: Amorphous hydrogenated carbon thin films (a-C:H) were prepared by r.f. plasma deposition from benzene vapor and optical absorption in the range 0.2-25.0 μm was measured and used for bonding analysis as discussed by the authors.

604 citations



Journal ArticleDOI
TL;DR: In this article, the authors describe the deposition of amorphous hydrogenated hard carbon (a-C:H) thin films from benzene vapor in a rf plasma.
Abstract: The deposition of amorphous hydrogenated hard carbon (a–C:H) thin films from benzene vapor in a rf plasma is described. a–C:H was deposited on glass, quartz, Si, Ge, and GaAs. Negative self‐bias VB and gas pressure P are shown to be the two significant parameters for an accurate control of the deposition process. The dependence of growth rate and deposition temperature on VB and P was determined; this gives an empirical relation for the average energy E of the ions forming the thin films. Refractive index (1.85–2.20 in the IR), optical gap (0.8–1.8 eV) and density (1.5–1.8 g/cm3) of a–C:H was measured. The optical gap varies linearly with the content of bonded hydrogen in the films. The density of a–C:H is proportional to the average ion energy E. We demonstrate the application of a–C:H as antireflective coating on Ge for 10.6 μm (reflection <0.2% at 10.6 μm) and as terminating layer of an optical multilayer stack.

471 citations


Journal ArticleDOI
TL;DR: In this paper, a theoretical model for relaxation in glassy materials, in particular metallic glasses, based on a spectrum of available processes distributed in activation energy is presented, where direct comparison is possible between the theory and experiment the agreement is good over all these various observed phenomena.
Abstract: A theoretical model for relaxation in glassy materials, in particular metallic glasses, based on a spectrum of available processes distributed in activation energy is presented. The model is used to discuss “In t” kinetics, “reversibility” and “crossover” effects which have been observed experimentally. Where direct comparison is possible between the theory and experiment the agreement is good over all these various observed phenomena.

400 citations


Journal ArticleDOI
H. W. Spiess1
TL;DR: Pulsed deuteron NMR spectroscopy is described in this paper, which has recently been developed to become a powerful tool for studying molecular dynamics in solid polymers, and motional heterogeneities in glassy polymers can be detected.
Abstract: Pulsed deuteron NMR spectroscopy is described, which has recently been developed to become a powerful tool for studying molecular dynamics in solid polymers. It is shown that by analyzing the line shapes of2H absorption spectra and spectra obtained via solid echo and spin alignment, respectively, both type and timescale of rotational motions can be determined over an extraordinary wide range of characteristic frequencies, approximately 10 MHz to 1 Hz. By applying these techniques to selectively deuterated polymers, motional mechanisms involving different segments of the monomer unit can be monitored. In addition, motional heterogeneities in glassy polymers can be detected. The information about polymer dynamics available now is illustrated by a number of experimental examples. The chain motion in the amorphous regions of linearpolyethylene is discussed in detail and it is shown that it can clearly be distinguished from the chain motion of an amorphous polymer above the glass transition, wherepolystyrene is used as an example. Localized motions in the glassy state are illustrated through the jump motion phenyl groups exhibit both in the main chain (polycarbonate) and as a side group (polystyrene). The latter polymers also serve as examples for detecting motional heterogeneity. Finally, the mobility in novel classes of systems,liquid crystalline polymers andpolymer model membranes as revealed by2H NMR are described.

388 citations


Journal ArticleDOI
TL;DR: In this article, the optical gap depends linearly on hydrogen content and Eopt can be varied between 0.8 and 1.8 eV, where sp3 (single) and sp2 (double) C-C bonds dominate.
Abstract: Hydrogenated amorphous (a‐C:H) films were prepared by rf‐plasma deposition from benzene vapor. Complete optical absorption spectra from the UV to the IR (0.2–20.0 μm) have been measured. The optical gap depends linearly on hydrogen content and Eopt can be varied between 0.8 and 1.8 eV. For energies below Eopt the films are almost transparent and absorption is especially low in the 2–6‐μm region (e.g., α=15 cm−1 at λ=2.8 μm). Sharp C–H stretch absorption bands occur near 3.4 μm, giving insight into the microstructure of the films. A newly reported weak band at 3.03 μm is first evidence for C–C triple bonds (sp1 hybridization) in a‐C:H, where sp3 (single) and sp2 (double) C–C bonds dominate.

Journal ArticleDOI
TL;DR: The most important instability mechanism in amorphous silicon-silicon nitride thin-film transistors is charge trapping in the silicon nitride layer, which leads to a threshold voltage shift (ΔVT).
Abstract: The most important instability mechanism in amorphous silicon‐silicon nitride thin‐film transistors is charge trapping in the silicon nitride layer, which leads to a threshold voltage shift (ΔVT). We have measured the time, temperature, and gate voltage dependence of ΔVT and conclude that the rate limiting process, in the charge transfer from semiconductor to insulator, is the conduction in the nitride by variable‐range hopping. The threshold shift (under positive bias) is temperature dependent with an activation energy of 0.3 eV. This activation energy is identified with the mean hop energy required to inject charge deep into the silicon nitride at the low applied fields appropriate to transistor operation.

Journal ArticleDOI
TL;DR: The transition from the crystalline to the amorphous phase can be explained in terms of a "chemical frustration" effect as discussed by the authors, and the transition can be confirmed using X-ray diffraction patterns, density measurements, and superconducting properties.
Abstract: Noncrystalline metallic hydrides can be formed from certain crystalline Zr3Rh intermetallic phases by hydrogenation. X-ray diffraction patterns, density measurements, and superconducting properties confirmed the transition from the crystalline to the amorphous phase by this solid state reaction. The transition can be explained in terms of a "chemical frustration" effect.

Journal ArticleDOI
TL;DR: In this article, a tetragonal ZrO2 powder was prepared by hydrothermal treatment at 100 MPa of amorphous hydrous zirconia with distilled water and LiCl and KBr solutions.
Abstract: Ultrafine tetragonal ZrO2 powder was prepared by hydrothermal treatment at 100 MPa of amorphous hydrous zirconia with distilled water and LiCl and KBr solutions. The resulting powder consisted of well-crystallized particles; at 200°C, the particle size was 16 nm and at 500°C, 30 nm. Under hydrothermal conditions tetragonal ZrO2 appears to crystallize topotactically on nuclei in the amorphous hydrous zirconia.

Journal ArticleDOI
Charles Angell1
TL;DR: In this paper, the authors define a decoupling index R τ, 1 τ 13, which describes how well the (fast ion) conducting modes are decoupled from the amorphous matrix.

Journal ArticleDOI
G. Hertel1, David J. Bishop1, E. G. Spencer1, J. M. Rowell1, Robert C. Dynes1 
TL;DR: In this paper, tunneling and conductivity measurements through the metal-insulator transition in amorphous polysilicon are reported, and the results as a function of voltage, temperature and concentration are compared with current theoretical predictions.
Abstract: Tunneling and conductivity measurements through the metal-insulator transition in amorphous ${\mathrm{Nb}}_{x}{\mathrm{Si}}_{1\ensuremath{-}x}$ are reported. The authors observe the correlation gap $\ensuremath{\Delta}$ which varies with resistivity and have related this to the metal-insulator transition as observed in the conductivity. The samples were prepared by a process which allows precise control of the Nb concentration. The results as a function of voltage, temperature, and concentration are compared with current theoretical predictions.

Journal ArticleDOI
TL;DR: In this paper, a sufficient condition was established that an amorphous binary alloy will be formed by ion mixing of multilayered samples when the two constituent metals are of different crystalline structure, regardless of their atomic sizes and electronegativities.
Abstract: We formulate a rule which establishes a sufficient condition that an amorphous binary alloy will be formed by ion mixing of multilayered samples when the two constituent metals are of different crystalline structure, regardless of their atomic sizes and electronegativities. The rule is supported by the experimental results we have obtained on six selected binary metal systems, as well as by the previous data reported in the literature. The amorphization mechanism is discussed in terms of the competition between two different structures resulting in frustration of the crystallization process.

Journal ArticleDOI
TL;DR: In this article, the authors derived the optical constants of hard amorphous carbon films (aC:H) prepared by plasma decomposition of benzene and showed that 13 of the carbon atoms are trigonally bonded and 273 of the atoms are tetrahedrally bonded.

Journal ArticleDOI
TL;DR: Amorphization by ion beam irradiation of multilayered samples of Al/Pt, Al /Pd, and Al/Ni has been investigated by selected area diffraction and Rutherford backscattering as discussed by the authors.
Abstract: Amorphization by ion beam irradiation of multilayered samples of Al/Pt, Al/Pd, and Al/Ni has been investigated by selected area diffraction and Rutherford backscattering. With a dose of 2×1014 Xe ions/cm2, uniform mixing is achieved in the Al/Pt system and the amorphous phase is produced over a large composition range. In the Al/Pd and Al/Ni systems, amorphous phases or the equilibrium, crystalline phases are formed depending on the composition of the films. The same results were found when the samples were annealed to form crystalline phases before bombardment. For thin films of these fcc metals, only the simplest intermetallics, NiAl and PdAl, (primitive cubic structures with 2 atoms/cell) were formed in crystalline form by ion‐beam irradiation.

Journal ArticleDOI
TL;DR: Li/Li3.6Si0.4O4/TiS2 has been studied and cell performance evaluated in this paper, where the electrolyte thin film developed was amorphous, ionic conductivity was 5×10−6 (ohm cm)−1 and its Li+ transference number was 1.0.

Journal ArticleDOI
TL;DR: The doublet structure of the infrared absorption in the silicon-hydrogen stretch region for amorphous silicon is attributed mainly to environmental effects rather than to different SiH x (x = 1,2,3) groups.

Journal ArticleDOI
TL;DR: In this article, a variety of intermetallic compounds have been irradiated with high energy ions to determine the criteria for an amorphous transformation, and the ionicity criterion of Naguib and Kelly does not work for these intermetall compounds, but the temperature criterion is probably valid and is directly related to the proposed solubility criterion.
Abstract: A variety of intermetallic compounds have been irradiated with high energy ions to determine the criteria for an amorphous transformation. Those compounds with limited compositional range or solubility tend to become amorphous during irradiation, whereas those compounds with wide solubility tend to remain crystalline. This solubility criterion is consistent with the concept that a critical defect density which will result in a greater free energy of the crystal phase than the free energy of the amorphous phase is necessary for the amorphous transformation. This critical defect density is lower in those compounds that become amorphous. The ionicity criterion of Naguib and Kelly does not work for these intermetallic compounds, but the temperature criterion is probably valid and is, in fact, directly related to the proposed solubility criterion.

Patent
Joseph Zelez1
03 Nov 1983
TL;DR: An amorphous, carbonaceous, diamond-like film and a process for producing the same is disclosed in this paper, which is a hybrid process using radio frequency plasma decomposition of an alkane and a pair of spaced carbon electrodes.
Abstract: An amorphous, carbonaceous, diamond-like film and a process for producing the same is disclosed. The film has an extremely low hydrogen content and an extremely low stress, is resistant to both acids and alkalis, and adheres tenaciously to many types of substrates including glasses, plastics, metals, and semiconductors. The process for producing this film is a hybrid process using radio frequency plasma decomposition of an alkane and a pair of spaced carbon electrodes.

Journal ArticleDOI
TL;DR: In this paper, a simple model for the description of this polarization in non-crystalline SiO2 is developed and used for the calculation of the density of states of LO and TO phonons in the framework of a coherent potential approximation for structurally disordered systems.
Abstract: Until now there exists no calculation of the phonon density of states of amorphous SiO2 and related materials, which could interpret the experimentally detected splittings between longitudinal and transverse modes in their optical phonon spectra. This problem is solved by taking into account the influence of the vibrationally induced polarization on the motion of atoms. A simple model for the description of this polarization in non-crystalline SiO2 is developed and used for the calculation of the density of states of LO and TO phonons in the framework of a coherent potential approximation for structurally disordered systems. This new method leads also to the determination of the IR response function and to simple analytical expressions for the microscopic parameters of the model, i.e. the bond angle at the oxygen atom and transverse dynamic effective charges. The values of these parameters are determined from IR transmission spectra of thin SiO2 layers prepared with the help of different methods. The calculated density of states and IR response function are in good agreement with corresponding experimental results.

Journal ArticleDOI
TL;DR: In this paper, the authors used backscattering spectrometry and glancing-angle x-ray diffraction to investigate the silicide formation with single crystal Si and amorphous Si.
Abstract: Silicide formation with Ti deposited on single crystal Si and Ti deposited on amorphous Si layers sequentially without breaking the vacuum was investigated using backscattering spectrometry and glancing-angle x-ray diffraction. For Ti deposited on amorphous Si, TiSi2 was formed with a rate proportional to (time)^1/2 and an activation energy of 1.8±0.1 eV. For Ti deposited on single crystal Si, the reaction rate was slower and the silicide layer was nonuniform in thickness. We attribute the difference in behavior to the presences of interfacial impurities in the case where Ti was deposited on single crystal Si.

Journal ArticleDOI
TL;DR: In this article, an electron diffraction analysis provides information about the cluster structure and dynamics, showing that the largest clusters exhibit mainly a crystalline structure, namely, diamond cubic which is the metastable phase of bulk solid water.
Abstract: Clusters are produced in a free jet expansion of water vapor. Keeping constant the nozzle diameter (d=0.4 mm) and temperature (T=430 K), an increase in inlet vapor pressure from 1 to 5 bar produces an increase in mean cluster size from several tens to several thousands of molecules per cluster. An electron diffraction analysis provides information about the cluster structure and dynamics. A direct observation of diffraction patterns shows that the largest clusters exhibit mainly a crystalline structure, namely, diamond cubic which is the metastable phase of bulk solid water, whereas the smallest ones are amorphous. In order to elucidate the local order in the latter, a comparison is made between the experimental curves and the diffraction functions calculated for various noncrystalline models. The best agreement is obtained with a model which presents distorted rings of three to six H2O molecules, constructed by cooling a liquid water droplet through a molecular dynamics calculation. In particular, this m...

Journal ArticleDOI
TL;DR: In this article, the authors used hydrogen evolution and annealing experiments to investigate the incorporation of hydrogen in the amorphous network and the mechanism of its release, showing that hydrogen appears to be bonded mainly at positions breaking Si-Si bonds so that at its release these bonds are reconstructed.
Abstract: Hydrogen evolution and annealing experiments are used to investigate the incorporation of hydrogen in the amorphous network and the mechanism of its release. For a hydrogen content 20 at.% leads to the formation of a void-rich material. In both cases hydrogen appears to be bonded mainly at positions breaking SiSi bonds so that at its release these bonds are reconstructed. The evolution and annealing behavior is strongly modified if additional structural defects are present, for instance due to boron doping.

Journal ArticleDOI
TL;DR: In this article, the authors used an adaptation of an algorithm due to Moynihan using parameter values determined from an analysis of the glass transition kinetics of a single thermal history.
Abstract: The relaxation component of the heat capacity at constant heating rate (10 K min -1) of a polydisperse polystyrelie as a function of previous cooling rate, annealing time, and annealing temperature is accurately predicted by an adaptation of an algorithm due to Moynihan using parameter values determined from an analysis of the glass transition kinetics of a single thermal history. For this material, the annealing behavior below Tg is determined by the same kinetic parameters that describe the glass transition phenomenon. A similar analysis of published data for a monodisperse polystyrene indicates that the monodisperse material has a broader distribution of relaxation times and is more nonlinear. The parameter optimization method used appears to be sufficiently sensitive to permit routine characterization of the enthalpy relaxation of amorphous materials.

Journal ArticleDOI
TL;DR: In this article, a glow discharge has been used to promote the reaction between titanium tetrachloride and oxygen in order to deposit thin films of titanium dioxide at low temperatures.
Abstract: An rf glow discharge has been used to promote the reaction between titanium tetrachloride and oxygen in order to deposit thin films of titanium dioxide at low temperatures. Structural properties of the films have been studied as functions of deposition temperature (25 to 700 °C) and of substrate material (Si, sapphire, glass, NaCl, and Ti). Films deposited onto glass substrates were amorphous at temperatures less than 300 °C, anatase at 300 and 400 °C, a mixture of anatase and rutile at 500 °C, and only rutile at 600 °C and above. Films deposited on the other substrates showed similar behavior but the temperatures for specific crystalline forms differed for each substrate material. Deposition at low power densities and 400 °C resulted in large (∼5 μm) anatase crystallites in 1–2 μm films.

Journal ArticleDOI
TL;DR: In this paper, the formation of an amorphous rh-Si alloy film upon thermal annealing at 300 °C was observed, followed by the formation RhSi or a mixture of RhSi and Rh5Si3 around 400
Abstract: Interfacial reaction in bilayers of amorphous Si and crystalline Rh thin films has been studied by transmission electron diffraction and microscopy. In a bilayer of ∼190‐A amorphous Si and ∼60‐A polycrystalline Rh films, we have observed the formation of an amorphous Rh‐Si alloy film upon thermal annealing at 300 °C. The amorphous alloy film crystallizes into the RhSi phase at 400 °C. On the other hand, no amorphous alloy formation was observed upon annealing a bilayer of ∼150‐A amorphous Si and ∼100‐A polycrystalline Rh films; instead, they react at 300 °C to form Rh2Si, followed by the formation of RhSi or a mixture of RhSi and Rh5Si3 around 400 °C.