We report on 27Ai, 65Cu, and 51V spin-echo spectra for the amorphous phase and icosahedral quasicrystal of the Al75Cu15V10 alloy, and 27Al, 65Cu, and 55Mn spin-echo spectra for the icosahedral and crystalline phases of the Al67Cu20Mn13 alloy. The line shape and peak shift reveal different local characteristics among those phases. For the Al75Cu15V10 alloy, peak shifts of all constituent nuclei are more positive in the amorphous phase than in the icosahedral phase, indicating a different s-electron density. For the Al67Cu20Mn13 alloy, an as-quenched icosahedral phase transforms to a crystalline phase by heat treatment. Different peak shifts of 27Al and 55Mn except 65Cu between those phases have been found. It is suggested that there are Mn atoms carrying magnetic moment and that there is no difference in the electronic structure of Cu atoms between those phases.

Thermal conductivity measurements were performed on several amorphous rare earth transition metal thin films of varying microstructure. The thermal conductivity perpendicular to the plane of the film, measured by the thermal comparator method, was compared with the thermal conductivity value measured parallel to the plane of the film. The latter value was obtained by converting electrical conductivity values to thermal conductivity via the Wiedemann–Franz relationship. As expected, the columnar microstructure induced during the sputter deposition of the thin films causes an anisotropy in the thermal conductivity values, with the in-plane values consistently lower than the out-of-plane values. The effect is most pronounced for the more columnar films deposited at higher pressure, for which the in-plane thermal conductivity, 0.3 W/mK, is an order of magnitude lower than the out-of-plane thermal conductivity, 4.3 W/mK. The thermal conductivity out of the plane of the film decreased with increasing deposition pressure, due to the decreasing film density.

Several conductive structures which appeared to be usable as base electrodes in VLSI capacitors based on high dielectric materials have been annealed in oxygen at 650 °C. The studied structures were Pt/TiN, Pt/Ta, Au/TiN, Ru, and RuO2/Ru, prepared under a variety of conditions. The structures have been studied by Rutherford backscattering (RBS) and Auger Electron Spectroscopy (AES). It was found that none of the pure metals, Pt, Au, or Ru, can prevent the diffusion of oxygen to the underlying layer and its oxidation, thus causing a possible break in the electrical conduction path to the silicon substrate. Of the investigated materials, in the thickness range ≤ 110 nm only the RuO2/Ru couple preserved its electrical connectivity to the Si substrate and prevented diffusion of silicon to the surface of the electrode.

Thick films of Bi–Sr–Ca–Cu–O on (100) MgO substrates have been prepared by the screen printing technique with the starting composition of 1112. The annealing process involves a two-step heat treatment. The first-step temperature is chosen between 874 °C and 898 °C for 45 min followed by slow cooling (2 °C/min) to 864 °C. In the second step, the films are kept at 864 °C for a time varying from 0 to 104 h. The Tc (R = 0) and intensity of the characteristic peaks of the high Tc and the low Tc phases in the x-ray diffraction pattern are found to be dependent on the first-step temperature and the duration of the second step. The process of crystallization and the growth of plate-like grains as a function of annealing time at the second step are studied using Scanning Electron Microscopy (SEM). Kinetics of the growth of the high Tc phase has been explained in terms of a reaction mechanism involving the first and second annealing steps.

Flat, hexagonally shaped diamond platelets were observed during the initial stage of microwave plasma assisted deposition of diamond. The platelets are approximately 2.5 μm in linear dimension and are oriented with their large six-sided faces parallel to the silicon substrate. A re-entrant groove, running parallel to the large six-sided face, is present in the small side faces of the platelets. Larger diamond crystals, with a fully developed three-dimensional morphology, all have re-entrant grooves in other directions. The observations support the hypothesis that the growth rate of {111} faceted diamond crystals is greatly enhanced by the presence of microtwins (multiple stacking errors), which give rise to re-entrant corners where they intersect the crystal surface. Fully developed {111} faceting and a strong influence of re-entrant corners is expected when the average lifetime of a carbon atom bonded once to the surface is much less than the average time between addition of adatoms at adjacent surface sites.

Reactions with alumina and platinum crucibles were studied during the preparation of Bi2Sr2Ca1Cu2Oy “2212” glasses. In particular, reactions with Al2O3 are of interest since alumina is a potential substrate material in applications of this superconductor. Glasses processed using alumina crucibles were completely homogeneous and free of secondary phases although the material contained 2.26 at. % Al in solution. After heat treatments, Al was found in the form of SrCaAlOy particles located primarily along grain boundaries of the 2212 superconducting phase. Platinum contamination was minimal (<0.02 at. %) and no Pt-containing secondary phases were found in amorphous or annealed samples. Glasses made with Pt crucibles were found to contain small amounts of CaO, Sr14−xCaxCu24O41, and 2201 as second phases. Differential thermal analysis (DTA) suggested that the crystallization processes were essentially the same for all samples although the small amount of Al seemed to slow the kinetics leading to the formation of 2212. Neither Al nor Pt was detected within the 2212 phase. The measured superconducting compositions in each annealed sample were nearly the same with identical transition temperatures of 88 K. Overall differences in stoichiometry were accommodated by changes in the number and composition of the secondary phases present.

The origin of an anomalous sawtooth-shaped feature in x-ray powder diffraction of solid C60 is explained via electron diffraction analysis. Films sublimed on holey carbon crystallize with close-packed (111) planes parallel to the surface. Rods of diffuse scattering are found along the 〈111〉 axis normal to the surface but not along other 〈111〉 axes. Powder averaging of these rods, coupled with the x-ray form factor of spherical shells with 3.5 Å radius, accounts for the sawtooth feature. We attribute this phenomenon to planar defects parallel to close-packed layers, which form during the growth of solid C60 by sublimation. A possibly related consequence of the growth mode is the observation of strong macroscopic (111) preferred orientation in films sublimed on a variety of substrates.

The environmental embrittlement for the nearly stoichiometric TiAl compound, the microstructure of which consists of monophase γ with equiaxed grains, was evaluated by tensile tests, to determine the effects of the atmospheres used (vacuum, O2 gas, air, and H2 gas) and the testing temperatures (R.T. to 1173 K). At room temperature, the highest elongation and UTS values were observed in the samples tested in vacuum, while the worst values were observed in the samples tested in H2 gas. Transgranular cleavage fracture was dominant and primarily independent of the environmental media. At intermediate temperatures, the samples tested in vacuum exhibited higher elongation and UTS values than those tested in air. Intergranular fracture became more dominant as temperature increased but was insensitive to the environmental media. Based on these results, the mechanism responsible for the observed environmental embrittlement and the implications were discussed.

In this paper, we have demonstrated that very perfect thin multilayers of the Cu/Ni system can be prepared with coherent interfaces if the layer modulation wavelength is in the 10 nm range. At modulation thicknesses above about 60 nm, the interfaces become incoherent. We have injected a crack into a coherent interface in the 10 nm case which has generated dislocations into the interface forming the crack plane, as well as into the layers adjacent to the crack plane. The dislocations injected into the crack plane presumably form misfit dislocations on that interface, and are grouped so close to the crack tip that individual dislocations are not completely imaged. The dislocations injected into the adjacent layers are distributed rather widely. We have analyzed the dislocation emission from a crack in the fcc geometry appropriate to the multilayers using a simplified elastic theory developed for cracks in homogeneous materials. The mixed mode loading which the misfit stresses are expected to produce lead one to expect these materials to be ductile and to have high toughness. Very high dislocation densities on the crack plane near the crack, however, may lead to a brittle mode of failure, which is beyond the purview of the elastic theory. The dislocations are observed to have strong interactions with alternating interfaces in the multilayers, and this effect could be due to elastic bunching of the dislocations at alternating interfaces caused by the misfit stress.

Tensile testing of cast and extruded binary NiAl was performed from 300 to 900 K at strain rates of 1.4 × 10−4 to 1.4 × 10−1 × s−1. The brittle-to-ductile transition temperature (BDTT) was dependent on strain rate, with a three order of magnitude increase in strain rate resulting in approximately a 200 K increase in transition temperature. Regardless of strain rate, at temperatures just above the BDTT the fracture strength increased significantly and the fracture morphology changed from mostly intergranular to predominantly transgranular. It was also determined that the mechanism responsible for the brittle-to-ductile transition in NiAl had an apparent activation energy of approximately 118 kJ/mol. These results support the argument that the mechanism for the brittle-to-ductile transition in NiAl is associated with the onset of a thermally activated deformation process. This process is probably dislocation climb controlled by short circuit diffusion.

Superconducting composite samples were prepared by sintering a mixture of metallic silver and Bi(Pb)–Sr–Ca–Cu–O powder in air. For Ag contents between 0 and ∼15 vol. %, the bulk critical temperature was depressed as much as 40 K, and the relative proportion of the 2223 phase with respect to the 2212 phase was decreased, compared to the pure sample. However, as the Ag content was increased to between 19 and 70 vol. %, critical temperatures above 100 K were measured by transport and ac susceptibility techniques, and the relative proportions of the phases were restored to that of the pure sample. The limit of bulk superconductivity was reached at 73 vol. % Ag where the bulk critical temperature was ∼85 K. For higher Ag contents bulk superconductivity was not observed. Our results also show that sintering in air of silver-clad tapes containing Bi(Pb)–Sr–Ca–Cu–O powder, either by itself or with silver powder, need not be detrimental to the final superconductive properties.

As a possible means of alleviating the severe brittleness in the B2 compounds FeAl and NiAl, the all-electron self-consistent total energy linear muffin-tin orbital (LMTO) method was employed to investigate the possibility of lowering the ⟨111⟩ anti-phase boundary (APB) energies by changing compositions in FeAl and NiAl. For APB's created in the regions with excess Fe (or Ni) atoms, APB energies for the model systems, Fe0.6Al0.4 and Ni0.6Al0.4, were found to be one order of magnitude smaller than those for stoichiometric B2 FeAl and NiAl, respectively. Apparently, the activation of ⟨111⟩ slip became possible in these cases. On the other hand, the APB energies remained at about the same as those in stoichiometric FeAl and NiAl for APB's occurring in regions with equal numbers of Fe (Ni) and Al atoms, implying that the activation of ⟨111⟩ slip in these regions was not eased.

Structural studies on kish graphite (KG) and highly oriented pyrolytic graphite (HOPG) were performed using the techniques of electron channeling pattern (ECP) and electron channeling micrograph (ECM) in the scanning electron microscope. In the KG specimens the ECP for the single crystal was observed for each specimen, while in the HOPG specimens those of polycrystalline graphites with parallel c-axes were observed. The crystal sizes along the a-axis in the HOPG specimens were evaluated by ECM's. The average crystal size was related to a parameter sensitive to their crystallinity, i.e., the ratio of the resistivity at room temperature to that at 4.2 K (residual resistivity ratio). A mapping of the a-axis orientation of HOPG specimens was carried out.

The linewidths of x-ray photoelectron spectra have been correlated with dislocation densities in a shock-damaged crystal of ammonium perchlorate (AP). A centimeter-size AP crystal was loaded at several sites with a diamond pyramid (Vickers) indenter, creating localized strain centers. The crystal was nonuniformly damaged by a rapidly decaying shock (peak pressure of 24.4 kbar at the entry surface), recovered intact, and cleaved through the indentations. The cleaved planes permitted interior analysis of the crystal by x-ray photoelectron spectroscopy (XPS) over a pattern of 1 mm by 1 mm areas. The linewidth of the Cl(2p3/2) spectra ranged from 1.70 eV for the region of greatest visible damage to 1.22 eV for the region of no visible damage, the same linewidth as that obtained for unshocked AP (control). The observed damage was compared to photographs in the literature of gamma-ray irradiated AP crystals, for which dislocation densities were reported. This provided an approximate correlation of dislocation density versus XPS linewidth. The correlation was refined by chemically etching and determining densities on another cleaved plane in the recovered crystal. By this technique, a ∼100X increase in dislocation density was determined for the region of greatest shock damage relative to an unshocked crystal. The strain fields associated with the impressions were found to enhance perchlorate decomposition when driven by shock. Distortion of the molecular lattice in the vicinity of a dislocation is the physical mechanism responsible for the broadening of the photoelectron lines. Ab initio calculations of the Cl(2p) energy level in the perchlorate anion predicted variations of 0.1 to 0.46 eV. Variations of this magnitude are sufficient to produce the observed linewidth broadening.

The adhesion of as-sputtered Pt thin films to NiO single crystals has been characterized by a continuous microscratch technique. In these experiments, a conical indenter was driven into a 1.2 μm thick Pt film at a rate of 15 nm/s, and across the sample surface at a rate of 0.5 μm/s, until a load drop was observed indicating that the film had delaminated. Using the width of the scratch track at the point at which the film delaminated from the substrate, the critical load required for delamination, and the area of the delaminated region, a model has been developed to determine the work of adhesion of the Pt/NiO system. This model uses an elastic contact mechanics approach to relate the stresses acting in a scratch experiment to the strain energy released during film delamination. Using this model, the work of adhesion and hence the interfacial fracture toughness have been determined to be 0.023–0.06 J/m2 and 0.07–0.11 MPa$\sqrt m$, respectively. These values are in reasonable agreement with those determined by other methods for metal-ceramic systems.

Superconducting characteristics and the thermal stability of sputtered, tungsten-based, amorphous thin films are investigated. Electronic properties and crystalline structures are analyzed as a function of the metalloid content in the films. It is well known that the superconducting Tc of a bulk crystalline tungsten is 0.01 K, which is one of the lowest transition temperatures among the superconducting metals. We have found that the W film containing 5 to 70 at. % metalloids exhibits a great enhancement in Tc. In the region of 15 to 35 at. % metalloids, the Tc shows the maximum of 5.0 K, and the transition from normal to superconducting state occurs very sharply. SEM observation together with x-ray diffraction analysis indicates that these films are amorphous in structure. The electrical resistivity is about 150 μΩ-cm, and shows little temperature dependence from Tc to 300 K. In addition, the W–Si amorphous superconductor is thermally very stable after annealing at 700 °C, but the W–Ge amorphous alloy crystallizes at 600 °C.

The oxide films formed on SUS430 stainless steel under various conditions have been investigated by using infrared reflection absorption spectroscopy. A comparison of the spectra of the samples oxidized in moist atmosphere with those oxidized in dry atmosphere shows the important role of water vapor at 873 and 973 K. The abnormally rapid oxidation at 873 K in moist atmosphere with low oxygen pressure is characterized by rapid increasing of the intensity of the absorption band at about 550 cm−1. The frequency of this band shifts to a lower wave number as its intensity increases.

The atmospheric pressure chemical vapor deposition of aluminum nitride coatings from hexakis(dimethylamido)dialuminum, Al2(N(CH3)2)6, and ammonia precursors is reported. The films were characterized by ellipsometry, transmission electron microscopy, x-ray photoelectron spectroscopy, Rutherford backscattering, and forward recoil spectrometry. The films were deposited at 100–500 °C with growth rates up to 1500 Å/min. The films showed good adhesion to silicon, glass, and quartz substrates and were chemically inert. Rutherford backscattering analysis revealed that the N/Al ratio was 1.15 ± 0.05 for films deposited at 100–200 °C and 1.05 ± 0.05 for those deposited at 300–500 °C. Films deposited at 100–200 °C had refractive indexes in the range 1.65–1.80 whereas indexes for films deposited at 300–400 °C were 1.86–2.04. The films were transparent in the visible region. The optical bandgap varied from 5.0 eV for films deposited at 100 °C to 5.77 eV for those deposited at 500 °C. Films deposited at 100–200 °C were amorphous whereas those deposited at 300–500 °C were polycrystalline.

Results of Sneddon's analysis for the elastic contact between a rigid, axisymmetric punch and an elastic half space are used to show that a simple relationship exists among the contact stiffness, the contact area, and the elastic modulus that is not dependent on the geometry of the punch. The generality of the relationship has important implications for the measurement of mechanical properties using load and depth sensing indentation techniques and in the measurement of small contact areas such as those encountered in atomic force microscopy.

We have measured stress variations with temperature as a function of film thickness and a given grain size in pure Al and Al–0.5% Cu films on Si substrates. The variation in thickness for a given grain size is brought about by using the same film and the repeated controlled growth and dissolution of a barrier anodic oxide which can be grown uniformly on the film. Stress measurements were made as a function of temperature by measuring wafer curvature after successively removing each 0.1 μm of Al film. The components of strengthening due to the film thickness and the presence of grain boundaries were separated by assuming that the flow stress of the film is simply the sum of these two components. It is found that strengthening due to film thickness varies inversely with the thickness, which is consistent with results obtained by us using laser-reflowed films in an earlier work. The Hall–Petch coefficients calculated from the strengthening due to the grain boundaries are slightly higher than those reported for bulk Al. However, it is also recognized that the variation of the flow stress as g−1, where g is the grain size, is more plausible than that predicted by the Hall–Petch relation (i.e., as g−1/2). The variations of these two components with temperature, and under tension and compression, are discussed.