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Showing papers on "Texture (crystalline) published in 1989"


Journal ArticleDOI
TL;DR: In this paper, the surface morphology of the diamond films was a function of position on the sample surface and the methane concentration in the feedgas, which was determined to be similar to natural diamond in terms of composition, structure, and bonding.
Abstract: Thin carbon films grown from a low pressure methane-hydrogen gas mixture by microwave plasma enhanced CVD have been examined by Auger electron spectroscopy, secondary ion mass spectrometry, electron and x-ray diffraction, electron energy loss spectroscopy, and electron microscopy. They were determined to be similar to natural diamond in terms of composition, structure, and bonding. The surface morphology of the diamond films was a function of position on the sample surface and the methane concentration in the feedgas. Well-faceted diamond crystals were observed near the center of the sample whereas a less faceted, cauliflower texture was observed near the edge of the sample, presumably due to variations in temperature across the surface of the sample. Regarding methane concentration effects, threefold {111} faceted diamond crystals were predominant on a film grown at 0.3% CH4 in H2 while fourfold {100} facets were observed on films grown in 1.0% and 2.0% CH4 in H2. Transmission electron microscopy of the diamond films has shown that the majority of diamond crystals have a very high defect density comprised of {111} twins, {111} stacking faults, and dislocations. In addition, cross-sectional TEM has revealed a 50 A epitaxial layer of β3–SiC at the diamond-silicon interface of a film grown with 0.3% CH4 in H2 while no such layer was observed on a diamond film grown in 2.0% CH4 in H2.

232 citations


Journal ArticleDOI
TL;DR: The texture of vapour deposits changes from the orientation that places the lowest energy crystal facets parallel to the substrate under the condition of low atom or ion concentration adjacent to the deposit, to the orientation which places the higher energy crystal facet parallel to a substrate as the atom or ions adjacent to a deposit increases as discussed by the authors.
Abstract: The texture of vapour deposits changes from the orientation that places the lowest energy crystal facets parallel to the substrate under the condition of low atom or ion concentration adjacent to the deposit, to the orientation that places the higher energy crystal facets parallel to the substrate as the atom or ion concentration adjacent to the deposit increases.

110 citations


Journal ArticleDOI
TL;DR: In this article, the influence of grain orientation and weak link coupling between grains on the critical current of polycrystalline Y•Ba•Cu•O superconductors has been investigated by numerical methods.
Abstract: The influence of grain orientation and weak‐link coupling between grains on the critical current of polycrystalline Y‐Ba‐Cu‐O superconductors has been investigated by numerical methods. The theoretical results indicate that there is size effect on jC in bulk polycrystals, and that it is not necessary to consider the influence of grain orientation when jC is less than 105 A/cm2.

81 citations


Journal ArticleDOI
TL;DR: In this paper, linear equations were developed for converting electromagnetic induction readings (ECa) from EM38 meters to saturated paste electrical conductivity values (ECc) to correlate EM38 readings with mea...
Abstract: Linear equations were developed for converting electromagnetic induction readings (ECa) from EM38 meters to saturated paste electrical conductivity values (ECc). To correlate EM38 readings with mea...

78 citations


Journal ArticleDOI
TL;DR: In this paper, it was shown that thin films of copper deposited on the (1120) plane of sapphire disintegrated into clusters when annealed at 650°C under nonoxidizing conditions.

75 citations


Journal ArticleDOI
TL;DR: In this paper, the textural and structural changes of polycrystalline diamond films have been studied by reactive plasma etching, electron microscopy, Raman spectroscopy and density measurement.
Abstract: Polycrystalline diamond films have been prepared by plasma-assisted chemical vapor deposition (CVD) from gaseous mixtures of various methane/ hydrogen ratio. The textural and structural changes of the films have been studied by reactive plasma etching, electron microscopy, Raman spectroscopy and density measurement. Changes in elastic constant and thermal conductivity are briefly reviewed. Single crystals of size 100μm with good crystalline quality were prepared, while the polycrystalline films grown under the same condition proved to be defective. Finally, it is suggested that the defects characteristic of CVD diamonds may be caused by double bonds of various forms.

68 citations


Journal ArticleDOI
TL;DR: In this paper, the authors measured the partial pressures of the argon and nitrogen gases measured through the target show an apparent drop as power is applied to the titanium target, which is actually a density reduction of the gases in front of the target due to gas rarefaction and heating.

65 citations


Journal ArticleDOI
TL;DR: In this paper, the authors compared ultrasonic and X-ray predictions of the orientation distribution coefficients (ODC) of polycrystals for thin plates of cubic crystallites for which the texture information is deduced from the velocity anisotropy of guided modes.
Abstract: Ultrasonic techniques for determining the orientation distribution coefficients (ODC’s), which define the preferred orientation of polycrystals, are discussed. The theory is reviewed for thin plates of cubic crystallites for which the texture information is deduced from the velocity anisotropy of guided modes. Experimental ultrasonic and X-ray predictions of the ODC’s of up to an order of 4 are compared for plates of commercially pure electrolytic tough pitch (ETP) copper and aluminum. ForW 420 andW 440 in both samples andW 400 in copper, the predictions agree to |ΔW|∼10-3. However, considerably greater differences are reported for the predictions ofW 400 in aluminum. Interpretation of these comparisons is assisted by a detailed error analysis for the ultrasonic technique and reference to a number of other recent comparisons of ultrasonic and neutron or X-ray predictions of ODC’s Possible applications of the ultrasonic technique during the production and forming of metal sheet are indicated.

64 citations


Journal ArticleDOI
TL;DR: In this paper, the influence of the presence or absence of HCl during gate oxidation at 1100 and 1150°C on the electrical and structural properties of polycrystalline silicon thin-film transistors was investigated.
Abstract: The influence of the presence or absence of HCl during gate oxidation at 1100 and 1150 °C on the electrical and structural properties of polycrystalline silicon thin‐film transistors was investigated. Devices processed without HCl exhibited a lower leakage current, a larger current switching ratio, a 25%–55% increase in carrier mobility, and a 21%–30% lower grain‐boundary trap density. Materials investigation showed that the improvement was not primarily due to an increase in grain size, which was about 1000 A irrespective of processing conditions, but to a change in crystallite orientation. X‐ray diffraction measurements showed an increased {110} texture in devices processed without HCl. In addition, in the latter devices, dopant diffusion under the gate from the source and drain contacts was reduced by 7.6% to 12%. A linear relationship was observed between the average grain‐boundary trap density and the average lateral dopant diffusion length. These findings are explained by considering the point defect chemistry and its relationship to grain‐boundary mobility. Removal of HCl from the oxidation ambient increases the concentration of silicon self‐interstitials. The increased migration of these point defects to grain boundaries enhances their nonconservative motion and therefore increases grain‐boundary mobility. This in turn, allows the boundary to more completely acquire a lower‐energy configuration. This lower‐energy configuration of the boundary contains a minimum of broken bonds and therefore minimizes both the grain‐boundary electrical activity and the diffusion along grain boundaries.

64 citations



Journal ArticleDOI
TL;DR: In this article, the Campbell method was used to measure anisotropy and hysteresis in transport critical currents with changing temperature and polarity of magnetic field in sintered Ln-Y-Ba-Cu-O superconductors.

Journal ArticleDOI
TL;DR: In this article, the effects of texture on the deformation behavior of glassy polymers were investigated using a physically-based constitutive model of Boyce, Parks, and Argon describing the rate, temperature, and pressure dependent inelastic deformation of initially isotropic polymers.

Journal ArticleDOI
TL;DR: The N 2 partial pressure, target power and substrate bias potential all have a significant effect on the hardness and crystallographic orientation of TiN coatings prepared by high-rate reactive sputtering on carbide substrates.
Abstract: The N 2 partial pressure, target power and substrate bias potential all have a significant effect on the hardness and crystallographic orientation of TiN coatings prepared by high-rate reactive sputtering on cemented carbide substrates Variations in both the substrate bias potential and the target power had a strong affect on the hardness and texture of the TiN coatings Vickers microhardness values (50gf) of the TiN coatings varied between 970 and 3290 kgf mm -2 as the bias was stepped between 0 and –200 V and the target power between 23 and 100kW The texture coefficient of the TiN coatings with a constant –100 V bias was strongly (111) at the low power level of 23 kW, but the texture became random as the power was increased to 40 kW and above with the same –100 V bias At a fixed power level of 10 kW, the orientation of the TiN coatings changed from (111) at zero bias to (200) between –20 and –100 V, to strongly (220) at –150 and –200 V The hardness of TiN coatings with N/Ti ratios of 070 - 101 produced by varying the N 2 partial pressure during deposition had a narrow range between 3140 and 3400 kgf mm -2 , but the texture coefficient varied from random to strongly (220) the adhesion of the TiN coatings was measured with the scratch test, and a critical load of 80 ± 05 kgf was the same for all samples except for the ones at the lowest target power (23 kW), low biases (0 and –20 V) and the lowest N/Ti ratio (070)

Journal ArticleDOI
TL;DR: The use of BaCuO 2 as a solvent to aid the texturing process is discussed in this paper, where magnetization measurements show a large increase in hysteresis at 77 K compared to unaligned polycrystalline YBa 2 Cu 3 O 6+ x.
Abstract: Zone melting has been used to produce texture in bulk YBa 2 Cu 3 O 6+ x . By controlling the directional solidification of the molten zone, oriented structures are produced that consist of domains of aligned grains, with some misalignment between domains. Scanning electron microscopy and optical microscopy show a high degree of texture produced by this technique. Magnetization measurements show a large increase in hysteresis at 77 K compared to unaligned polycrystalline YBa 2 Cu 3 O 6+ x . The use of BaCuO 2 as a solvent to aid the texturing process is discussed.

Journal ArticleDOI
TL;DR: In this article, a planar dc magnetron sputtering was used for the deposition of thin Y1Ba2Cu3O7−δ films on single-crystal LiNbO3 substrates.
Abstract: We present details about the deposition of thin Y1Ba2Cu3O7−δ films on single‐crystal LiNbO3 substrates by planar dc magnetron sputtering. Among other data, results of transition temperature (Tc(R=0) =88 K) and critical current density (jc >2×109 A/m2 at 77 K) plus some details about film‐to‐substrate orientation which is present in all three crystallographic directions are reported.

Journal ArticleDOI
TL;DR: A technique has been developed to grow (111) textured diamond films on smooth substrates using attached diamond seeds as mentioned in this paper, where the degree of texture is defined by the initial texture of the seeds.
Abstract: A technique has been developed to grow (111) textured diamond films on smooth substrates using attached diamond seeds. The degree of texture is defined by the initial texture of the seeds. This initial texture depends upon the seed size and the cleaning procedure. Under the best conditions, over 90% of the seeds exhibit a (111) texture with a tip angle of less than 0.25°. Further growth of diamond on these seeds does not affect the texture, and diamond films obtained by such growth are expected to have smoother surfaces and more controlled doping than nontextured polycrystalline films.

Patent
16 Aug 1989
TL;DR: Enhanced crystallographic texture is developed in an alpha or alpha-beta titanium alloy having a dispersion of particles therein, by heating the alloy to essentially the all beta phase range and mechanically hot working the alloy in this range as mentioned in this paper.
Abstract: Enhanced crystallographic texture is developed in an alpha or alpha-beta titanium alloy having a dispersion of particles therein, by heating the alloy to essentially the all beta phase range and mechanically hot working the alloy in this range. The mechanical working is preferably accomplished by extrusion, rolling, or forging. The particles are stable during working, and prevent the formation of random texture in recrystallized beta phase grains at the working temperature. The particles are preferably oxides formed from rare earth elements such as erbium or yttrium, that are introduced into the alloy during manufacture. The alloys processed according to the invention are preferably prepared by powder metallurgy to achieve a uniform microstructure prior to working. A particularly suitable alpha-beta (but near alpha) titanium alloy contains aluminum, zirconium, hafnium, tin, columbium, molybdenum, tungsten, ruthenium, germanium, silicon, and erbium.

Journal ArticleDOI
TL;DR: In this paper, an ion beam milling at grazing angles of a 2400-A-thick, c-axis-oriented YBa2Cu3O7 film is shown to give smooth films which superconduct at thicknesses on the order of tens of angstroms.
Abstract: Successive ion beam milling at grazing angles of a 2400‐A‐thick, c‐axis‐oriented YBa2Cu3O7 film is shown to give smooth films which superconduct at thicknesses on the order of tens of angstroms. The thinning and polishing process is characterized at successive milling stages using resistance transitions, x‐ray analysis, scanning electron microscopy, and Rutherford backscattering and channeling analysis of composition and surface quality. As thinning proceeds, scanning electron microscopy and diffraction features associated with a‐axis texture are removed and crystalline quality, as measured by x rays and channeling, markedly improves.

Journal ArticleDOI
TL;DR: In this paper, the concept of fractal dimension has been applied to analysis of surface roughness, and practical examples are given for surface profiles of stainless steel with various surface finishes.

Journal ArticleDOI
TL;DR: The dependence of magnetic properties and microstructure of a sputtered thin film medium for high-density longitudinal recording on a Cr underlayer and circumferential substrate texture has been studied in this article.

Journal ArticleDOI
TL;DR: In this paper, it was argued that the strong crystal orientation is due to both directional solidification in a thermal gradient and uniaxial deformation of the solid phase in the twin rollers.
Abstract: Rapid solidification by twin‐roller quenching of iron‐neodymium‐boron alloys produces flakes which show a strong (00l) texture normal to their surface by x‐ray diffraction. The strong crystal orientation is argued to be due to both directional solidification in a thermal gradient and uniaxial deformation of the solid phase in the twin rollers. Magnetization studies on individual flakes show intrinsic coercivities of 14 kOe and a nearly 50% higher remanance for field normal to the flake surface (Br =9.5 kG) than in the flake plane (Br =6.5 kG). The perpendicular (BH)max is 16 MG Oe.

Journal ArticleDOI
TL;DR: The authors found that thin films of polycrystalline zirconia, deposited on a sapphire substrate become gradually discontinuous when annealed at high temperature, and proposed an approximate criterion for cavity nucleation that depends on the interfacial energies.

Journal ArticleDOI
TL;DR: In this paper, electron diffraction measurements reveal an implantation-induced texture of titanium nitride precipitations and support the assumption that the effect of implantationinduced texture is caused by the process of seed selection through ion channeling.
Abstract: High-fluence nitrogen ion implantation into titanium at room temperature results in the formation of titanium nitride precipitation. Electron diffraction measurements reveal an implantation-induced texture of titanium nitride precipitations. Electron diffraction diagrams were taken while tilting the implanted samples and incomplete pole figures were determined. The measured pole figures show a fibre texture. The reproduction of the orientation distribution function based on a tomographic algorithm. The experiments demonstrate a strong coupling effect of implantation-induced texture on direction of implantation. The most intensive texture component, the (111) plane, is always perpendicular to the direction of implantation. Results of this investigation support the assumption that the effect of implantation-induced texture is caused by the process of seed selection through ion channeling.

Patent
18 Dec 1989
TL;DR: A magnetic disk as mentioned in this paper is a disk in which a texture is formed in a first region spaced apart from an opening formed by a glass substrate by a predetermined distance, and a lubricant is coated on only the texture.
Abstract: A magnetic disk in which a texture is formed in a first region spaced apart from an opening formed in a glass substrate by a predetermined distance, and a lubricant is coated on only the texture. The texture is not formed in a second region serving as a data surface, and an undercoating film, a magnetic recording film, and a protective film are sequentially coated on the surface of the glass substrate. In this magnetic disk, a floating amount of a magnetic head can be set to be small, and high-density data can be recorded. The data surface can be free from contamination by dust.

Journal ArticleDOI
TL;DR: In this article, the onset of the resistive transition was 85 K, while zero resistance was obtained at 50 K. The films resulted highly textured with the c axis perpendicular to the substrate surface.
Abstract: Films of Bi2Sr2CaCu2O8+x have been grown from KCl solution. Gadolinium gallium garnet substrates (1 1 1) oriented have been used. The films resulted highly textured with the c axis perpendicular to the substrate surface. The onset of the resistive transition was 85 K, while zero resistance was obtained at 50 K. This technique is particularly promising in view of the possibility to grow large epitaxial films of both the Bi2Sr2CaCu2O8+x and the Bi2Sr2Ca2Cu3O10+x phases.

Journal ArticleDOI
TL;DR: In this paper, the crack growth resistance of a textured, extruded alumina body was compared with that of anisotropic, isopressed body of similar grain size, density, and chemistry.
Abstract: The crack growth resistance of a textured, extruded alumina body was compared with that of anisotropic, isopressed body of similar grain size, density, and chemistry. R-curve levels reflected the preferred orientation; however, R-curve slopes were the same in all instances, implying a similar crack growth-resistive mechanism. Three orthogonal orientations of crack growth in the two structures exhibited similar forms of K(IR) versus Delta-a curves, for which a schematic diagram for polycrystalline ceramics is proposed.

Journal ArticleDOI
TL;DR: In this article, ScPc2 thin films were deposited by vacuum sublimation at a pressure of ca. 10−6 Torr onto substrates either at room temperature or heated above 370K.

Journal ArticleDOI
TL;DR: In this article, the preferred crystallographic orientation or texture of aluminum films deposited on oxidized silicon by evaporation and by partially ionized beam (PIB) deposition is studied.
Abstract: The preferred crystallographic orientation, or texture, of aluminum films deposited on oxidized silicon by evaporation and by partially ionized beam (PIB) deposition is studied. Texture is quantified by the x‐ray diffraction pole figure technique. The pole figures reveal important details of the crystallite distribution not quantifiable by simply taking the 2θ scan. It is found that the films deposited by the PIB technique possess a very strong {111} fiber texture whose strength can be controlled by deposition conditions. Correlation between the strength of the texture and the electromigration lifetime is discussed.

Journal ArticleDOI
TL;DR: The pore size and surface area of aluminas has been found to be affected significantly by conditions of precipitation and ageing, largely due to the interconversion of amorphous hydroxide, pseudoboehmite and bayerite as mentioned in this paper.

Journal ArticleDOI
TL;DR: In this paper, the effect of texture on the flow stress of polycrystalline copper (99.999 pct) was determined by neutron diffraction, as were the deformation textures.
Abstract: Polycrystalline copper (99.999 pct) having four different grain sizes (from 4 to 220 μm) was strained in tension at room temperature to true plastic strains of 0.05, 0.10, 0.20, and 0.30. The initial texture of the materials was determined by neutron diffraction, as were the deformation textures. Both inverse pole figures and calculated TaylorM factors were then derived from the data. In general, it was observed that the texture strengthens at increasing strain and that the effect of grain size on this development is not very pronounced. The measured change in the volume concentration of the (111) texture component was compared to that obtained from a model simulation, and in general, the experiments and the simulations agreed well. The effect on the flow stress of the initial texture, and on the texture which develops during straining, could be accounted for on the basis of TaylorM factors calculated from the experimental results, and it was found that there is an effect of texture on the flow stress. The flow stress at strains above yield, expressed as a modified Hall-Petch relationship, was not greatly affected by corrections toM induced by strain and grain size.