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Showing papers on "Texture (crystalline) published in 1984"


Journal ArticleDOI
TL;DR: In this paper, the growth of secondary grains with sizes many times larger than the film thickness and with uniform (111) texture was achieved in ultrathin (<100 nm) films of Si on SiO2.
Abstract: Growth of grains with sizes many times (>50×) larger than the film thickness and with uniform (111) texture, has been achieved in ultrathin (<100 nm) films of Si on SiO2. Growth of these secondary grains is driven by minimization of anisotropic surface energy. As a result, the secondary grain growth rate increases with decreasing film thickness. The time required for growth of large secondary grains decreases with increasing temperature.

147 citations


Journal ArticleDOI
TL;DR: In this article, the authors investigated the influence of a preferred crystallographic orientation on mechanical properties of textured Ti-6Al-4V material and found that high cycle fatigue and fatigue crack growth were performed in vacuum, laboratory air, and a 3.5 pct NaCl solution.
Abstract: Tensile properties, high cycle fatigue strength, and fatigue crack propagation behavior were evaluated on highly textured Ti-6Al-4V material to investigate the influence of a preferred crystallographic orientation on mechanical properties. Thermomechanical treatments were used to develop three different textures: a basal, basal/transverse, and transverse type, all of which exhibited the same homogeneously equiaxed microstructure. The Young’s modulus was found to vary between 107 and 126 GNm-2, and yield strength changed from 1055 to 1170 MNm-2. Ductility was only slightly affected by texture. High cycle fatigue and fatigue crack growth measurements were performed in vacuum, laboratory air, and a 3.5 pct NaCl solution. It is shown that laboratory air can be regarded as a quite corrosive environment. In vacuum the highest fatigue strength values were measured whenever loads were perpendicular to basal planes. However, these conditions had the highest susceptibilities to air and 3.5 pct NaCl solution environments. Nearly no influence of texture on fatigue crack propagation was found in vacuum, but in a corrosive environment crack growth parallel to (0002)-planes was much faster than perpendicular to these planes. To explain the corrosive effect on the fatigue properties of the textured material hydrogen is thought to play a key role.

139 citations


Journal ArticleDOI
TL;DR: The iron loss improvement which produces the highest grade of non-oriented Si steel is described on the basis of studies which clarify the effects of Si content, grain diameter, impurities and crystalline texture on the iron loss as mentioned in this paper.
Abstract: The iron loss improvement which produces the highest grade of non-oriented Si steel is described on the basis of studies which clarify the effects of Si content, grain diameter, impurities and crystalline texture on the iron loss. Impurities were found to increase iron loss directly through magnetic domains and indirectly through grain diameter and crystalline texture. The progress of clean steel producing technology resulted in extreme reduction of core loss.

126 citations


Journal ArticleDOI
TL;DR: In this paper, the pyrolysis of triisobutylaluminum, an aluminum alkyl, at temperatures of 220-300 °C onto silicon, SiO2 and device wafer substrates was used to deposit aluminum films conformally in the 2.5 μm windows of a typical device.

77 citations


Journal ArticleDOI
TL;DR: In this paper, the evolution of the texture in two granites and two limestones subjected to slow and uniform temperature change was studied and it was shown that intercrystalline boundaries in granites widen out progressively and porosity increases.

76 citations


Journal ArticleDOI
TL;DR: In this paper, a multilayered film with artificial superstructures was synthesized by alternate deposition of Fe and V in ultrahigh vacuum and X-ray diffraction confirmed the establishment of artificial periodicities with very short wavelengths, e.g. Fe(4 A)-V(8 A) of the minimum case, and bcc [110] texture.
Abstract: Multilayered films with artificial superstructures were synthesized by alternate deposition of Fe and V in ultrahigh vacuum. X-ray diffraction confirmed the establishment of artificial periodicities with very short wavelengths, e.g. Fe(4 A)-V(8 A) of the minimum case, and bcc [110] texture. Magnetic properties as a function of Fe layer thickness were studied from Mossbauer and SQUID measurements. Local magnetization at the Fe interface layer contacting with V is discussed from Mossbauer results on surface-selectively enriched samples and also from polarized neutron diffraction experiments.

67 citations


Journal ArticleDOI
TL;DR: In this paper, the structure of thin ZnO films was investigated by X-ray diffraction and it was found that the preferred orientation in ZnOs is determined in the growth process and that there is a transition region at the interface in which the texture evolves.

56 citations


Journal ArticleDOI
TL;DR: In this article, the evolution of crystallographic texture during plastic deformation was investigated in Zircaloy-2 using X-ray and metallographic techniques, and the resolved fraction of basal poles and the volume fraction of twinned material, were determined as a function of plastic strain for several strain paths and initial textures at 298 K and 623 K.

49 citations


Journal ArticleDOI
TL;DR: In this article, the SiO2 substrate is patterned with a 0.2μm period relief grating, ∼10 nm deep, with approximately square wave profile, many of the secondary grains that form have (100) texture.
Abstract: Solid‐state surface‐energy‐driven grain growth in 30‐nm‐thick Ge films on SiO2, encapsulated with SiO2, produces a predominance of (110) crystallographic texture in secondary grains several micrometers in diameter. If the SiO2 substrate is patterned with a 0.2‐μm period relief grating, ∼10 nm deep, with approximately square‐wave profile, many of the secondary grains that form have (100) texture. These grains show a graphoepitaxial orientation with 〈100〉 directions preferentially parallel to the grating axis.

42 citations


Journal ArticleDOI
TL;DR: In this article, the pore texture of zinc electrodes used in electrochemical batteries has been analyzed and it has been shown that these electrodes are equivalent to cylindrical pore electrodes, and the electrode parameters (radius of pore, pore depth and surface density of pores) have been determined from the values of the electrode capacitance, the electrolyte resistance inside the pores and electrode porosity.

36 citations


Journal ArticleDOI
TL;DR: In this paper, the microstructure and tensile behavior of an Al-3Cu-l.6Li-0.8Mg-1.2Zr alloy, produced by splatquenched powder metallurgy processing, were studied.
Abstract: The microstructure and tensile behavior of an Al-3Cu-l.6Li-0.8Mg-0.2Zr alloy, produced by splatquenched powder metallurgy processing, were studied. The alloy exhibited homogeneous deformation, both in bulk samples and duringin situ TEM studies. This is in contrast to the strain localization that is frequently observed in Mg-free Al-Cu-Li-X alloys. The difference in deformation mode is attributed to a fine distribution of Ś (Al2CuMg) which precipitates up to the grain boundaries. A processing treatment involving 2 pct stretch prior to aging resulted in a yield strength of 555 MPa, a reduction in area of 29 pct, and a strain to fracture of 8.8 pct. This represents an attractive improvement in specific properties compared with 7075-T76 having a similar texture.

Journal ArticleDOI
TL;DR: In this paper, the authors compared pole figure determinations with neutron diffraction and X-ray diffraction on experimentally deformed carbonate rocks, a coarse grained marble and fine grained limestone.

Journal ArticleDOI
TL;DR: In this article, the microstructures of commercial bars of Mo and a Mo alloy have been examined using optical metallography of bar stock, scanning electron microscopy of fracture surfaces, and Auger electron spectroscopy ofin situ fractured samples.
Abstract: The mechanical properties of commercial bars of Mo and a Mo alloy have been investigated. Although longitudinal mechanical properties are good, completely brittle behavior is invariably observed in samples tested in the transverse direction. The microstructures of these materials have been examined using optical metallography of bar stock, scanning electron microscopy of fracture surfaces, and Auger electron spectroscopy ofin situ fractured samples. A number of deleterious microstructural features has been identified; these include a large grain size in the transverse direction as a result of a 〈110〉 fiber texture and fractured carbide-crack stringers on grain boundaries. Oxygen segregation to grain boundaries has been shown not to be a factor contributing to brittle behavior. The origin of the carbides and the development of the associated cracks are described. A thermomechanical processing route, based on a recrystallization and forging procedure, has been developed to manufacture disc-shapes from which components having greatly improved mechanical properties can be produced.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the crystallization behavior of high-density polyethylene blended with polypropylene and found that PE crystallites are aligned with their (110) planes perpendicular to the draw direction of the film specimen.
Abstract: Crystallization behavior of high-density polyethylene blended with polypropylene was investigated in the oriented system, using wide-angle and small-angle x-ray diffractometries and electron microscopy. When polypropylene/polyethylene (PP/PE) drawn blends were heat treated in the temperature range above the melting point of PE, a new orientation texture of PE was produced during melt-recrystallization in the PP matrix. The majority of PE crystallites are aligned with their (110) planes perpendicular to the draw direction of the film specimen. Furthermore, well-developed lamellar structure is formed in the PE phase, along the crystallite b axes oriented preferentially at angles of 30-40° to the draw direction. The reason that such a distinctive orientation texture of PE develops in the blend with PP is discussed in some detail. As a possible explanation, it is suggested that thermal shrinking stress greatly affects the crystallization behavior of PE.

Journal ArticleDOI
TL;DR: In this paper, quelques unes des morphologies representatives vues par observation directe au microscope electronique de nombreuses compositions du copolyester ethylene terephtalate-acide p-hydroxybenzoique and texture specifique biphasique des fibres filees par fusion
Abstract: Description de quelques unes des morphologies representatives vues par observation directe au microscope electronique de nombreuses compositions du copolyester ethylene terephtalate-acide p-hydroxybenzoique et texture specifique biphasique des fibres filees par fusion


Journal ArticleDOI
TL;DR: In this article, the effects of different constituents on core-loss, resistivity and grain size were determined quantitatively using statistical analysis, and the possible mechanisms of the effects are discussed.

Journal ArticleDOI
TL;DR: In this article, X-ray θ-2θ scans showed that the samples had a bcc (110) texture with a strong composition modulation, which is expected for the Bloch spin wave contribution to the magnetization of a 2D ferromagnet.
Abstract: V/Fe composition‐modulated structures have been grown on the (0001) surface of a sapphire substrate in an UHV evaporator. X‐ray θ‐2θ scans showed that the samples had a bcc (110) texture with a strong composition modulation. Samples with three atomic planes of Fe separated by thick layers of V showed a linear temperature dependence of the saturation magnetization over the range 5–400 K. This behavior is expected for the Bloch spin wave contribution to the magnetization of a 2D ferromagnet. Hysteresis measurements also confirmed that the samples were ferromagnetic. Superconductivity has been seen in samples with very thick V layers.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the domain structure and microstructure of high-rate sputtered Co-Cr films by transmission and scanning electron microscopy and found that the form of domain structure is dependent on the degree of c-axis texture in the polycrystalline films, grain size and morphology and the thickness of the film.
Abstract: This paper reports some results of an investigation of the domain structure and microstructure of high-rate sputtered Co-Cr films by transmission and scanning electron microscopy. We find that the form of the domain structure is dependent on (a) the degree of c-axis texture in the polycrystalline films, (b) grain size and morphology and (c) the thickness of the film. The domain structure can vary from a short wavelength ripple or featherlike structure through a stripe domain structure to a form which can be interpreted in terms of discretely magnetised regions of the film. Scanning electron micrographs of cross-sections of the thicker films show that both equiaxed and columnar structures can be obtained. The relationship between the magnetic and micro-structures are discussed in terms of these observations.

Journal ArticleDOI
TL;DR: In this paper, a γc alumina carrier is shown to be hydrated to bayerite or gibbsite in contact with an ammonia solution, or even water, at room temperature, and to boehmite when heated at 410K and a pressure of 0.3 MPa in water.
Abstract: A γc alumina carrier is shown to be partly hydrated to bayerite or gibbsite in contact with an ammonia solution, or even water, at room temperature, and to boehmite when heated at 410K and a pressure of 0.3 MPa in water.

Journal ArticleDOI
TL;DR: In this article, a new formulation of DB in a power series of B2 was developed and the first six interaction energies were calculated from short-range order parameters, and the effective diffusion coefficient at 400°C [as a function of the dispersion relation B2(h)] showed a minimum at a wavelength of about 1.5 nm in contrast with the linear or monotonic behavior of several other systems.
Abstract: Vapor deposited Cu–Ni films were produced containing composition modulations with wavelengths between 0.8 to 5.0 nm. The foils, deposited on mica substrates, exhibited a strong 〈111〉 texture and produced satellite peaks in the x‐ray diffraction patterns. The interdiffusivities in the range of 375–450 °C, which were measured from the decay rate of the x‐ray diffraction satellite intensities, yielded an activation energy of 2.7×105 J/mol. This value is in good agreement with that obtained by tracer diffusivities at high temperatures. The effective diffusion coefficient DB at 400 °C [as a function of the dispersion relation B2(h)] showed a minimum at a wavelength of about 1.5 nm in contrast with the linear or monotonic behavior of several other systems. A new formulation of DB in a power series of B2 was developed and the first six interaction energies were calculated from short‐range order parameters.

Journal ArticleDOI
TL;DR: In this paper, the effects of texture, grain shape and two-phase structure on the changes in anisotropic behaviour of Zr-2.5 wt% Nb pressure tubes are discussed.

Journal ArticleDOI
01 Aug 1984-Fuel
TL;DR: In this paper, the authors compared the gasification of pure and cobalt-doped chars obtained by carbonization of wood sawdust and showed that the catalytic action of cobalt affects both the kinetics of char gasification and the texture of the resulting porous carbons.

Patent
28 Dec 1984
TL;DR: In this paper, an optical data storage medium is disclosed for use in an optical read/write system using an optical wavelength of W, the medium including a textured region having raised areas and depressed areas disposed in a regular array with a period (pitch) not greater than W and a depth (peak-to-trough) in the range 10 to 1,000 nanometers.
Abstract: An optical data storage medium is disclosed for use in an optical read/write system using an optical read wavelength of W, the medium including a textured region having raised areas and depressed areas disposed in a regular array with a period (pitch) not greater than W and a depth (peak-to-trough) in the range 10 to 1,000 nanometers. The medium comprises a substrate and a regular array of zones of magneto-optic material disposed at least over the peaks and troughs of the surface texture and conforming to the surface texture. In many embodiments, there is also a layer or a regular array of zones of an optically reflective material. In one embodiment, the texture is shallow, being generally in the range 10 to 120 nanometers. In a second embodiment, the depth of the texture is at least one tenth of the value of W. In any of the embodiments, there may be a dielectric layer over the top of the structure. The texture can take the form of a grating, or of crossed gratings, or be defined between an array of protuberances; structures with sinusoidal, square-wave (top-hat) or saw-tooth profile are advantageous.

Journal ArticleDOI
TL;DR: In this article, the post-forming room temperature tensile properties in the three principal directions of a strongly textured Ti6Al-4V alloy bar have been determined following uniaxial superplastic deformation at 928°C and dot ϵ I = 4.2 × 10 −4 s −1, over the strain range 0-1.49 (0% −344%).

Journal ArticleDOI
TL;DR: In diffusion-grown layers of compounds with the orthorhombic FeB-and ZrSi2-type structures a pronounced texture is present which is rotationally symmetric with respect to the direction of diffusion as discussed by the authors.
Abstract: In diffusion-grown layers of compounds with the orthorhombic FeB- and ZrSi2-type structures a pronounced texture is present which is rotationally symmetric with respect to the direction of diffusion. In FeB-type structures a [101]-fibre texture is observed for ZrSi and HfSi and a [100]-fan texture for TiSi and ZrGe. In ZrSi2-type compounds the b axis is always perpendicular to the direction of diffusion; different compounds, however, show different textures: a [010]-fan texture for ZrSi2, a [100]-fibre texture for HfSi2 and a 〈101〉-fibre texture for ZrGe2. The textures are explained in terms of preferential diffusion along specific crystallographic directions which can be derived from the crystal structures. At high temperatures a second texture component has been observed in HfSi layers and in layers with the ZrSi2 structure. This second component can be considered as a recrystallization texture and can be derived from the original texture by a rotation of the crystallites of 20–25° around a simple crystallographic direction. The existence of a so-called TiGe phase with the FeB structure in the temperature region 1070–1270 K is questionable. Only Ti6Ge5 has been produced and this compound showed a [001]-fibre texture.

Journal ArticleDOI
TL;DR: In this paper, the velocity dispersion of polarized shear waves is used to separate texture and stress effects by measuring the velocities of the shear wave in polycrystalline quasi-isotropic and textured materials.
Abstract: Non-destructive measurement of stress using ultrasonics often fails because of texture in the analysed material: texture as well as stress influences the wave velocity and reliable methods are needed to separate the two effects. This contribution briefly reviews earlier approaches and presents a new method to separate texture and stress effects by measuring the velocity dispersion of polarized shear waves. The techniques is based upon recently published theoretical work on wave propagation in polycrystalline quasi-isotropic as well as textured materials. Experimental results are in general agreement with the theoretical data.

Journal ArticleDOI
TL;DR: In this article, a planar sample of SmC* liquid crystal helicoidal structure exists in the bulk while the surface layers are unwound, and the connection between these two regions is mediated by line defects, 2π disclinations, responsible for the observed line texture.
Abstract: In a planar sample of SmC* liquid crystal helicoidal structure exists in the bulk while the surface layers are unwound. Connection between these two regions is mediated by line defects, 2π disclinations, responsible for the observed line texture. Thin planar samples may be spontaneously unwound and exist in twisted or uniform configurations. Experiments reveal that helix unwinding in an electric field is a more complex process than considered by previous theories. It involves movement of disclinations and their annihilation, reorientation of molecules in the bulk and domain processes in the surface layer. Ferroelectric-like properties of thin samples have application perspectives.

Patent
17 May 1984
TL;DR: In this article, the authors developed an Al alloy having various excellent characteristics as a part for a magnetic recorder that contacts directly with a magnetic tape by incorporating specific amt. of Si, Cu, Mg, Fe, Mn, Ti, etc.
Abstract: PURPOSE:To develop an Al alloy having various excellent characteristics as a part for a magnetic recorder that contacts directly with a magnetic tape by incorporating specific amt. of Si, Cu, Mg, Fe, Mn, Ti, etc. in Al. CONSTITUTION:Parts for a magnetic recorder, such as a cylinder, stationary or rotary drum for guiding a tape, head drum, etc. for a VTR, that contact directly with a magnetic tape are manufactured of an Al alloy contg. 8.0-10.5% Si, 1.5-4.0% Cu, 0.6-2.0% Mg, 0.1-0.6% Fe, or further >=1 kinds of <0.9% Mn and <0.2% Ti. Primary crystal Si does not exist in the texture of such Al alloy. The average particle sizes of Si in the Al-Si eutectic texture is <=(20-5mum), and the alloy has the texture wherein the particles of the crystallized matter consisting of an intermetallic compd. eutectic compd. or the like are <=(10-3mum) and are dispersed at <=(10-5mum)inter-particle interval. The alloy is resistant to wear and has the characteristics of excellent machineability and a small coeff. of dynamic friction with the tape.

Patent
10 Aug 1984
TL;DR: In this paper, a process for manufacturing thin strip or foil of aluminum of at least 99.9% purity is described, such that after casting, the cast material is rolled to final thickness at temperatures between 20° and 420° C, whereby at thicknesses below at least 8 times the final thickness no intermediate anneals are performed and rolling is carried out at temperatures no higher than 250° C.
Abstract: A process for manufacturing thin strip or foil of aluminum of at least 99.9% purity is such that, after casting, the cast material is rolled to final thickness at temperatures between 20° and 420° C., whereby at thicknesses below at least 8 times the final thickness no intermediate anneals are performed and rolling is carried out at temperatures no higher than 250° C. After a recrystallizing final anneal at temperatures between 480° and 640° C. the material exhibits mainly cube texture.