Showing papers on "Texture (crystalline) published in 1996"
TL;DR: Deposited conductors made using this technique offer a potential route for the fabrication of long lengths of high‐Jc wire capable of carrying high currents in high magnetic fields and at elevated temperatures.
Abstract: A method to obtain long lengths of flexible, biaxially oriented substrates with smooth, chemically compatible surfaces for epitaxial growth of high‐temperature superconductors is reported. The technique uses well established, industrially scalable, thermomechanical processes to impart a strong biaxial texture to a base metal. This is followed by vapor deposition of epitaxial buffer layers (metal and/or ceramic) to yield chemically compatible surfaces. Epitaxial YBa2Cu3Ox films grown on such substrates have critical current densities exceeding 105 A/cm2 at 77 K in zero field and have field dependencies similar to epitaxial films on single crystal ceramic substrates. Deposited conductors made using this technique offer a potential route for the fabrication of long lengths of high‐Jc wire capable of carrying high currents in high magnetic fields and at elevated temperatures.
902 citations
Journal Article•
TL;DR: In this article, a method to obtain long lengths of flexible, biaxially oriented substrates with smooth, chemically compatible surfaces for epitaxial growth of high-temperature superconductors is reported.
Abstract: A method to obtain long lengths of flexible, biaxially oriented substrates with smooth, chemically compatible surfaces for epitaxial growth of high‐temperature superconductors is reported. The technique uses well established, industrially scalable, thermomechanical processes to impart a strong biaxial texture to a base metal. This is followed by vapor deposition of epitaxial buffer layers (metal and/or ceramic) to yield chemically compatible surfaces. Epitaxial YBa2Cu3Ox films grown on such substrates have critical current densities exceeding 105 A/cm2 at 77 K in zero field and have field dependencies similar to epitaxial films on single crystal ceramic substrates. Deposited conductors made using this technique offer a potential route for the fabrication of long lengths of high‐Jc wire capable of carrying high currents in high magnetic fields and at elevated temperatures.
854 citations
TL;DR: In this paper, the authors measured the intrinsic force per unit width (F/w) in the film during and after deposition from the change in substrate curvature measured in situ by a laser scanning technique.
Abstract: Copper and silver single layer and multilayered thin films were thermal vapor deposited onto cantilevered substrates [Si(100) with native oxide] near room temperature in ultrahigh vacuum. The total force per unit width (F/w) in the film during and after deposition was determined from the change in substrate curvature measured in situ by a laser scanning technique. The intrinsic component of F/w was obtained by subtraction of the thermal component, which was obtained by measuring the product of the biaxial modulus of the film (Yf) and the difference in coefficients of thermal expansion of the substrate and the film (Δαs−f) while each sample was still in the ultra‐high vacuum deposition chamber. For all samples, the measured value of YfΔαs−f was substantially lower than the calculated value based on the {111} biaxial modulus and the coefficients of thermal expansion of the bulk materials, even though x‐ray diffraction indicated strong {111} film texture. During deposition, a general trend in F/w was found r...
215 citations
Patent•
10 Apr 1996TL;DR: A biaxially textured article is a rolled and annealed, bao-textured substrate of a metal having a face-centered cubic or hexagonal close-packed crystalline structure; and an epitaxial superconductor or other device epitaxially deposited thereon as discussed by the authors.
Abstract: A biaxially textured article includes a rolled and annealed, biaxially textured substrate of a metal having a face-centered cubic, body-centered cubic, or hexagonal close-packed crystalline structure; and an epitaxial superconductor or other device epitaxially deposited thereon.
164 citations
TL;DR: In this article, the authors describe the fabrication of epitaxial, high-J c, biaxially aligned YBCO thick films on rolling-assisted bao-textured substrates (RABiTS).
137 citations
TL;DR: In this article, the thickness dependence of film structure and the dielectric, ferroelectric, and piezoelectric properties have been characterized over the thickness range of 1-12 μm.
Abstract: Thick films of lead zirconate titanate of the morphotropic phase boundary composition, Pb(Zr0.52Ti0.48)O3, have been fabricated on platinum-buffered silicon using a modified sol–gel spin-coating technique. Crack-free films of 12-μm thickness can be uniformly deposited on 3-in.-diameter wafers with high yield and properties comparable to those of bulk ceramics. The thickness dependence of film structure and the dielectric, ferroelectric, and piezoelectric properties have been characterized over the thickness range of 1–12 μm. A strong (100) texture develops as film thickness increases above 5 μm; the films were marked by saturation values of longitudinal piezoelectric coefficient d33, 340 pC/N; remanent polarization, 27 μC/cm2; and dielectric permittivity, 1450. PZT films in this thickness range are extremely well-suited to application as electromechanical transduction media in silicon-based microelectromechanical systems (MEMS).
134 citations
TL;DR: In this article, the structure and morphology of the layers were made via XRD and SEM techniques, respectively, and the hardness was determined by nanoindentation, and residual stresses were derived from the bending of the coated substrates.
Abstract: Alumina coatings were reactively deposited on steel substrates by pulsed magnetron sputtering at substrate temperatures (Ts) of 330–760 °C. Investigations into the structure and morphology of the layers were made via XRD and SEM techniques, respectively. As to the layer properties, the hardness was determined by nanoindentation, and the residual stresses were derived from the bending of the coated substrates. At substrate temperatures of less than 330 °C the Al2O3 layers are amorphous to X-rays, whereas γ-Al2O3 is detected at a substrate temperature Ts ≈ 480 °C. A further increase in substrate temperature to 560 °C results in the formation of a pronounced texture of γ-Al2O3. A phase mixture of textured γ- and α-Al2O3 is deposited at Ts ≈ 690 °C. At Ts ≈ 760 °C the layer consists completely of α-Al2O3 with crystallite sizes of about 1 μm. The occurrence of the crystalline γ phase at 480 °C is linked with a pronounced increase in hardness from 10 to 19 GPa. The layer hardness of pure α-Al2O3 amounts to 22 GPa and corresponds to the hardness of the bulk material.
131 citations
TL;DR: In this article, a computer simulation of grain growth in two dimensions has been used to model microstructural evolution in Ag (001)Ni thin films, and two orientation dependent driving forces have been included in the simulation: surface and interface energy and strain energy.
129 citations
TL;DR: In this paper, it was shown that the addition of a small amount of nitrogen greatly enhances the growth rate of the {100} faces, making the fastest growth direction in comparison with the 〈100 ǫ and ͡ 111 ͞ directions.
Abstract: Localized {100} fiber textured diamond films were grown by addition of 20–200 ppm nitrogen into the gas phase during hot‐filament chemical‐vapor deposition (CVD). Cathodoluminescence indicates the presence of the nitrogen‐vacancy system in the {100} textured diamond, whereas a blue ‘‘band A’’ luminescence is normally observed in diamond films grown without nitrogen addition. The results demonstrate that the nature of the substrates used for growth has no appreciable influence on the {100} texture, which implies that this fiber texture is obtained by competitive growth and selection of facets. The interaction of nitrogen with the {100} surface is a highly important factor in this process. Homoepitaxial growth shows that the addition of a small amount of nitrogen greatly enhances the growth rate of the {100} faces, making 〈100〉 the fastest growth direction in comparison with the 〈110〉 and 〈111〉 directions. This is attributed to breaking of a part of the dimers on the (2×1) reconstructed {100} surface by nitrogen compounds. The {100} texture in narrow, ring‐shaped areas on diamond layers grown by the flame technique can also be attributed to the occurrence of a certain amount of nitrogen in the gas phase. It is demonstrated that the flame grown polycrystalline diamond layers have morphologies and cathodoluminescence features that are consistent with those observed in the hot‐filament CVD diamond films grown with the addition of nitrogen.
128 citations
TL;DR: In this paper, a detailed investigation of the origin of the cube texture component during hot rolling has been performed by applying the electron back scattering pattern (EBSP) technique in SEM.
120 citations
TL;DR: Indium doped ZnO thin films have been prepared on heated Corning 7059 glass by the pyrosol spray method as discussed by the authors, showing that indium doping has an important role in grain growth at high substrate temperature.
TL;DR: In this article, the microstructure, micro-and macrotexture and grain boundary distributions, which had been generated by severe plastic deformation (using the equi-channel angular technique) were studied.
TL;DR: In this article, the macro and microscopic structure of mesophase pitch-based carbon fibers of typical textures is observed using optical, scanning electron, transmission electron, and scanning tunneling microscopes, and the unique pleat shaped structural units, which are aligned in a zigzag manner in the longitudinal section of the carbon and graphitized fibers, were found by high resolution SEM and STM.
TL;DR: In this article, the shape-recoverable tensile strain from a measured texture by estimating volume fractions of correspondence-variants for each oriented grain was calculated as a function of the angle to the rolling direction from a crystallite orientation distribution function.
TL;DR: In this article, a viscoplastic model is presented for distributing the deformation applied to a polycrystal in a non-uniform fashion among the constituent crystals through an appropriately defined local neighborhood.
TL;DR: In this article, the authors investigated the structural changes of ZnO thin films by rf-magnetron sputtering with changing deposition parameters and found that the microstructure was altered from a smooth fine columnar structure to abnormally grown elongated crystallites.
Abstract: Crystallographic orientation and microstructural changes of ZnO thin films deposited by rf‐magnetron sputtering were investigated with changing deposition parameters. Positional dependence of texture orientation and microstructural features, which might be attributed primarily to bombardment of high energetic oxygen species on the film in the region of the target erosion area, were observed. The films deposited at low temperature and/or using pure argon had (002) preferred orientation and a smooth columnar structure. At increasing substrate temperature and/or oxygen partial pressure, c‐axis orientation of the film was severely degraded and abnormal elongated crystallites were also developed. As the films became thicker, c‐axis orientation changed from normal to the substrate to parallel to the substrate. In this case, the microstructure was altered from a smooth fine columnar structure to abnormally grown elongated crystallites that were developed to a faceted texture structure.
TL;DR: In this paper, the effects of microstructure on electromigration behavior were evaluated in three nominally 1 μm thick pure aluminum films, which were tested at temperatures from 423 to 523 K. The three Al films had essentially the same grain structure but different variants of an 〈111〉 texture.
Abstract: The effects of microstructure on electromigration behavior were evaluated in three nominally 1 μm thick pure aluminum films, which were tested at temperatures from 423 to 523 K. The three Al films had essentially the same grain structure but different variants of an 〈111〉 texture. Texture had a very strong effect on the electromigration behavior in ∼2 μm wide polycrystalline lines, where both a reduced fraction of randomly oriented grains and a tighter 〈111〉 distribution increased the electromigration lifetime. The apparent activation energy for electromigration decreased as the texture strengthened. The near bamboo microstructure of 0.5 μm narrow lines showed extensive orientation clustering with an unusually high proportion of low angle boundaries in the most strongly 〈111〉 textured film. The electromigration damage in both 2 and 0.5 μm wide lines was correlated with the types of flux divergence sites in each film. The texture impacts the character of the grain boundaries and interfaces which control th...
TL;DR: In this article, the effects of surface pretreatment and substrate conditions on residual stress of diamond films were systematically investigated by scanning electron microscopy, X-ray diffraction, Raman and indentation adhesion testing.
TL;DR: In this paper, the residual stress state in both the cementite and ferrite phases of cold-drawn pearlitic wires has been measured by neutron diffraction, and the phase microstress in the axial direction is obtained.
TL;DR: In this paper, the authors found that the initial polarization state of as-grown PLZT thin-film capacitors is an important indicator to determine further imprint behavior, and they further found that epitaxial, oriented, and polycrystalline capacitors exhibited weak polarization and little dependence of the initial prepolarization state on the oxygen cooling pressure.
Abstract: (Pb,La)(Zr,Ti)O3 (PLZT) thin films with various crystalline qualities, i.e., epitaxial, oriented, and polycrystalline, have been grow. These PLZT thin films cooled at various oxygen cooling pressures were found to have different asymmetric switching and imprint behaviors, depending on the crystalline quality of the PLZT thin films. It was found that the initial polarization state of as‐grown PLZT thin films is an important indicator to determine further imprint behavior. Epitaxial PLZT thin‐film capacitors were prepolarized in an as‐grown state and further exhibited the large dependence of asymmetric switching and imprint behavior on the oxygen cooling pressure. On the other hand, oriented or polycrystalline PLZT capacitors exhibited very weak polarization and little dependence of the initial prepolarization state on the oxygen cooling pressure. Consequently, the PLZT capacitors containing polycrystalline nature had a strong resistance to the imprint failure.
TL;DR: In this paper, the effects of low-temperature processing on texture development were investigated. And the profound influence of low temperature processing steps, hitherto assumed benign from the viewpoint of texture development, was reported.
Abstract: The profound influence of low-temperature processing steps, hitherto assumed benign from the viewpoint of texture development, is reported. On inclusion of a 400°C step and further heat treatment at 700°C, PZT (40/60) sol-gel thin films with a strong (111) texture were obtained. When the 400°C step was excluded, the films exhibited a strong (100) texture. The (111) PZT texture development is nucleation-controlled and is attributed to the solid-phase epitaxial effect. The (100) texture is considered growth-controlled in that (100) oriented grains grow preferentially so as to minimize surface energy.
TL;DR: In this paper, the properties of polycrystalline textured diamond films with the purpose of determining the parameters responsible for the texture, growth rate, and surface morphology were investigated.
Patent•
18 Oct 1996
TL;DR: A method of manufacturing a magnetic disk includes the steps of depositing a sublayer, a Cr layer and a Co-based magnetic layer on a substrate as discussed by the authors, which causes the Cr crystals to avoid growing with a predominantly (200) orientation.
Abstract: A method of manufacturing a magnetic disk includes the steps of depositing a sublayer, a Cr layer and a Co based magnetic layer on a substrate. The sublayer causes the Cr crystals to avoid growing with a predominantly (200) orientation. Because of this the magnetic layer will be isotropic in the film plane and independent of any texture or scratch marks in the substrate.
TL;DR: In this paper, a wet isotropic etching technique (tubs) was developed for texturing polycrystalline silicon solar cells, which is suitable for thin substrates where the superior light trapping properties will be most beneficial.
Patent•
25 Oct 1996TL;DR: In this article, a laser system with high beam quality and high brightness is used to reduce the heat affected zones (HAZ) of the cut surface, which show seriously disturbed texture and/or micro-cracks.
Abstract: Laser cutting of workpieces according to prior art results in heat affected zones (HAZ) of signiftcant thickness at the cut surface, which show seriously disturbed texture and/or microcracks. The HAZ is diminished by using a laser system with high beam quality and high brightness.
TL;DR: The morphology and microstructure of 3C-SiC thin films grown on Si(111) substrate by chemical vapor deposition at ambient pressure has been investigated in this paper, where Hexamethyldisilane (HMDS) was used as the source gas and a 8% H 2 + Ar mixture as the carrier gas.
TL;DR: In this article, the microstructure of textured TiN films was investigated by scanning electron microscopy and transmission electron microscope, and the results showed that the textured films consist of laminated twinned grains, multiply twinned and nearly thermodynamic equilibrium grains respectively at the growing stage.
Abstract: The 〈100〉, 〈110〉, and 〈211〉 textured TiN films were obtained in a chemical vapor deposition system using TiCl4, N2, and H2 as reaction gases. The microstructure of these textured films was investigated by scanning electron microscopy and transmission electron microscopy. The results show that the 〈211〉, 〈110〉, and 〈100〉 textured films consist of laminated twinned grains, multiply twinned grains, and nearly thermodynamic equilibrium grains respectively at the growing stage. The formation of these textures is discussed based on nucleation and growth mechanisms. At a lower deposition temperature with higher nitrogen concentration, the decahedral multiply twinned and laminated twinned crystals dominate over crystals with single crystalline structure. After competitive growth of these crystals, the multiply twinned crystals with 〈110〉 twin axis perpendicular to substrate surface survive. At an intermediate deposition temperature with lower nitrogen concentration, the laminated twinned crystals dominate the growth and the 〈211〉 orientation along the (111) twin planes possesses the fastest growth rate and form 〈211〉 textured films. At a higher deposition temperature above 1200 °C, the single crystalline structure dominates and forms 〈100〉 textured films. The effect of surface adsorption on texture formation is discussed.
TL;DR: In this paper, the authors compared the properties of different types of TiO2 layers formed on different oriented Ti single crystals of a coarse grain sample using anisotropic micro ellipsometry.
TL;DR: In this article, the orientation changes of a set of grains in a 2 × 2 mm region on an internal surface of a two-part polycrystalline aluminum sample were measured by the Backscattered Kikuchi Diffraction (BKD) technique before and after 40% height reduction in a channel die.