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Showing papers on "Texture (crystalline) published in 2004"


Journal ArticleDOI
TL;DR: In this article, a reactive TGG (RTGGG) was used to obtain highly oriented Pb(Mg1/3Nb2/3)O3-PbTiO3, Sr0.53Ba0.47Nb 2O6, and (N...
Abstract: Crystallographic texturing of polycrystalline ferroelectric ceramics offers a means of achieving significant enhancements in the piezoelectric response. Templated grain growth (TGG) enables the fabrication of textured ceramics with single crystal-like properties, as well as single crystals. In TGG, nucleation and growth of the desired crystal on aligned single crystal template particles results in an increased fraction of oriented material with heating. To facilitate alignment during forming, template particles must be anisometric in shape. To serve as the preferred sites for epitaxy and subsequent oriented growth of the matrix, the template particles need to be single crystal and chemically stable up to the growth temperature. Besides templating the growth process, the template particles may also serve as seed sites for phase formation of a reactive matrix. This process, referred to as Reactive TGG (RTGG), has been used to obtain highly oriented Pb(Mg1/3Nb2/3)O3-PbTiO3, Sr0.53Ba0.47Nb2O6, and (N...

465 citations


Journal ArticleDOI
TL;DR: In this paper, electron backscatter diffraction (EBSD) is employed to characterize the deformation microstructures and textures established during the cold rolling of pure Mg, Mg 0.2Ce and Mg 3Al-1Zn (also known as AZ31).
Abstract: Electron Backscatter Diffraction (EBSD) is employed to characterize the deformation microstructures and textures established during the cold rolling of pure Mg, Mg–0.2Ce and Mg–3Al–1Zn (also known as AZ31). The maximum cold rolling reductions achievable in these alloys prior to failure were ∼30, >90 and ∼15%, respectively. The dominant features of the microstructure were twins and shear bands. The frequency of the former decreased while that of the latter increased with rolling reduction. Each alloy displayed a fibre texture in which the c -axis was closely aligned with the sheet normal direction. There was little change to the rolling textures with increasing rolling reduction beyond ∼10%. Much of the deformation appeared to be concentrated in the shear bands. It is speculated that the striking effect of alloying addition on cold rollability can be understood in terms of differences in severity, frequency and lifetime of shear bands.

431 citations


Journal ArticleDOI
TL;DR: In this paper, the evolution of microstructure and texture of a TWIP-steel during cold rolling was studied, and the presence of deformation twinning at low strains ( e 〈1 1 2〉 is dominant at every strain level.

428 citations


BookDOI
01 Jan 2004
TL;DR: In this paper, a line profile analysis of X-ray diffraction patterns for investigation of nanocrystalline systems is presented, and a Bayesian/maximum entropy method for the certification of a Nanocrystallite-size NIST standard reference material is presented.
Abstract: 1 Line Profile Analysis: A Historical Overview- 2 Convolution Based Profile Fitting- 3 Whole Powder Pattern Modelling: Theory and Applications- 4 Full Profile Analysis of X-ray Diffraction Patterns for Investigation of Nanocrystalline Systems- 5 Crystallite Size and Residual Strain/Stress Modeling in Rietveld Refinement- 6 The Quantitative Determination of the Crystalline and the Amorphous Content by the Rietveld Method: Application to Glass Ceramics with Different Absorption Coefficients- 7 Quantitative Analysis of Amorphous Fraction in the Study of the Microstructure of Semi-crystalline Materials- 8 A Bayesian/Maximum Entropy Method for the Certification of a Nanocrystallite-Size NIST Standard Reference Material- 9 Study of Submicrocrystalline Materials by Diffuse Scattering in Transmitted Wave- 10 Determining the Dislocation Contrast Factor for X-ray Line Profile Analysis- 11 X-ray Peak Broadening Due to Inhomogeneous Dislocation Distributions- 12 Determination of Non-uniform Dislocation Distributions in Polycrystalline Materials- 13 Line Profile Fitting: The Case of fcc Crystals Containing Stacking Faults- 14 Diffraction Elastic Constants and Stress Factors Grain Interaction and Stress in Macroscopically Elastically Anisotropic Solids The Case of Thin Films- 15 Interaction between Phases in Co-deforming Two-Phase Materials: The Role of Dislocation Arrangements- 16 Grain Surface Relaxation Effects in Powder Diffraction- 17 Interface Stress in Polycrystalline Materials- 18 Problems Related to X-Ray Stress Analysis in Thin Films in the Presence of Gradients and Texture- 19 Two-Dimensional XRD Profile Modelling in Imperfect Epitaxial Layers- 20 Three-Dimensional Reciprocal Space Mapping: Application to Polycrystalline CVD Diamond

420 citations


Journal ArticleDOI
TL;DR: In this article, a full approach has been developed integrating novel texture and residual stress methodologies with the Rietveld method (Acta Cryst. 22 (1967) 151) (for crystal structure analysis) and it has been coupled with the reflectivity analysis.

393 citations


Journal ArticleDOI
TL;DR: Monodisperse MnFe2O4 nanoparticles with cubelike and polyhedron shapes were synthesized by reaction of Fe(acac)3 and Mn(acAC)2 with 1,2-hexadecanediol, oleic acid, and oleylamine, leading to nanoparticle superlattices.
Abstract: Monodisperse MnFe2O4 nanoparticles with cubelike and polyhedron shapes were synthesized by reaction of Fe(acac)3 and Mn(acac)2 with 1,2-hexadecanediol, oleic acid, and oleylamine. Controlled evaporation of the particle dispersion led to nanoparticle superlattices. The crystal orientation of the particle in the assembly depends on the shape of the particles, with particles in a cubelike shape showing (100) texture and those in the polyhedron shape exhibiting (110) texture.

339 citations


Journal ArticleDOI
01 Jan 2004-Carbon
TL;DR: This paper showed that very porous carbon materials can be synthesized by evaporative drying and pyrolysis of aqueous resorcinol-formaldehyde gels provided that the operating variables are correctly chosen.

333 citations


Journal ArticleDOI
01 Jan 2004-Carbon
TL;DR: In this article, the effect of liquid-phase oxidation on the texture and surface properties of carbon nanofibers has been studied using XRD, TEM, SEM, N2-physisorption, TGA-MS, XPS and acid-base titrations.

296 citations


Journal ArticleDOI
TL;DR: In this article, the dependence of nanoindentation pile-up patterns and microtextures on the crystallographic orientation using high purity copper single crystals was studied. But the authors focused on the dependence on the texture mappings around the indents.

270 citations


Journal ArticleDOI
TL;DR: In this paper, an overview of the fabrication of epitaxial buffer layers on rolling-assisted biaxially textured substrates (RABiTS) as templates for YBCO films carrying high critical current densities is provided.
Abstract: This article provides an overview of the fabrication of epitaxial, biaxially aligned buffer layers on rolling-assisted biaxially textured substrates (RABiTS) as templates forYBCO films carrying high critical current densities. The RABiTS technique uses standard thermomechanical processing to obtain long lengths of flexible, biaxially oriented substrates with smooth surfaces. The strong biaxial texture of the metal is conferred to the superconductor by the deposition of intermediate metal and/or oxide layers that serve both as a chemical and a structural buffer. Epitaxial YBCO films with critical current densities exceeding 3 x 10 6 A/cm 2 at 77 K in self-field have been grown on RABiTS using a variety of techniques and demonstrate magnetic-field-dependent critical current values that are similar to those of epitaxial films on single-crystal ceramic substrates. The RABiTS architecture most commonly used consists of a CeO 2 (sputtered)/YSZ (sputtered)/Y 2 O 3 (e-beam)/Ni-W alloy. The desired texture of the base metal has been achieved in 100 m lengths and >10 cm widths. Scaleable and cost-effective techniques are also being pursued to deposit the epitaxial multilayers. The results discussed here demonstrate that this technique is a viable route for the fabrication of long lengths of high-critical-current-density wire capable of carrying high currents in magnetic fields and at temperatures accessible by cooling with relatively inexpensive liquid nitrogen (up through the 77 K range).

258 citations



Journal ArticleDOI
TL;DR: In this paper, a microstructure of grain boundary α encircling colonies of Widmanstatten α Electron backscattered diffraction (EBSD) texture measurements showed that the α texture was markedly sharper than that calculated on a basis of equal probability, indicating that significant variant selection was occurring during diffusional transformation.

Journal ArticleDOI
TL;DR: In this article, the angular-dependent critical current density (Jc) in YBa2Cu3O7 films deposited on MgO templates grown by ion-beam-assisted deposition (IBAD), and on single-crystal substrates, is compared.
Abstract: We compare the angular-dependent critical current density (Jc) in YBa2Cu3O7 films deposited on MgO templates grown by ion-beam-assisted deposition (IBAD), and on single-crystal substrates. We identify three angular regimes in which pinning is dominated by different types of correlated and uncorrelated defects. Those regimes are present in all cases, but their extension and characteristics are sample dependent, reflecting differences in texture and defect density. The more defective nature of the films on IBAD turns into an advantage as it results in higher Jc, demonstrating that the performance of the films on single crystals is not an upper limit for the IBAD coated conductors.

Journal ArticleDOI
TL;DR: In this article, the influence of In2O3 film structure on gas-sensing characteristics measured in steady state and transient modes was reported, and it was shown that grain size and porosity are the parameters of In 2O3 films that best control gas response to ozone.

Journal ArticleDOI
TL;DR: In this paper, the Young's modulus of the as-deposited single-crystal Ti3SiC2 films was measured. But the authors revealed the constraints of nucleation due to kinetic limitations at substrate temperatures below 700°C, and there is a competitive TiCx growth with Si segregation to form twin boundaries or Si substitutional incorporation in TiCix.
Abstract: Epitaxial Ti3SiC2(0001) thin films have been deposited by dc magnetron sputtering from three elemental targets of Ti, C, and Si onto MgO(111) and Al2O3(0001) substrates at temperatures of 800–900°C. This process allows composition control to synthesize Mn+1AXn (MAX) phases (M: early transition metal; A: A-group element; X: C and∕or N; n=1–3) including Ti4SiC3. Depositions on MgO(100) substrates yielding the Ti–Si–C MAX phases with (101¯5), as the preferred orientation. Samples grown at different substrate temperatures, studied by means of transmission electron microscopy and x-ray diffraction investigations, revealed the constraints of Ti3SiC2 nucleation due to kinetic limitations at substrate temperatures below 700°C. Instead, there is a competitive TiCx growth with Si segregation to form twin boundaries or Si substitutional incorporation in TiCx. Physical properties of the as-deposited single-crystal Ti3SiC2 films were determined. A low resistivity of 25μΩcm was measured. The Young’s modulus, ascertaine...

Journal ArticleDOI
TL;DR: In this paper, the influence of front TCO thickness, surface texture and different back reflectors on short-circuit current density and fill factor of thin film silicon solar cells were investigated.

Journal ArticleDOI
TL;DR: In this article, the authors used templated grain growth (TGG) to construct textured, textured Sr0.53Ba0.47Nb2O6 ceramics with a relative density of >95% using TGG.
Abstract: Textured Sr0.53Ba0.47Nb2O6 ceramics with a relative density of >95% were fabricated using templated grain growth (TGG). Acicular KSr2Nb5O15 template particles synthesized via a molten salt process were aligned by tape casting in a mixture of solid-state-synthesized SrNb2O6 and BaNb2O6 powders. The resulting ceramics possessed strong fiber texture along the polar axis ([001]) of the strontium barium niobate. Samples with 15.4 wt% templates attained a textured fraction of 0.82 after sintering at a temperature of 1450°C for 4 h. These materials showed peak dielectric constants of 7550 at 1 kHz, remanent polarizations of 13.2 μC/cm2, saturation polarizations of 21 μC/cm2 (60%–85% of the single-crystal value), piezoelectric strain coefficients of 78 pC/N (70%–85% of the single-crystal value), and room-temperature pyroelectric coefficients of 2.9 × 10−2μC·(cm2·°C)−1 (52% of the single-crystal value). These results show that TGG is a viable option for accessing single-crystal properties in polycrystalline ceramics.

Journal ArticleDOI
TL;DR: In this article, the deformation induced martensitic transformation was investigated in metastable austenitic stainless steel, which can present a microstructure of austenite (γ), α′ martensite and non magnetic e martensites.
Abstract: Deformation induced martensitic transformation was investigated in metastable austenitic stainless steel. This steel can present a microstructure of austenite (γ), α′ martensite and non magnetic e martensite. Uni-axial tensile test was used for loading at different temperatures below room temperature (from −120 to 20 °C). During the deformation the transformation takes place at certain places in an anisotropic way and texture also develops. Quantitative phase analysis was done by X-ray diffraction (XRD) and magnetic methods while the texture was described by X-ray diffraction using a special inverse pole figure. The quantitative phase analysis has shown that the formation of α′ and e martensite from austenite is the function of deformation rate, and deformation temperature. The transformation of the textured austenite takes place in an anisotropic way and a well defined crystallographic relationship between the parent and α′ martensite phase has been measured.

Journal ArticleDOI
TL;DR: In this paper, texture evolution and heterogeneity during equal channel angular extrusion (ECAE) of an annealed pure copper billet are investigated using a combined finite element-polycrystal modeling approach.

Journal ArticleDOI
TL;DR: In this article, the results showed that the substrate bias significantly affects the surface morphology, crystalline phases and texture of thin copper oxide thin films with and without substrate bias, and the results show that the film with bias exhibits a more uniform and clearer surface morphology although both kinds of films are very smooth.
Abstract: Copper oxide thin films deposited on Si (100) by a filtered cathodic vacuum arc with and without substrate bias have been studied by atomic force microscopy, x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The results show that the substrate bias significantly affects the surface morphology, crystalline phases and texture. In the film deposited without bias, two phases—cupric oxide (CuO) and cuprous oxide (Cu2O)—coexist as cross-evidenced by XRD, XPS and Raman analyses, whereas CuO is dominant concurrent with CuO (020) texture in the film deposited with bias. The film deposited with bias exhibits a more uniform and clearer surface morphology although both kinds of films are very smooth. Some explanations are given as well.

Journal ArticleDOI
TL;DR: In this paper, a thorough study of the microstructure, texture, intrinsic stress, surface and interface morphology of transition metal nitride (mainly TiN but also CrN) films grown on Si by reactive sputter deposition is presented, with emphasis to the mechanisms of adatom migration on the surface and subplantation of energetic species.
Abstract: We present a thorough study of the microstructure, texture, intrinsic stress, surface, and interface morphology of transition metal nitride (mainly TiN but also CrN) films grown on Si by reactive sputter deposition, with emphasis to the mechanisms of adatom migration on the surface and subplantation of energetic species. In order to study the effects of adatom mobility and the subplantation probability we vary the ion energy and growth temperature. For the experimental part of this work we used nondestructive, statistically reliable x-ray techniques (diffraction, reflectivity, scattering). The x-ray results are compared and correlated with supporting data of in situ spectroscopic ellipsometry as well as Monte Carlo simulations of the irradiation effects and surface diffusion of adatoms. We found that the texture and the surface and interface morphology are sensitive to the mechanism of dissipation of the impinging ions. If the energy is enough to overcome the subplantation threshold (∼50eV), then the film...

Journal ArticleDOI
Wen Gong1, Jing-Feng Li1, Xiangcheng Chu1, Zhilun Gui1, Longtu Li1 
TL;DR: In this article, a seeding layer was introduced between the most underlying surface of the PZT film and the platinum electrode surface to control the texture of the pZT thin film.

Journal ArticleDOI
TL;DR: In this article, the effects of the electrolytic bath acidity, or pH, on the magnetic properties in arrays of electrodeposited Co nanowires and their correlation with the crystalline properties have been studied using ferromagnetic resonance.
Abstract: The effects of the electrolytic bath acidity, or pH, on the magnetic properties in arrays of electrodeposited Co nanowires and their correlation with the crystalline properties have been studied using ferromagnetic resonance. The results show that, depending on the value of the pH of the electrolyte, appreciable changes in the effective anisotropy can be induced. These changes are attributed to modifications in the microstructure of the Co nanowires. In particular, quantification of the effective anisotropy field shows that the microstructure of the deposited Co wires can be set to contain a dominant fraction of the Co-hcp phase with the c-axis oriented perpendicular to the wires, for pH values of 3.8-4.0, or parallel to the wires, for pH values >or=6.0. This results in a competitive or additive magnetocrystalline contribution to the total anisotropy field. Furthermore, at a pH value of 2.0, no contribution from the magnetocrystalline anisotropy is present, indicating a lack of texture in the Co microstructure. As a result, the effective anisotropy can be controlled over a field range of 5 kOe.

Journal ArticleDOI
TL;DR: In this article, the microstructure features of polycrystalline diamond were analyzed using transmission electron microscopy and electron diffraction, and it was shown that the diamond particles in the homogeneous fine structure are transformed from graphite in the diffusion process, while diamond layers in the lamellar structure are formed in the martensitic process via the hexagonal diamond phase.
Abstract: Recently, ultra-hard polycrystalline diamond was synthesized from graphite by direct conversion under static high pressure. This paper describes the microstructure features of thus formed polycrystalline diamond. Transmission electron microscopy and electron diffraction have revealed that the polycrystalline diamond has a mixed texture of a homogeneous fine structure and a lamellar structure. The former structure consists of fine-grained diamond particles of several tens of nanometers across, which are randomly oriented. The latter structure has bending diamond layers, which may reflect deformed shapes of locally layered graphite of starting material. The experimental results suggest that diamond particles in the homogeneous fine structure are transformed from graphite in the diffusion process, while diamond layers in the lamellar structure are formed in the martensitic process from graphite via the hexagonal diamond phase. It is also noted that significant grain growth occurred at a high temperature of ∼2700°C, and the lamellar structure was segmentalized to form new grain boundaries.

Journal ArticleDOI
A. A. Francis1
TL;DR: In this article, the devitrification behavior of different sizes of slag-derived glass was investigated using differential thermal analysis, X-ray diffraction and scanning electron microscopy to determine the possibility of preparing glass-ceramic materials.
Abstract: The devitrification behavior of different sizes of slag-derived glass was investigated using differential thermal analysis, X-ray diffraction and scanning electron microscopy to determine the possibility of preparing glass-ceramic materials. The crystalline phases were identified as gehlenite, diopside pyroxene and barium aluminium silicate. The degree of crystallization was determined by evaluation the changes of density at different temperatures where a maximum density was achieved at 900 °C. A remarkable difference in the glass-ceramic texture was observed by treating the sample at different crystallization temperatures. Both acicular and dendritic morphology have been identified in the sample heat-treated at 1050 °C. A slight variation in peak crystallization temperature with particle size indicated a bulk crystallization mechanism.

Journal ArticleDOI
TL;DR: In this paper, X-ray diffractograms and transmittance curves were used to characterize polycrystalline In 2 O 3 :Sn (ITO) films with thickness between 40 nm and 1.7 μm and attributed the differences in the properties of the thin and thick films to a change of the film's microstructure taking place at 0.3-0.5 μm with more additional oxygen incorporated into the thinner films.

Journal ArticleDOI
TL;DR: In this paper, a grain orientation was mapped by orientation image microscopy, as the directionally solidified material was deformed in steps of 10% to a total height reduction of 40%.
Abstract: Deformation studies at grain level have been performed in order to model how individual crystals in a polycrystalline material deform. The experiment was carried out by plane–strain compression of a high–purity polycrystalline aluminium with columnar grain structure with near 〈100〉 fibre texture parallel to the constrained direction in the channel die. This structure was chosen to allow a fully three–dimensional characterization of the grain structure. The grain orientations were mapped by orientation image microscopy, as the directionally solidified material was deformed in steps of 10% to a total height reduction of 40%. The grains were found either to show nearly uniform rotations or to split into two types of deformation bands, either with repeating orientation fields or with non–repeating orientation fields. The Taylor model and the finite–element method (FEM) were, as usual, quite successful in predicting the average deformation texture, but the Taylor model failed totally to predict the rotation of individual grains. The FEM was more successful in predicting the individual grain rotations but did not, as in a previous study, predict the morphology of the deformation bands. The significant discovery, made here, was that it appeared possible to model the local deformation at a grain scale, from the observed individual deviations of the grain rotations from those predicted if each grain underwent just the plane–strain conditions imposed on the sample. Plastic work rates were computed allowing four shears (two shears in each of the two contact planes) that are compatible with the channel–die geometry. It was found that in all the ‘hard’ grains (those with high Taylor factors), the additional shears (in type and magnitude) that minimized the plastic energy dissipation rate were the same shears that were needed to match the observed grain rotations. Adjacent Taylor ‘soft’ grains were found to have been subjected to the additional shears imposed by their neighbouring hard grains. This was true even when these shears raised the plastic work of the soft grains. This effect was most marked when the soft grains were small in size. These additional shears found by this plastic work analysis were consistent with the observed additional shear seen in the overall shape change of the sample. The grains forming non–repeating orientation fields had low initial Taylor factors and were surrounded by high–Taylor–factor grains, usually of larger size, but which had adopted somewhat different extra shears. The grains showing repeating orientation fields were found to have an orientation, near ‘cube’, (001) 〈100〉, which was initially unstable, leading to a break–up into different orientation fields when deformed. These differing deformation bands in the cube grains followed different strain paths, which also minimized their plastic work.

Journal ArticleDOI
TL;DR: In this article, the effect of cube texture on the initiation of localized necking is studied numerically and the forming limit diagram is constructed based on crystal plasticity theory in conjunction with the well-known M-K approach.
Abstract: The effect of the cube texture on the initiation of localized necking is studied numerically. The forming limit diagram (FLD) is constructed based on crystal plasticity theory in conjunction with the well-known M–K approach. It is found that, while the ideal cube texture decreases formability, a spread about cube significantly delays the initiation of localized necking when a sheet undergoes biaxial tension. The effect of the cube texture on the predicted FLDs is discussed in terms of the sharpness of the yield locus near equi-biaxial tension.

Journal ArticleDOI
TL;DR: In this article, structural and superconducting properties of MgB2 thin films doped with carbon during the hybrid physical-chemical vapor deposition process were studied, and a carbon-containing precursor was added to the carrier gas to achieve carbon doping.
Abstract: We have studied structural and superconducting properties of MgB2 thin films doped with carbon during the hybrid physical-chemical vapor deposition process. A carbon-containing precursor metalorganic bis(methylcyclopentadienyl)magnesium was added to the carrier gas to achieve carbon doping. As the amount of carbon in the film increases, the resistivity increases, Tc decreases, and the upper critical field increases dramatically as compared to clean films. The self-field Jc in the carbon doped film is lower than that in the clean film, but Jc remains relatively high to much higher magnetic fields, indicating stronger pinning. Structurally, the doped films are textured with columnar nano-grains and highly resistive amorphous areas at the grain boundaries. The carbon doping approach can be used to produce MgB2 materials for high magnetic-field applications.

Journal ArticleDOI
TL;DR: In this article, the thermal conductivities of several TBCs were studied, including single-layer and multilayer coatings consisting of Al2O3 and ZrO2 partially stabilized with 8 wt% Y 2O3 (8YSZ) were deposited on nickel-base superalloy substrates by EB-PVD.
Abstract: Thermal conductivity is one of the most important properties in the design of thermal barrier coatings (TBCs) for high-temperature gas-turbine blades. In the present study, the thermal conductivities of several TBCs were studied. Single-layer and multilayer coatings consisting of Al2O3 and ZrO2 partially stabilized with 8 wt% Y2O3 (8YSZ) were deposited on nickel-base superalloy substrates by electron-beam physical vapor deposition (EB-PVD). A columnar microstructure with (200) texture and [200] direction oriented nearly perpendicularly to the plane of the coating was observed in the single-layer 8YSZ coating. In multilayer coatings with alternating layers of Al2O3 and 8YSZ, the tendency to develop columnar structure, as well as the intensity of (200) texture, decreased as the number of layers increased. In both the single-layer and multilayer coatings, the 8YSZ layer consisted almost entirely of tetragonal (t) phase with a negligible amount of monoclinic (m) phase. This was in contrast to the microstructure of bulk 8YSZ (source material used for deposition), which contained a significant amount of m phase, in addition to t phase. Whereas bulk Al2O3 consisted of α-phase, only γ-phase was found in the Al2O3 layers of coatings. The thermal conductivities of these coatings were measured by the laser flash method. The thermal conductivity data of single-layer 8YSZ coating compared well with the data on bulk ZrO2 stabilized by 5.3 wt% Y2O3 reported in the literature. This was due to the similarity of microstructures between the two. The thermal conductivity data of multilayer coatings were well described by a series heat-transfer model calculation within the limits of experimental errors involved in the measurements.