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Pole Figures (pole + figure)

Distribution by Scientific Domains

Polymers and Materials Science	61%
Physics and Astronomy	15%

Selected Abstracts

Heteroepitaxial YAlO3 Films on (100)SrTiO3 Substrates: The Use of Pole Figures as a Non-invasive Tool to Assess the Direction of Growth,

CHEMICAL VAPOR DEPOSITION, Issue 1-2 2008
G. Malandrino
Abstract YAlO3 films are grown on (100)SrTiO3 substrates through an in-situ novel metal-organic (MO)CVD strategy involving a molten source consisting of the second-generation Y(hfa)3·diglyme (Hhfa,=,1,1,1,5,5,5-hexafluoro-2,4-pentanedione, diglyme,= bis(2-methoxyethyl)ether) precursor which acts as a solvent for the Al(acac)3 (Hacac,=,acetylacetone). The X-ray diffraction (XRD) patterns show that the films are crystalline and highly oriented, while compositional analysis indicates that the films possess the correct 1:1 ratio. Pole figures are applied as a simple, economic, non-invasive tool to assess the growth direction of YAlO3 films. [source]

On the capability of revealing the pseudosymmetry of the chalcopyrite-type crystal structure

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 3 2008
D. Abou-Ras
Abstract The tetragonal crystal-structure type of chalcopyrites (chemical formula AIBIIICVI2) is a superstructure of sphalerite type. The c /a ratio differs generally from the ideal value 2, i.e., the crystal structure is pseudocubically distorted. For CuInSe2 and CuGaSe2 thin films, simulations demonstrate that it is theoretically possible to reveal the tetragonality in electron backscatter-diffraction (EBSD) patterns for CuGaSe2, whereas it may not be possible for CuInSe2. EBSD experiments on CuGaSe2 thin films using the "Advanced Fit" band-detection method show that it is possible to extract accurate misorientation-angle distributions from the CuGaSe2 thin film. Pole figures revealing the texture of the CuGaSe2 thin film are shown, which agree well with X-ray texture measurements from the same layer. (© 2008 WILEY -VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Crystal form and orientation of isotactic polypropylene samples prepared by vibration-injection molding

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2007
Jie Zhang
Abstract A vibration,injection molding equipment was developed to prepare isotactic polypropylene injection samples to investigate their crystal form and orientation. Wide-angle X-ray scattering experiments (WAXD) were conducted in two modes: theta,theta mode and tube-fixed mode. Through vibration,injection molding, in additional to , form, , form, or , form can be obtained under different conditions. At high melt temperature (230), ,-PP can be induced and the core of the sample contains more ,-PP than the surface. At low melt temperature (190), ,-PP can be induced and the core and the surface of the sample contain approximate same proportion of ,-PP. Pole figures show that ,-PP of a static sample just orientates slightly along M direction, while that of vibration samples orientate much stronger. The orientation of the normal of (040), plane of the sample obtained at T = 230°C, f = 0.5 Hz, and Pv = 75MPa is preferred in M direction, and the orientation of the normal of (040), plane of the sample obtained at T = 190°C, f = 1.5 Hz, and Pv= 35 MPa is preferred in N direction. ,-PP and ,-PP do not show obvious orientation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 [source]

Heteroepitaxial YAlO3 Films on (100)SrTiO3 Substrates: The Use of Pole Figures as a Non-invasive Tool to Assess the Direction of Growth,

GenOVa: a computer program to generate orientational variants

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 6 2007
Cyril Cayron
A computer program called GenOVa, written in Python, calculates the orientational variants, the operators (special types of misorientations between variants) and the composition table associated with a groupoid structure. The variants can be represented by three-dimensional shapes or by pole figures. [source]

Morphology and texture development of uniaxially stretched poly(ethylene naphthalene-2,6-dicarboxylate)

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007
A. Douillard
Abstract The texture development of PEN films with different semicrystalline morphologies have been studied by X-ray diffraction. These different structures have been obtained by uniaxially stretching PEN amorphous films at 100 and 160°C (below and above Tg) at different drawing ratios. Samples have also been characterized by DSC to determine the crystallinity ratios, the crystallization, and melting temperatures. To define the orientation of crystallites in the oriented samples, pole figures have been constructed, as a function of temperature and drawing ratio (DR) in the range 1.5,4. In the range from DR = 2 to 4 the orientation is clearly uniplanar-axial. At Tdraw = 100°C the crystallinity shown by DSC analysis is higher than the sample stretched at 160°C. The orientation is also higher when samples are stretched at 100°C. The naphthalene rings mainly stay in the plane of the film with a lower fraction perpendicular to the plane of the film. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 395,401, 2007 [source]

When epitaxy controls garnet growth

JOURNAL OF METAMORPHIC GEOLOGY, Issue 4 2007
R. SPIESS
Abstract Within a mica schist from the coesite-bearing Brossasco-Isasca Unit (Western Alps), microstructural analysis shows that Alpine garnet grains are aligned with the crenulated foliation. Garnet crystallographic orientation was analysed with electron backscatter diffraction (EBSD): the obtained crystallographic dispersion patterns and distribution patterns of misorientation axes suggest a strong parallelism of {110} garnet planes with a 56°W-dipping foliation. The data are interpreted as evidence for an epitaxial growth of garnet upon (001) biotite planes, sometime during and/or after dispersion of the biotite/garnet crystals from their initially foliation-parallel orientation by rotation about the Alpine crenulation axis. This interpretation is based on the comparison of the measured EBSD data with: (i) theoretical dispersion trajectories of garnet crystallographic data, (ii) numerically modelled pole figures, and (iii) numerically modelled misorientation axis distribution patterns. Our data suggest that epitaxial growth of garnet upon biotite is allowed by distortion of the pseudohexagonal basal oxygen ring structure on (001) biotite surfaces, and that distortion is driven by introduction of missing ions. Our data further suggest that the spatial distribution of precursor phases influences the distribution patterns of garnet within mica schists. [source]

Experimental Investigation of Eclogite Rheology and Its Fabrics at High Temperature and Pressure

JOURNAL OF METAMORPHIC GEOLOGY, Issue 2 2007
J. ZHANG
Abstract Eclogite plays an important role in mantle convection and geodynamics in subduction zones. An improved understanding of processes in the deeper levels of subduction zones and collision belts requires information on eclogite rheology. However, the deformation processes and associated fabrics in eclogite are not well understood. Incompatible views of deformation mechanism have been proposed for both garnet and omphacite. We present here deformation behaviour of eclogite at temperatures of 1027,1427 °C, confining pressures of 2.5,3.5 GPa, and strain rates of 1 × 10,5 s,1 to 5 × 10,4 s,1. We obtained a power-law creep for the high temperature and pressure deformation of a ,dry' eclogite (50 vol.% garnet, 40% omphacite and 10% quartz) with A = 103.3 ± 1.0, n = 3.5 ± 0.4, ,E =403 ± 30 KJ mol,1 and ,V = 27.2 cm3 mol,1. The two principal minerals of eclogite have greatly different strengths. Progressive increase of garnet results in a smooth increase in strength. Analysis by electron back-scattered diffraction shows that: (1) garnet displays pole figures with near random distributions of misorientation angle under both dry and wet conditions; (2) omphacite shows pronounced lattice preferred orientations (LPOs), suggesting a dominant dislocation creep mechanism. Further investigation into the water effects on eclogite show: (3) water content does not influence the style of omphacite fabric but increases slightly the fabric strength; (4) grain boundary processes dominate the deformation of garnet under high water fugacity or high shear-strain conditions, yielding a random LPO similar to that of non-deforming garnet, despite the strong shape preferred orientation (SPO) observed. {110} [001] slip may dominate the deformation of rutile. Quartz displays complicated and inconsistent LPOs in eclogite. These results are remarkably similar to observations from deformed eclogites in nature. [source]

Texture Development in Silicon Nitride,Silicon Oxynitride In Situ Composites via Superplastic Deformation

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2000
Rong-Jun Xie
Silicon nitride,silicon oxynitride (Si3N4,Si2N2O) in situ composites have been fabricated via either the annealing or the superplastic deformation of sintered Si3N4 that has been doped with a silica-containing additive. In this study, quantitative texture measurements, including pole figures and X-ray diffraction patterns, are used in conjunction with scanning electron microscopy and transmission electron microscopy techniques to examine the degree of preferred orientation and texture-development mechanisms in these materials. The results indicate that (i) only superplastic deformation can produce strong textures in the ,-Si3N4 matrix, as well as Si2N2O grains that are formed in situ; (ii) texture development in the ,-Si3N4 matrix mainly results from grain rotation via grain-boundary sliding; and (iii) for Si2N2O, a very strong strain-dependent texture occurs in two stages, namely, preferred nucleation and anisotropic grain growth. [source]

X-ray characterization of epi-Ge/Pr2O3/Si(111) layer stacks by pole figures and reciprocal space mapping

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 8 2009
Peter Zaumseil
Abstract An epi-Ge/Pr2O3/Si(111) layer structure prepared by consecutive steps of epitaxial deposition and annealing is used to demonstrate the possibility of a complex characterization by combination of different X-ray diffraction techniques. Especially pole figure measurements, reciprocal space mapping (RSM) and high resolution (HR) ,/2, scans at selected inclined netplanes were successfully used to determine the in-plane lattice orientation of the layers relative to the substrate, the strain state of all layers and the structural perfection of the epi-Ge film. It was found that the major part of the epi-Ge layer has the same type A stacking orientation as the Si substrate, but about 0.6% is of type B. The Pr2O3 buffer layer exhibits type B only. The strain state of oxide and epi-Ge was determined, and a small difference in the lattice constant of type A and B epi-Ge was found. Microtwins lying in inclined {111} planes were unambiguously identified by pole figure measurements as the dominating structural defects in the epi-Ge layer. They cause a characteristic scattering pattern in reciprocal space maps. The proposed combination of X-ray techniques allows a relatively fast, integral and non-destructive analysis of heteroepitaxial semiconductor oxide semiconductor structures. [source]

Development of orientation and mechanical properties of extrusion cast polyamide 11 films in biaxial stretching process

POLYMER ENGINEERING & SCIENCE, Issue 5 2002
Sangkeun Rhee
The development of orientation of extrusion cast polyamide 11 films in the biaxial stretching process was studied with birefringence and wide angle X-ray diffraction (WAXD) pole figures. White-Spruiell biaxial orientation factors of the crystalline phase were calculated with the pole figure data. Both biaxially stretched films were developed. Planarity of hydrogen bonding planes with respect to the film surface was observed from WAXD pole figures. Mechanical properties of the films were studied. Tensile strength and elongation at break were successfully correlated with the out-of-plane birefringences. [source]

Molecular orientation, crystallinity, and flexural modulus correlations in injection molded polypropylene/talc composites

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 5 2010
Marcia Cristina Branciforti
Abstract In order to promote better understanding of the structure-mechanical properties relationships of filled thermoplastic compounds, the molecular orientation and the degree of crystallinity of injection molded talc-filled isotactic polypropylene (PP) composites were investigated by X-ray pole figures and wide-angle X-ray diffraction (WAXD). The usual orientation of the filler particles, where the plate planes of talc particles are oriented parallel to the surface of injection molding and influence the orientation of the , -PP crystallites was observed. The PP crystallites show bimodal orientation in which the c - and a*-axes are mixed oriented to the longitudinal direction (LD) and the b -axis is oriented to the normal direction (ND). It was found that the preferential b -axis orientation of PP crystallites increases significantly in the presence of talc particles up to 20,wt% in the composites and then levels-off at higher filler content. WAXD measurements of the degree of crystallinity through the thickness of injection molded PP/talc composites indicated an increasing gradient of PP matrix crystallinity content from the core to the skin layers of the molded plaques. Also, the bulk PP crystallinity content of the composites, as determined by DSC measurements, increased with talc filler concentration. The bulk crystallinity content of PP matrix and the orientation behavior of the matrix PP crystallites and that of the talc particles in composites are influenced by the presence of the filler content and these three composite's microstructure modification factors influence significantly the flexural moduli and the mechanical stiffness anisotropy data (ELD/ETD) of the analyzed PP/talc composites. Copyright © 2009 John Wiley & Sons, Ltd. [source]