Cross-sectional texture of carbon fibres analysed by scanning microbeam X-ray diffraction

2001 ◽  
Vol 34 (4) ◽  
pp. 473-479 ◽  
Author(s):  
Oskar Paris ◽  
Dieter Loidl ◽  
Martin Müller ◽  
Helga Lichtenegger ◽  
Herwig Peterlik

Scanning microbeam X-ray diffraction analysis of single carbon fibres allows the cross-sectional orientation distribution (texture) of the carbon layers to be determined, even when the fibre axis is oriented perpendicular to the X-ray beam (fibre geometry). The fibre is scanned across a microbeam with a diameter significantly smaller than the fibre diameter, and fibre diffraction patterns are recorded for every scanning step. The cross-sectional texture information is obtained from the integrated intensities of two different equatorial reflections as a function of the position on the fibre. As an example, results from two different types of carbon fibres are presented: a polyacrylonitrile-based fibre, with random cross-sectional texture, and a fibre based on mesophase pitch, which exhibits a radially folded cross-sectional texture. Detailed modelling of the diffraction data allows a quantitative description of the radial folded texture.

1976 ◽  
Vol 31 (9-10) ◽  
pp. 612-621 ◽  
Author(s):  
W Müller-Klieser ◽  
W Kreutz

Abstract Mitochondria were isolated using sorbitol and high buffer concentration in the medium. X-ray diffraction patterns arising from the mitochondrial cristae-membrane were recorded in the fully dried state and in two different states in humidity. The Q-function evaluation of these X-ray dif­fraction diagrams resulted in electron density cross-section profiles, which consist of two main peaks of opposite sign and one, respectively two, smaller peaks. The total thickness of the membrane amounts to 120 Å in the dry and 140 Å to 160 Å in the wet state.An interpretation of the cross-section profile is tentatively proposed.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Wei-Lin Wang ◽  
Chia-Ti Wang ◽  
Wei-Chun Chen ◽  
Kuo-Tzu Peng ◽  
Ming-Hsin Yeh ◽  
...  

Ta/TaN bilayers have been deposited by a commercial self-ionized plasma (SIP) system. The microstructures of Ta/TaN bilayers have been systematically characterized by X-ray diffraction patterns and cross-sectional transmission electron microscopy. TaN films deposited by SIP system are amorphous. The crystalline behavior of Ta film can be controlled by the N concentration of underlying TaN film. On amorphous TaN film with low N concentration, overdeposited Ta film is the mixture ofα- andβ-phases with amorphous-like structure. Increasing the N concentration of amorphous TaN underlayer successfully leads upper Ta film to form pureα-phase. For the practical application, the electrical property and reliability of Cu interconnection structure have been investigated by utilizing various types of Ta/TaN diffusion barrier. The diffusion barrier fabricated by the combination of crystallizedα-Ta and TaN with high N concentration efficiently reduces the KRc and improves the EM resistance of Cu interconnection structure.


1994 ◽  
Vol 351 ◽  
Author(s):  
Shizuo Tokito ◽  
J. Sakata ◽  
Y. Taga

ABSTRACTA new class of superlattices consisting of alternating layers of organic and inorganic materials has been prepared from 8-hydroxyquinoline aluminium (Alq), copper phthalocyanine (CuPc), 3,4,9,10-perylenetetracarboxylic diimide (PTCDI) and MgF2 by molecular beam deposition. Small-angle x-ray diffraction data and cross-sectional transmission electron micrograph of the superlattices reveal that the superlattices have layered structure throughout the entire stack. From comparison of the x-ray diffraction patterns, it is found that the interface roughness between organic and MgF2 layers depends on the materials for organic layers. High-angle x-ray diffraction data indicate that there is a structural ordering in the CuPc and PTCDI layers. From the optical absorption and photoluminescence measurements, it is found that the exciton energy of Alq shifts to higher energy with decreasing Alq layer thickness.


2001 ◽  
Vol 16 (4) ◽  
pp. 198-204 ◽  
Author(s):  
C. K. Lowe-Ma ◽  
W. T. Donlon ◽  
W. E. Dowling

Retained austenite is an important characteristic of properly heat-treated steel components, particularly gears and shafts, that will be subjected to long-term use and wear. Normally, either X-ray diffraction or optical microscopy techniques are used to determine the volume percent of retained austenite present in steel components subjected to specific heat-treatment regimes. As described in the literature, a number of phenomenological, experimental, and calculation factors can influence the volume fraction of retained austenite determined from X-ray diffraction measurements. However, recent disagreement between metallurgical properties, microscopy, and service laboratory values for retained austenite led to a re-evaluation of possible reasons for the apparent discrepancies. Broad, distorted X-ray peaks from un-tempered martensite were found to yield unreliable integrated intensities whereas diffraction peaks from tempered samples were more amenable to profile fitting with standard shape functions, yielding reliable integrated intensities. Retained austenite values calculated from reliable integrated intensities were found to be consistent with values obtained by Rietveld refinement of the diffraction patterns. The experimental conditions used by service laboratories combined with a poor choice of diffraction peaks were found to be sources of retained austenite values containing significant bias.


1987 ◽  
Vol 105 (3) ◽  
pp. 1311-1318 ◽  
Author(s):  
J Bordas ◽  
G R Mant ◽  
G P Diakun ◽  
C Nave

Synchrotron radiation techniques have enabled us to record meridional x-ray diffraction patterns from frog sartorius muscle at resolutions ranging from approximately 2,800 to 38 nm (i.e., overlapping with the optical microscope and the region normally accessible with low angle diffraction cameras). These diffraction patterns represent the transform of the low resolution structure of muscle projected on the sarcomere axis and sampled by its repeat. Altering the sarcomere length results in the sampling of different parts of this transform, which induces changes in the positions and the integrated intensities of the diffraction maxima. This effect has been used to determine the transform of the mass projection on the muscle axis in a quasicontinuous fashion. The results reveal the existence of maxima arising from long-range periodicities in the structure. Determination of the zeroes in the transforms has been used to obtain phase information from which electron density maps have been calculated. The x-ray diffraction diagrams and the resulting electron density maps show the existence of a series of mass bands, disposed transversely to the sarcomere axis and distributed at regular intervals. A set of these transverse structures is associated with thin filaments, and their 102.0-nm repeat suggests a close structural relationship with their known molecular components. A second set, spaced by approximately 230.0 nm, is also present; from diffraction theory one has to conclude that this repeat simultaneously exists in thick and thin filament regions.


2011 ◽  
Vol 204-210 ◽  
pp. 1741-1744
Author(s):  
Li Jie Wang ◽  
Jun Sheng Yang ◽  
Bo Sun ◽  
Xiao Dong Tian

A composite coating was prepared on Ti-6Al-4V surface by the combination of nitriding, Mo-sputtering and sulfurizing treatments. The microstructure and phase constituent of the composite coating were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. Furthermore, the cross-sectional hardness gradient of the coating was determined. The results revealed that the composite coating consisted of Ti, Mo, MoS2, TiN and transition layer and the grain size of the sulfides formed on the coating surface were different with treatment temperature. The examination of the cross-sectional hardness of the composite coating revealed that the coating was an ideal tribological surface.


Open Physics ◽  
2008 ◽  
Vol 6 (3) ◽  
Author(s):  
Hua Li ◽  
Jianping Sang ◽  
Chang Liu ◽  
Hongbing Lu ◽  
Juncheng Cao

AbstractSingle crystalline ZnO film is grown on GaN/sapphire (0001) substrate by molecular beam epitaxy. Ga2O3 is introduced into the ZnO/GaN heterostructure intentionally by oxygen-plasma pre-exposure on the GaN surface prior to ZnO growth. The crystalline orientation and interfacial microstructure are characterized by X-ray diffraction and transmission electron microscopy. X-ray diffraction analysis shows strong c-axis preferred orientation of the ZnO film. Cross-sectional transmission electron microscope images reveal that an additional phase is formed at the interface of ZnO/GaN. Through a comparison of diffraction patterns, we confirm that the interface layer is monoclinic Ga2O3 and the main epitaxial relationship should be $$ (0001)_{ZnO} \parallel (001)_{Ga_2 O_3 } \parallel (0001)_{GaN} $$ and $$ [2 - 1 - 10]_{ZnO} \parallel [010]_{Ga_2 O_3 } \parallel [2 - 1 - 10]_{GaN} $$.


1997 ◽  
Vol 475 ◽  
Author(s):  
J.D. Jarratt ◽  
T.J. Klemmer ◽  
J.A. Barnard

ABSTRACTThe microstructure of Co90Feio/Ag giant magnetoresistive multilayer films has been investigated using x-ray diffraction (XRD) and cross-sectional transmission electron microscopy. Columnar grains with a (111) fiber growth texture is observed. A comparison is made between the observed layering structure and earlier multilayer schematics based on the literature and magnetic and magnetoresistive measurements as a function of layer thickness. A direct correlation is made between superlattice satellite peak signals from selected area electron diffraction patterns and XRD scans.


1999 ◽  
Vol 596 ◽  
Author(s):  
R. N. Jacobs ◽  
R. P. Godfrey ◽  
W. L. Sarney ◽  
C. W. Tipton ◽  
L. Salamanca-Riba

AbstractTransmission electron microscopy is used to examine the structural characteristics of Pb0.9La0.1Zr0.2Ti0.8O3 (PLZT) films grown directly on single crystal LaAlO3 (LAO) substrates. In particular, the domain orientation and film epitaxial quality as a function of substrate deposition temperature are obtained in the range 500–650°C and compared to x-ray diffraction results. High-resolution cross sectional images and electron diffraction patterns confirm that domain orientation and overall epitaxial quality can be optimized with growth temperature. In addition, these results show a direct correlation with pyroelectric measurements obtained for capacitor structures incorporating La1−xSrxCoO3 (LSCO) top and bottom electrodes.


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