Characterization of Conductive Anodic Filament (Caf) by X-Ray Microtomography and by Serial Sectioning

1993 ◽  
Vol 323 ◽  
Author(s):  
S. R. Stock ◽  
L. L. Dollar ◽  
G. B. Freeman ◽  
W. J. Ready ◽  
L. J. Turbini ◽  
...  

ABSTRACTX-ray microtomography is used to nondestructively section printed wiring boards in which conductive anodic filaments (CAFs) had grown, Quantification of the spatial distribution of copper is compared for microtomography and for serial sections obtained in SEM with backscattered electrons. The agreement between the techniques is excellent and indicates that microtomography may be used confidently to follow the subsurface growth of CAFs.

2007 ◽  
Vol 330-332 ◽  
pp. 503-506
Author(s):  
Xiao Wei Fu ◽  
Jie Huang ◽  
E.S. Thian ◽  
Serena Best ◽  
William Bonfield

A Bioglass® reinforced polyethylene (Bioglass®/polyethylene) composite has been prepared, which combines the high bioactivity of Bioglass® and the toughness of polyethylene. The spatial distribution of Bioglass® particles within the composite is important for the performance of composites in-vivo. Recent developments in X-ray microtomography (XμT) have made it possible to visualize internal and microstructural details with different X-ray absorbencies, nondestructively, and to acquire 3D information at high spatial resolution. In this study, the volume fraction and 3D spatial distribution of Bioglass® particles has been acquired quantitatively by XμT. The information obtained provides a foundation for understanding the mechanical and bioactive properties of the Bioglass®/polyethylene composites.


2019 ◽  
Vol 70 (6) ◽  
pp. 1956-1959
Author(s):  
Zizi Ileana Balta ◽  
Ioana Demetrescu ◽  
Irina Petroviciu ◽  
Mihai Lupu

In the present study, golden threads from two, apparently identical, medieval epitrachelions considered masterpieces of the Romanian Byzantine embroidery art, were investigated by using Micro-Particle Induced X-ray Emission (micro-PIXE) and optical microscopy. PIXE measurements allowed to accurate identify the elemental composition, distribution of the trace elements, the layered structures (depth profiling) and thicknesses of the gold layer. Useful information for the characterization of the gilded silver threads due to elemental maps concerning the constituent elements spatial distribution in the sample was also obtained.


2007 ◽  
Vol 558-559 ◽  
pp. 751-756 ◽  
Author(s):  
Kristofer Hannesson ◽  
Dorte Juul Jensen

Grain structures in polycrystalline materials are typically three dimensional (3D) structures, but by far the most characterizations of grain structures are done by microscopy and are thus limited to 2D. In the present work 3D grain structures in a well-annealed cylindrical aluminium (AA1050) sample is characterized and analyzed. The characterization is done by 2 methods i) by non-destructive 3-dimensional x-ray diffraction (3DXRD) ii) by serial sectioning and subsequent EBSP mapping of entire circular 2D sample sections; 50 sections are mapped In total 333 grains are reconstructed. It is found that the 3D grain morphologies can be quite complex in particular for the larger grains, the number of neighbours varies significantly and values above 20 are not unusual. When the results from the 2 methods are compared, it is found that the crystallographic agreement is very good and within experimental uncertainties. Slightly more significant differences are found when the reconstructed grain morphologies are compared. Reasons for this are discussed.


Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.


Author(s):  
L. T. Germinario

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.


Author(s):  
J. H. Resau ◽  
N. Howell ◽  
S. H. Chang

Spinach grown in Texas developed “yellow spotting” on the peripheral portions of the leaves. The exact cause of the discoloration could not be determined as there was no evidence of viral or parasitic infestation of the plants and biochemical characterization of the plants did not indicate any significant differences between the yellow and green leaf portions of the spinach. The present study was undertaken using electron microscopy (EM) to determine if a micro-nutrient deficiency was the cause for the discoloration.Green leaf spinach was collected from the field and sent by express mail to the EM laboratory. The yellow and equivalent green portions of the leaves were isolated and dried in a Denton evaporator at 10-5 Torr for 24 hrs. The leaf specimens were then examined using a JEOL 100 CX analytical microscope. TEM specimens were prepared according to the methods of Trump et al.


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