Layer thickness determinations with X-ray diffraction

1989 ◽  
Vol 22 (2) ◽  
pp. 150-154 ◽  
Author(s):  
D. E. Anderson ◽  
W. J. Thomson
Keyword(s):  
Absorption Coefficient ◽  
Layer Thickness ◽  
Single Equation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Practical Difficulty ◽  
Diffusion Limited ◽  
Crystalline Substrate ◽  
New Equation

A new equation involving an absorption coefficient is presented for calculating the thickness of a layer of a crystalline specimen deposited on a crystalline substrate. This new equation is particularly applicable to in situ X-ray diffraction studies of diffusion-limited kinetics; it is demonstrated that the practical difficulty of optimally partitioning count time between the peak of the substrate and peak of the layered specimen is overcome by making use of all available data in this single equation. This can result in more precise thickness determinations for intermediate specimen thicknesses than would be possible with either of the existing methods.

Amorphous Phase Formation in Solid State Reactions of Layered Nickel Zirconium Films

1984 ◽  
Vol 37 ◽  
Author(s):  
Bruce M. Clemens ◽  
Jeffrey C. Buchholz
Keyword(s):  
Solid State ◽  
Layer Thickness ◽  
Amorphous Phase ◽  
Amorphous Material ◽  
Depth Profiling ◽  
Layer Growth ◽  
Solid State Reactions ◽  
X Ray Diffraction ◽  
X Ray

AbstractFormation of an amorphous zirconium-nickel phase by solid state reaction of a layered crystalline structure has been studied by in-situ resistivity, x-ray diffraction, and Auger depth profiling. The reaction was studied as a function of layer thickness and reaction temperature.Samples with a layer thickness of less than 4 atomic planes had x-ray diffraction spectra with one broad maximum characteristic of amorphous material. As the layer thickness increased, the maximum broadened and separated into two resolved peaks corresponding to crystalline nickel and zirconium. These structures were transformed to an amorphous nickel-zirconium alloy by an anneal at temperatures below the crystallization temperature of the amorphous phase. The reaction occured by a layer growth process, where the thickness of the layer evolved linearly with the square root of time.

scholarly journals Control of Metal–Organic Framework Crystallization by Metastable Intermediate Pre-equilibrium Species

2018 ◽  
Author(s):  
Hamish Yeung ◽  
adam sapnik ◽  
Felicity Massingberd-Mundy ◽  
Michael W. Gaultois ◽  
Yue Wu ◽  
...  
Keyword(s):  
Network Formation ◽  
Metal Organic Framework ◽  
Size Composition ◽  
Formation Mechanisms ◽  
New Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffusion Limited ◽  
Metal Organic

<p>The phenomenon of crystallization is poorly understood and yet is critical to the design of new materials, such as metal-organic frameworks (MOFs), for which predictive formation mechanisms remain elusive. We report a tandem in situ X-ray diffraction and pH investigation into the prototypical MOF, ZIF-8, in which it is found that the crystallization mechanism changes from phase boundary-limited to diffusion-limited across the course of each reaction, and crystallization rates decrease with increasing concentration. These counterintuitive observations are explained using a non-linear pre-equilibrium model, in which network formation depends on the rates of Zn-imidazole coordination and imidazole deprotonation. Whilst assembly of under-coordinated species is associative and fast, over-coordinated species act to inhibit network formation. The work rationalises apparent contradictions between previous studies and opens up new opportunities for the creation of MOFs with control over particle size, composition and local structure.</p>

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

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.

In-situ Investigation of Bainite Formation with fast X-Ray Diffraction (iXRD)

2017 ◽  
Vol 72 (6) ◽  
pp. 355-364
Author(s):  
A. Kopp ◽  
T. Bernthaler ◽  
D. Schmid ◽  
G. Ketzer-Raichle ◽  
G. Schneider
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Investigation

Texture Evolution Under Fast Heating and Cooling Rates of Zirconium Alloys Studied In-Situ by Synchrotron X-Ray Diffraction

2020 ◽  
Author(s):  
Chi-Toan Nguyen ◽  
Alistair Garner ◽  
Javier Romero ◽  
Antoine Ambard ◽  
Michael Preuss ◽  
...  
Keyword(s):  
Texture Evolution ◽  
Zirconium Alloys ◽  
X Ray Diffraction ◽  
Fast Heating ◽  
Cooling Rates ◽  
X Ray ◽  
Heating And Cooling

STRUCTURAL EVOLUTION OF EXCEPTIONALLY IRON-DEFICIENT HEMATITE NANOCRYSTALS AS OBSERVED BY IN SITU SYNCHROTRON X-RAY DIFFRACTION

2019 ◽  
Author(s):  
Si Athena Chen ◽  
◽  
Peter Heaney ◽  
Jeffrey E. Post ◽  
Peter J. Eng ◽  
...  
Keyword(s):  
Structural Evolution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Iron Deficient

In situ X-ray diffraction techniques as a powerful tool to study battery electrode materials

2002 ◽  
Vol 47 (19) ◽  
pp. 3137-3149 ◽  
Author(s):  
M. Morcrette ◽  
Y. Chabre ◽  
G. Vaughan ◽  
G. Amatucci ◽  
J.-B. Leriche ◽  
...  
Keyword(s):  
Electrode Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Battery Electrode

scholarly journals In-Situ Synchrotron X-ray Diffraction Investigation of Microstructural Evolutions During Low-Pressure Carburizing

2021 ◽  
Author(s):  
Ogün Baris Tapar ◽  
Jérémy Epp ◽  
Matthias Steinbacher ◽  
Jens Gibmeier
Keyword(s):  
Carbon Content ◽  
Carbon Diffusion ◽  
Low Pressure ◽  
Carbon Accumulation ◽  
Experimental Chamber ◽  
Carbide Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon Supply

AbstractAn experimental heat treatment chamber and control system were developed to perform in-situ X-ray diffraction experiments during low-pressure carburizing (LPC) processes. Results from the experimental chamber and industrial furnace were compared, and it was proven that the built system is reliable for LPC experiments. In-situ X-ray diffraction investigations during LPC treatment were conducted at the German Electron Synchrotron Facility in Hamburg Germany. During the boost steps, carbon accumulation and carbide formation was observed at the surface. These accumulation and carbide formation decelerated the further carbon diffusion from atmosphere to the sample. In the early minutes of the diffusion steps, it is observed that cementite content continue to increase although there is no presence of gas. This effect is attributed to the high carbon accumulation at the surface during boost steps which acts as a carbon supply. During quenching, martensite at higher temperature had a lower c/a ratio than later formed ones. This difference is credited to the early transformation of austenite regions having lower carbon content. Also, it was noticed that the final carbon content dissolved in martensite reduced compared to carbon in austenite before quenching. This reduction was attributed to the auto-tempering effect.

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