Investigation of lattice plane bending in large (0001)SiC crystals using high-energy X-ray technique

2005 ◽  
Vol 2 (4) ◽  
pp. 1288-1291 ◽  
Author(s):  
B. M. Epelbaum ◽  
Z. G. Herro ◽  
M. Bickermann ◽  
C. Seitz ◽  
A. Magerl ◽  
...  
Keyword(s):  
High Energy ◽  
Lattice Plane ◽  
X Ray ◽  
Plane Bending

Observation of Lattice Plane Bending during SiC PVT Bulk Growth Using In Situ High Energy X-Ray Diffraction

2010 ◽  
Vol 645-648 ◽  
pp. 29-32 ◽  
Author(s):  
Rainer Hock ◽  
Katja Konias ◽  
L. Perdicaro ◽  
Andreas Magerl ◽  
Philip Hens ◽  
...  
Keyword(s):  
Growth Process ◽  
Growth Front ◽  
High Energy ◽  
Lattice Plane ◽  
X Ray Diffraction ◽  
Thermally Induced ◽  
X Ray ◽  
Bulk Growth ◽  
Plane Bending

We have investigated thermally induced strain in the SiC crystal lattice during physical vapor transport bulk growth. Using high energy x-ray diffraction lattice plane bending was observed in-situ during growth. With increasing growth rate increasing lattice plane bending and, hence, strain was observed. A comparison with numerical modeling of the growth process shows that the latter is related to the heat of crystallization which needs to be dissipated from the crystal growth front. The related temperature gradient as driving force for the dissipation of the heat of crystallization causes lattice plane bending. Optimization of the growth process needs to consider such effects.

Spatial variation of lattice plane bending of 4H-SiC substrates

CrystEngComm ◽  
2017 ◽  
Vol 19 (27) ◽  
pp. 3844-3849 ◽  
Author(s):  
Yingxin Cui ◽  
Xiaobo Hu ◽  
Xuejian Xie ◽  
Rongkun Wang ◽  
Xiangang Xu
Keyword(s):  
High Resolution ◽  
Spatial Variation ◽  
Basal Plane ◽  
Lattice Plane ◽  
X Ray ◽  
Plane Bending

Basal plane bending of on- and off-axis 4H-SiC substrates was measured by high-resolution X-ray diffractometry (HRXRD).

scholarly journals Lattice-plane bending angle modulation of Mg-doped GaN homoepitaxial layer observed by X-ray diffraction topography

CrystEngComm ◽  
2019 ◽  
Vol 21 (14) ◽  
pp. 2281-2285
Author(s):  
Jaemyung Kim ◽  
Okkyun Seo ◽  
Chulho Song ◽  
Satoshi Hiroi ◽  
Yanna Chen ◽  
...  
Keyword(s):  
Lattice Plane ◽  
X Ray Diffraction ◽  
Bending Angle ◽  
X Ray ◽  
Angle Modulation ◽  
Plane Bending ◽  
Homoepitaxial Layers ◽  
Mg Doped

We have studied the lattice-plane modulation of Mg-doped GaN homoepitaxial layers by X-ray diffraction topography.

scholarly journals Determination of Temperature-Dependent Elastic Constants of Steel AISI 4140 by Use of In Situ X-ray Dilatometry Experiments

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2378
Author(s):  
Dominik Kiefer ◽  
Jens Gibmeier ◽  
Andreas Stark
Keyword(s):  
Elastic Constants ◽  
High Energy ◽  
Lattice Plane ◽  
Temperature Dependent ◽  
X Ray ◽  
Aisi 4140 ◽  
Steel Aisi ◽  
In Situ Diffraction

In situ dilatometry experiments using high energy synchrotron X-ray diffraction in transmission mode were carried out at the high energy material science beamline P07@PETRAIII at DESY (Deutsches Elektronen Synchrotron) for the tempering steel AISI 4140 at defined mechanical loading. The focus of this study was on the initial tempering state ( f e r r i t e ) and the hardened state ( m a r t e n s i t e ). Lattice strains were calculated from the 2D diffraction data for different h k l planes and from those temperature-dependent lattice plane specific diffraction elastic constants ( D E C s ) were determined. The resulting coupling terms allow for precise stress analysis for typical hypoeutectoid steels using diffraction data during heat treatment processes, that is, for in situ diffraction studies during thermal exposure. In addition, by averaging h k l specific Y o u n g ′ s m o d u l i and P o i s s o n r a t i o s macroscopic temperature-dependent elastic constants were determined. In conclusion a novel approach for the determination of phase-specific temperature-dependent DECs was suggested using diffraction based dilatometry that provides more reliable data in comparison to conventional experimental procedures. Moreover, the averaging of lattice plane specific results from in situ diffraction analysis supply robust temperature-dependent macroscopic elastic constants for martensite and ferrite as input data for heat treatment process simulations.

High-purity Ge x-ray detectors: Sensitivity factors and usefulness

1990 ◽  
Vol 48 (2) ◽  
pp. 548-548
Author(s):  
E. B. Steel
Keyword(s):  
High Purity ◽  
High Energy ◽  
Quantitative Chemical Analysis ◽  
Detector Performance ◽  
X Ray ◽  
Detector Sensitivity ◽  
Specimen Holder ◽  
Many Instruments ◽  
Charge Resolution ◽  
Sensitivity Factors

High Purity Germanium (HPGe) x-ray detectors are now commercially available for the analytical electron microscope (AEM). The detectors have superior efficiency at high x-ray energies and superior resolution compared to traditional lithium-drifted silicon [Si(Li)] detectors. However, just as for the Si(Li), the use of the HPGe detectors requires the determination of sensitivity factors for the quantitative chemical analysis of specimens in the AEM. Detector performance, including incomplete charge, resolution, and durability has been compared to a first generation detector. Sensitivity factors for many elements with atomic numbers 10 through 92 have been determined at 100, 200, and 300 keV. This data is compared to Si(Li) detector sensitivity factors.The overall sensitivity and utility of high energy K-lines are reviewed and discussed. Many instruments have one or more high energy K-line backgrounds that will affect specific analytes. One detector-instrument-specimen holder combination had a consistent Pb K-line background while another had a W K-line background.

Designing high-resolution slow scan CCD-based TEM camera systems

1992 ◽  
Vol 50 (2) ◽  
pp. 946-947
Author(s):  
James F. Mancuso ◽  
William B. Maxwell ◽  
Russell E. Camp ◽  
Mark H. Ellisman
Keyword(s):  
Fiber Optics ◽  
Ccd Camera ◽  
High Energy ◽  
Phosphor Layer ◽  
X Ray ◽  
Light Production ◽  
Camera Systems ◽  
X Ray Imaging ◽  
Electron Image ◽  
Scintillating Fiber

The imaging requirements for 1000 line CCD camera systems include resolution, sensitivity, and field of view. In electronic camera systems these characteristics are determined primarily by the performance of the electro-optic interface. This component converts the electron image into a light image which is ultimately received by a camera sensor.Light production in the interface occurs when high energy electrons strike a phosphor or scintillator. Resolution is limited by electron scattering and absorption. For a constant resolution, more energy deposition occurs in denser phosphors (Figure 1). In this respect, high density x-ray phosphors such as Gd2O2S are better than ZnS based cathode ray tube phosphors. Scintillating fiber optics can be used instead of a discrete phosphor layer. The resolution of scintillating fiber optics that are used in x-ray imaging exceed 20 1p/mm and can be made very large. An example of a digital TEM image using a scintillating fiber optic plate is shown in Figure 2.

The Basic Physical Principles of Ion, Electron, and X-Ray Detectors and Their Application to Microanalysis

1985 ◽  
Vol 43 ◽  
pp. 154-157
Author(s):  
A.J. Tousimis
Keyword(s):  
Ion Beam ◽  
Depth Resolution ◽  
Sample Surface ◽  
High Energy ◽  
X Rays ◽  
X Ray ◽  
Electrons And Ions ◽  
Spatial Depth ◽  
Minimum Surface Area ◽  
Physical Principles

An integral and of prime importance of any microtopography and microanalysis instrument system is its electron, x-ray and ion detector(s). The resolution and sensitivity of the electron microscope (TEM, SEM, STEM) and microanalyzers (SIMS and electron probe x-ray microanalyzers) are closely related to those of the sensing and recording devices incorporated with them.Table I lists characteristic sensitivities, minimum surface area and depth analyzed by various methods. Smaller ion, electron and x-ray beam diameters than those listed, are possible with currently available electromagnetic or electrostatic columns. Therefore, improvements in sensitivity and spatial/depth resolution of microanalysis will follow that of the detectors. In most of these methods, the sample surface is subjected to a stationary, line or raster scanning photon, electron or ion beam. The resultant radiation: photons (low energy) or high energy (x-rays), electrons and ions are detected and analyzed.

Utilisation of High-Energy Heat Sources in Magnesium Alloy Surface Layer Treatment

2013 ◽  
Vol 58 (2) ◽  
pp. 619-624 ◽  
Author(s):  
M. Szafarska ◽  
J. Iwaszko ◽  
K. Kudła ◽  
I. Łegowik
Keyword(s):  
Surface Layer ◽  
Magnesium Alloy ◽  
Physicochemical Properties ◽  
Treatment Effectiveness ◽  
High Energy ◽  
Alloy Surface ◽  
Heat Sources ◽  
X Ray ◽  
Additional Equipment ◽  
Alloy Surface Layer

The main aim of the study was the evaluation of magnesium alloy surface treatment effectiveness using high-energy heat sources, i.e. a Yb-YAG Disk Laser and the GTAW method. The AZ91 and AM60 commercial magnesium alloys were subject to surface layer modification. Because of the physicochemical properties of the materials studied in case of the GTAW method, it was necessary to provide the welding stand with additional equipment. A novel two-torch set with torches operating in tandem was developed within the experiment. The effectiveness of specimen remelting using a laser and the GTAW method was verified based on macro- and microscopic examinations as well as in X-ray phase analysis and hardness measurements. In addition, the remelting parameters were optimised. The proposed treatment methodology enabled the achieving of the intended result and effective modification of a magnesium alloy surface layer.

Mesoscale structural characterization within bulk materials by high-energy X-ray microdiffraction

AIAA Journal ◽  
2001 ◽  
Vol 39 ◽  
pp. 919-923
Author(s):  
U. Lienert ◽  
H. F. Poulsen ◽  
A. Kvick
Keyword(s):  
Structural Characterization ◽  
High Energy ◽  
Bulk Materials ◽  
X Ray
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