Single Crystal Time-of-Flight Neutron Diffraction

2002 ◽  
Vol 85 (4) ◽  
pp. 297-318 ◽  
Author(s):  
J. Peters ◽  
W. Jauch
Keyword(s):  
Neutron Diffraction ◽  
Single Crystal ◽  
Three Dimensional ◽  
Time Of Flight ◽  
Diffraction Method ◽  
Neutron Sources ◽  
X Ray ◽  
Sorting Technique ◽  
History Of ◽  
Neutron Diffraction Method

The last century has seen a large development in diffraction techniques. The time-of-flight neutron diffraction method is now so advanced that it provides high precision results for position and thermal parameters, which are complementary to other diffraction results from X-ray sources. Here we review the history of neutron sources, the difficulties encountered with the time-of-flight technique and an outlook for applications. In this context, we will show the limitations of existing neutron sources and the expected advantages of new spallation neutron sources. An overview of all corrections to be taken into account with the wavelength-sorting technique will be presented as well as actual results, how to overcome such problems, and the special difficulty of integration of three-dimensional Bragg peaks.

Application of X-Ray and Neutron Diffraction Methods to Reliability Evaluation of Structural Components and Electronic Device

2005 ◽  
Vol 490-491 ◽  
pp. 19-27
Author(s):  
Makoto Hayashi ◽  
Shinobu Okido
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Electronic Device ◽  
Diffraction Method ◽  
Deep Penetration ◽  
Structural Components ◽  
X Ray Diffraction ◽  
Actual Structure ◽  
X Ray ◽  
Neutron Diffraction Method

In the X-ray diffraction method, the diffraction intensity, the half-value width, the residual stress and the amount of residual austenitic phase can be measured. By using these parameters, the quality, the mechanical properties and the fatigue strength of materials, the remaining life of fatigue and creep can be evaluated. While the X-ray study has been widely performed for the various kinds of industrial fields in the laboratory, the applications to the actual structure and components have not so many. However, the small size X-ray residual stress analyzer, the position sensitive detector and the micro area diffraction apparatus have been developed for these twenty years. Thus the X-ray diffraction methods have been variously applied to the industrial fields. The X-ray diffraction methods were used to be applied for the large scale structures and machine parts, but recently applied to the semi-conductor fields. On the other hand, the neutron diffraction method has been introduced to measure the residual stresses in the internals of components because of its deep penetration depth. Based on the experiences of X-ray diffraction method, the various kinds of techniques have been proposed. In this paper, the applications of X-ray and neutron diffraction method to the reliability evaluations of structural components and the electronic devices are described.

Characterization of the three-dimensional residual stress distribution in SiC bulk crystals by neutron diffraction

CrystEngComm ◽  
2017 ◽  
Vol 19 (43) ◽  
pp. 6527-6532 ◽  
Author(s):  
Xuejian Xie ◽  
Xiaobo Hu ◽  
Xiufang Chen ◽  
Fafu Liu ◽  
Xianglong Yang ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Neutron Diffraction ◽  
Three Dimensional ◽  
Diffraction Method ◽  
Residual Stress Distribution ◽  
Bulk Crystals ◽  
First Time ◽  
Neutron Diffraction Method

The neutron diffraction method was adopted to study the three-dimensional residual stress distribution in SiC bulk crystals for the first time.

Neutron diffraction measurements of residual stress and plastic deformation in an aluminium alloy weld

1988 ◽  
Vol 23 (4) ◽  
pp. 201-211 ◽  
Author(s):  
D J Smith ◽  
R H Leggatt ◽  
G A Webster ◽  
H J Macgillivray ◽  
P J Webster ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Plastic Strain ◽  
Residual Stresses ◽  
Aluminium Alloy ◽  
Three Dimensional ◽  
Diffraction Method ◽  
Accurate Indication ◽  
Neutron Diffraction Technique ◽  
Neutron Diffraction Method ◽  
Alloy Weld

The neutron diffraction technique for measuring residual stresses non-destructively in an aluminium alloy weld has been examined. Calibration experiments have been performed to determine the influence of prior plastic strain and surface effects. Comparisons have also been made with strain gauge methods using the destructive block removal and layering technique for measuring the residual stresses. It has been shown that the neutron diffraction method gives an accurate indication of the three dimensional stress distribution present in a weld and that it can also be employed to estimate the amount of prior plastic strain encountered.

Modulated corrugations in the crystal structure of the superconductor CaAlSi

2006 ◽  
Vol 62 (5) ◽  
pp. 710-718 ◽  
Author(s):  
Karine M. Sparta ◽  
Ralf Müller ◽  
Michael Merz ◽  
Georg Roth ◽  
Peter Adelmann ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Thermal History ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Modulated Structure ◽  
X Ray ◽  
Modulated Phases ◽  
Modulated Structures ◽  
History Of

We report the crystal structure analyses of CaAlSi from single-crystal and powder X-ray diffraction and the existence of two commensurately modulated phases, a sixfold and a fivefold modulated structure. This polymorphism seems to be correlated to the thermal history of the sample. We describe both modulated structures using a three-dimensional and a (3 + 1)-dimensional formalism.

scholarly journals An investigation of polyhedral deformation in two mixed-metal diarsenates: SrZnAs2O7and BaCuAs2O7

2015 ◽  
Vol 71 (4) ◽  
pp. 330-337 ◽  
Author(s):  
Sabina Kovač ◽  
Ljiljana Karanović ◽  
Tamara Đorđević
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
General Formula ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Open Framework ◽  
Geometrical Characteristics ◽  
Barium Copper

Two isostructural diarsenates, SrZnAs2O7(strontium zinc diarsenate), (I), and BaCuAs2O7[barium copper(II) diarsenate], (II), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. The three-dimensional open-framework crystal structure consists of corner-sharingM2O5(M2 = Zn or Cu) square pyramids and diarsenate (As2O7) groups. Each As2O7group shares its five corners with five differentM2O5square pyramids. The resulting framework delimits two types of tunnels aligned parallel to the [010] and [100] directions where the large divalent nine-coordinatedM1 (M1 = Sr or Ba) cations are located. The geometrical characteristics of theM1O9,M2O5and As2O7groups of known isostructural diarsenates, adopting the general formulaM1IIM2IIAs2O7(M1II= Sr, Ba, Pb;M2II= Mg, Co, Cu, Zn) and crystallizing in the space groupP21/n, are presented and discussed.

scholarly journals Growth of sillenite Bi12FeO20 single crystals: structural, thermal, optical, photocatalytic features and first principle calculations

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Durga Sankar Vavilapalli ◽  
Ambrose A. Melvin ◽  
F. Bellarmine ◽  
Ramanjaneyulu Mannam ◽  
Srihari Velaga ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Photoelectron Spectroscopy ◽  
Diffraction Method ◽  
Lattice Parameter ◽  
First Principle ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Principle Calculations ◽  
Photodegradation Efficiency

AbstractIdeal sillenite type Bi12FeO20 (BFO) micron sized single crystals have been successfully grown via inexpensive hydrothermal method. The refined single crystal X-ray diffraction data reveals cubic Bi12FeO20 structure with single crystal parameters. Occurrence of rare Fe4+ state is identified via X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The lattice parameter (a) and corresponding molar volume (Vm) of Bi12FeO20 have been measured in the temperature range of 30–700 °C by the X-ray diffraction method. The thermal expansion coefficient (α) 3.93 × 10–5 K−1 was calculated from the measured values of the parameters. Electronic structure and density of states are investigated by first principle calculations. Photoelectrochemical measurements on single crystals with bandgap of 2 eV reveal significant photo response. The photoactivity of as grown crystals were further investigated by degrading organic effluents such as Methylene blue (MB) and Congo red (CR) under natural sunlight. BFO showed photodegradation efficiency about 74.23% and 32.10% for degrading MB and CR respectively. Interesting morphology and microstructure of pointed spearhead like BFO crystals provide a new insight in designing and synthesizing multifunctional single crystals.

Residual Stress Evaluation of Ni Based Weld Metal Using Neutron Diffraction Method

2006 ◽  
Vol 524-525 ◽  
pp. 697-702 ◽  
Author(s):  
Shinobu Okido ◽  
Hiroshi Suzuki ◽  
K. Saito
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Neutron Diffraction ◽  
Weld Metal ◽  
Diffraction Method ◽  
Fem Analysis ◽  
Butt Weld ◽  
Stress Evaluation ◽  
Neutron Diffraction Method

Residual stress generated in Type-316 austenitic stainless steel butt-weld jointed by Inconel-182 was measured using a neutron diffraction method and compared with values calculated using FEM analysis. The measured values of Type-316 austenitic stainless steel as base material agreed well with the calculated ones. The diffraction had high intensity and a sharp profile in the base metal. However, it was difficult to measure the residual stress at the weld metal due to very weak diffraction intensities. This phenomenon was caused by the texture in the weld material generated during the weld procedure. As a result, this texture induced an inaccurate evaluation of the residual stress. Procedures for residual stress evaluation to solve this textured material problem are discussed in this paper. As a method for stress evaluation, the measured strains obtained from a different diffraction plane with strong intensity were modified with the ratio of the individual elastic constant. The values of residual stress obtained using this method were almost the same as those of the standard method using Hooke’s law. Also, these residual stress values agreed roughly with those from the FEM analysis. This evaluation method is effective for measured samples with a strong texture like Ni-based weld metal.

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