scholarly journals Multireflection grazing-incidence X-ray diffraction: a new approach to experimental data analysis

2019 ◽  
Vol 52 (6) ◽  
pp. 1409-1421 ◽  
Author(s):  
Marianna Marciszko-Wiąckowska ◽  
Adrian Oponowicz ◽  
Andrzej Baczmański ◽  
Miroslaw Wróbel ◽  
Ch. Braham ◽  
...  
Keyword(s):  
Experimental Data ◽  
Linear Regression ◽  
Diffraction Method ◽  
Grazing Incidence ◽  
Lattice Parameter ◽  
Test Surface ◽  
Shear Stresses ◽  
Simple Linear Regression ◽  
X Ray Diffraction ◽  
X Ray

The multireflection grazing-incidence X-ray diffraction method is used to test surface stresses at depths of several micrometres in the case of metal samples. This work presents new ways of analysing experimental data obtained by this method for Ni samples exhibiting significant elastic anisotropy of crystals. Three different methods of determining biaxial stresses and lattice parameter were compared. In the first approach, the calculations were performed using the linear least-squares method, and then two simplified procedures based on simple linear regression (weighted and non-weighted) were applied. It was found that all the tested methods give similar results, i.e. almost equal values of the determined stresses and lattice parameters and the uncertainties of their determination. The advantage of analyses based on simple linear regression is their simplicity and straightforward interpretation, enabling easy verification of the influence of the crystallographic texture and the presence of shear stresses, as well as graphical determination of the stress-free lattice parameter.

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.

scholarly journals Grazing-incidence X-ray diffraction of single GaAs nanowires at locations defined by focused ion beams

2013 ◽  
Vol 46 (4) ◽  
pp. 887-892 ◽  
Author(s):  
Genziana Bussone ◽  
Rüdiger Schott ◽  
Andreas Biermanns ◽  
Anton Davydok ◽  
Dirk Reuter ◽  
...  
Keyword(s):  
Gaas Substrate ◽  
Lattice Spacing ◽  
Molecular Beam ◽  
Grazing Incidence ◽  
Lattice Parameter ◽  
Ion Beams ◽  
Focused Ion Beams ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gaas Nanowires

Grazing-incidence X-ray diffraction measurements on single GaAs nanowires (NWs) grown on a (111)-oriented GaAs substrate by molecular beam epitaxy are reported. The positions of the NWs are intentionally determined by a direct implantation of Au with focused ion beams. This controlled arrangement in combination with a nanofocused X-ray beam allows the in-plane lattice parameter of single NWs to be probed, which is not possible for randomly grown NWs. Reciprocal space maps were collected at different heights along the NW to investigate the crystal structure. Simultaneously, substrate areas with different distances from the Au-implantation spots below the NWs were probed. Around the NWs, the data revealed a 0.4% decrease in the lattice spacing in the substrate compared with the expected unstrained value. This suggests the presence of a compressed region due to Au implantation.

Influence of Surface Roughness on the Quality of Data Obtained by Pseudo-Grazing Incidence X-Ray Diffraction

2006 ◽  
Vol 514-516 ◽  
pp. 1618-1622 ◽  
Author(s):  
Maria José Marques ◽  
J.C.P. Pina ◽  
A. Morão Dias
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Stress Gradient ◽  
Roughness Parameter ◽  
Diffraction Method ◽  
Grazing Incidence ◽  
Bragg Diffraction ◽  
X Ray Diffraction ◽  
Residual Surface Stress ◽  
X Ray

The conventional Bragg diffraction geometry, normally used to characterize the residual surface stress state, it is not suitable to evaluate surface treated materials and thin films. The X-ray path lengths through a surface layer or thin film are too short to produce adequate diffraction intensities in relation to the bulk or the substrate. Another limitation of the conventional technique appears when a residual stress gradient is present in the irradiated surface. The technique only enables the evaluation of the mean value of this gradient. In these cases, a recently proposed Pseudo-Grazing Incident X-ray Diffraction method would be better applicable. In this study, the Pseudo-Grazing Incidence X-ray Diffraction is applied to characterize the residual stress depth profiles of several AISI 4140 samples, which were prepared, by mechanical polishing and grinding, in order to present different surface roughness parameters, Ra. The experimental results lead to the conclusion that the surface roughness limits the application of the Pseudo-Grazing Incidence methodology to a minimum X-ray incident angle. This angle is the one that enables a mean X-ray penetration depth with the same order of magnitude of the sample surface roughness parameter, Ra.

scholarly journals Stress measurements by multi-reflection grazing-incidence X-ray diffraction method (MGIXD) using different radiation wavelengths and different incident angles

2017 ◽  
Vol 123 ◽  
pp. 157-166 ◽  
Author(s):  
Marianna Marciszko ◽  
Andrzej Baczmański ◽  
Chedly Braham ◽  
Mirosław Wróbel ◽  
Sebastian Wroński ◽  
...  
Keyword(s):  
Diffraction Method ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
X Ray ◽  
Stress Measurements

Interfacial Diffusion in a MOCVD Grown Barium Titanate Film

1999 ◽  
Vol 591 ◽  
Author(s):  
A. Datta ◽  
Soma Chattopadhyay ◽  
A.G. Richter ◽  
J. Kmetko ◽  
C. B. Lee
Keyword(s):  
Ferroelectric Phase Transition ◽  
Ferroelectric Phase ◽  
Grazing Incidence ◽  
Lattice Parameter ◽  
Composition Profile ◽  
Progressive Decrease ◽  
X Ray Diffraction ◽  
Interfacial Diffusion ◽  
X Ray ◽  
Film Substrate

ABSTRACTA combination of two nondestructive techniques, Grazing Incidence X-ray Reflectivity and High Resolution X-ray Diffraction, is used to study (at around 10Å resolution) the composition profile across a 500Å thick film of BaTiO3 grown epitaxially on (100) MgO by MOCVD. Results from both studies indicate diffusion of Mg to about 250Å into the film at film-substrate interface, consistent with the diffuse ferroelectric phase transition observed in this film. The lattice parameter a shows a progressive decrease as we move into the film from the interface, and an anomalously low value in the Mg-free portion of the film.

scholarly journals Residual stress analysis after machining in composite materials based on aluminum alloy with ceramic additive

Mechanik ◽  
2018 ◽  
Vol 91 (1) ◽  
pp. 28-30
Author(s):  
Jolanta Cyboroń
Keyword(s):  
Electrical Discharge Machining ◽  
Diffraction Method ◽  
Grazing Incidence ◽  
Machining Process ◽  
Abrasive Water Jet ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Subsurface Layers ◽  
The Impact

The paper presents the results of structural studies of AlSi7Mg alloy with 5% vol. addition of silicon carbide (SiC), after the machining process using the alternative method including: electrical discharge machining (EDM), abrasive water jet (AWJ) and cutting. The article presents the possibilities of measuring the impact of selected machining techniques on the surface and subsurface layers. X-ray diffraction were used to determine the level and characters of the obtained residual stresses. The article presents the X-ray diffraction method in the grazing incidence X-ray diffraction technique (GIXD) used for the practical measurement of the range of changes within the surface layer formed, as a result of interaction between the tool and the surface of the material being processed.

scholarly journals Investigation Of Helium Implanted Fe–Cr Alloys By Means Of X–Ray Diffraction And Positron Annihilation Spectroscopy

2015 ◽  
Vol 66 (6) ◽  
pp. 334-338
Author(s):  
Patrik Novák ◽  
Aleksandr Gokhman ◽  
Edmund Dobročka ◽  
Jozef Bokor ◽  
Stanislav Pecko
Keyword(s):  
Positron Annihilation ◽  
Domain Size ◽  
Surface Region ◽  
Grazing Incidence ◽  
Positron Annihilation Spectroscopy ◽  
Lattice Parameter ◽  
Implantation Dose ◽  
X Ray Diffraction ◽  
Coherent Domain Size ◽  
X Ray

Abstract X-ray diffraction (XRD) and positron annihilation spectroscopy (PAS) have been used for the characterization of the two binary alloys Fe-Cr with Cr content 2.36 and 8.39 wt%. The influence of ion implantation on these alloys was studied. Different implantation doses of helium, up to 0.5 C/cm2, were used to simulate neutron-induced damage in a sub-surface region. To characterize the damage, a lattice parameter, coherent domain size, residual stress and a crystallographic texture have been studied by grazing incidence X-ray diffraction (GIXRD). It was found out that these parameters showed a similar dependence on the implantation dose as the positron lifetime determined by positron annihilation spectroscopy.

Sign in / Sign up

Export Citation Format

Share Document