Texture of Polycrystalline MoSxThin Films Magnetron Sputtered from a Metallic Target in Ar-H2S Atmospheres

2002 ◽  
Vol 721 ◽  
Author(s):  
Volkmar Weiß ◽  
Rainald Mientus ◽  
Klaus Ellmer
Keyword(s):  
Gas Flow ◽  
Film Growth ◽  
Bragg Reflection ◽  
X Ray Diffraction ◽  
Avrami Model ◽  
X Ray ◽  
Si Substrates ◽  
Wide Range ◽  
Diffraction Patterns ◽  
Kinetic Calculations

AbstractThe textured film growth of polycrystalline MoSxfilms on Si substrates deposited by reactive magnetron sputtering with H2S from a molybdenum target has been investigated. Over a wide range of gas flow ratios FH2S/(FH2S+FAr) from 1% to 75% only x-ray diffraction patterns of randomly stacked S-Mo-S layers of the MoS2phase were detected which indicates turbostratic growth of the van-der-Waals layers comparable to the growth of graphite at low temperatures. The extended distance of the c-lattice planes depends on the sputtering conditions and can also be explained by the turbostratic model. Low deposition rates and high substrate temperatures improved the quality of the films towards the requested (001) texture and low c-lattice strain. The results from the in situ-energy dispersive x-ray diffraction (EDXRD) technique using synchrotron radiation allowed kinetic calculations of the time dependent behaviour of the peak area of the (0 0 21) Bragg reflection signals according to the Johnson-Mehl-Avrami model. They revealed that the grain growth is restricted in dimensions if a completed nucleation is assumed.

scholarly journals Simultaneous Multi-Bragg Peak Coherent X-ray Diffraction Imaging

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 312
Author(s):  
Florian Lauraux ◽  
Stéphane Labat ◽  
Sarah Yehya ◽  
Marie-Ingrid Richard ◽  
Steven J. Leake ◽  
...  
Keyword(s):  
Bragg Reflection ◽  
Volume Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Substrate ◽  
In Series ◽  
Diffraction Imaging ◽  
Diffraction Patterns ◽  
Lattice Planes ◽  
Oriented Parallel

The simultaneous measurement of two Bragg reflections by Bragg coherent X-ray diffraction is demonstrated on a twinned Au crystal, which was prepared by the solid-state dewetting of a 30 nm thin gold film on a sapphire substrate. The crystal was oriented on a goniometer so that two lattice planes fulfill the Bragg condition at the same time. The Au 111 and Au 200 Bragg peaks were measured simultaneously by scanning the energy of the incident X-ray beam and recording the diffraction patterns with two two-dimensional detectors. While the former Bragg reflection is not sensitive to the twin boundary, which is oriented parallel to the crystal–substrate interface, the latter reflection is only sensitive to one part of the crystal. The volume ratio between the two parts of the twinned crystal is about 1:9, which is also confirmed by Laue microdiffraction of the same crystal. The parallel measurement of multiple Bragg reflections is essential for future in situ and operando studies, which are so far limited to either a single Bragg reflection or several in series, to facilitate the precise monitoring of both the strain field and defects during the application of external stimuli.

2D X-ray diffraction and molecular modelling of the crystalline structure of polyesters under uniaxial stress

2021 ◽  
pp. 096739112199822
Author(s):  
Ahmed I Abou-Kandil ◽  
Gerhard Goldbeck
Keyword(s):  
Crystalline Structure ◽  
Molecular Modelling ◽  
Three Dimensional ◽  
Uniaxial Stress ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
Modelling Techniques ◽  
Diffraction Patterns

Studying the crystalline structure of uniaxially and biaxially drawn polyesters is of great importance due to their wide range of applications. In this study, we shed some light on the behaviour of PET and PEN under uniaxial stress using experimental and molecular modelling techniques. Comparing experiment with modelling provides insights into polymer crystallisation with extended chains. Experimental x-ray diffraction patterns are reproduced by means of models of chains sliding along the c-axis leading to some loss of three-dimensional order, i.e. moving away from the condition of perfect register of the fully extended chains in triclinic crystals of both PET and PEN. This will help us understand the mechanism of polymer crystallisation under uniaxial stress and the appearance of mesophases in some cases as discussed herein.

Algorithms for the calculation of X-ray diffraction patterns from finite element data

2010 ◽  
Vol 43 (6) ◽  
pp. 1287-1299 ◽  
Author(s):  
E. Wintersberger ◽  
D. Kriegner ◽  
N. Hrauda ◽  
J. Stangl ◽  
G. Bauer
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Point Of View ◽  
X Ray Diffraction ◽  
Displacement Fields ◽  
X Ray ◽  
Si Substrates ◽  
Diffraction Patterns ◽  
Simulation Point ◽  
Ccd Detectors

A set of algorithms is presented for the calculation of X-ray diffraction patterns from strained nanostructures. Their development was triggered by novel developments in the recording of scattered intensity distributions as well as in simulation practice. The increasing use of two-dimensional CCD detectors in X-ray diffraction experiments, with which three-dimensional reciprocal-space maps can be recorded in a reasonably short time, requires efficient simulation programs to compute one-, two- and three-dimensional intensity distributions. From the simulation point of view, the finite element method (FEM) has become the standard tool for calculation of the strain and displacement fields in nanostructures. Therefore, X-ray diffraction simulation programs must be able to handle FEM data properly. The algorithms presented here make use of the deformation fields calculated on a mesh, which are directly imported into the calculation of diffraction patterns. To demonstrate the application of the developed algorithms, they were applied to several examples such as diffraction data from a dislocated quantum dot, from a periodic array of dislocations in a PbSe epilayer grown on a PbTe pseudosubstrate, and from ripple structures at the surface of SiGe layers deposited on miscut Si substrates.

scholarly journals Iron-containing phases in metallurgical and coke dusts as well as in bog iron ore

Nukleonika ◽  
2017 ◽  
Vol 62 (2) ◽  
pp. 187-195 ◽  
Author(s):  
Tadeusz Szumiata ◽  
Marzena Rachwał ◽  
Tadeusz Magiera ◽  
Katarzyna Brzózka ◽  
Małgorzata Gzik-Szumiata ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Spinel Structure ◽  
Iron Ore ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineral Phases ◽  
Coke Plants ◽  
Wide Range ◽  
Specific Magnetic Susceptibility ◽  
Diffraction Patterns

Abstract Several samples of dusts from steel and coke plants (collected mostly with electro filters) were subjected to the investigation of content of mineral phases in their particles. Additionally, sample of bog iron ore and metallurgical slurry was studied. Next, the magnetic susceptibility of all the samples was determined, and investigations of iron-containing phases were performed using transmission Mössbauer spectrometry. The values of mass-specific magnetic susceptibility χ varied in a wide range: from 59 to above 7000 × 10−8 m-3·kg−1. The low values are determined for bog iron ore, metallurgical slurry, and coke dusts. The extremely high χ was obtained for metallurgical dusts. The Mössbauer spectra and X-ray diffraction patterns point to the presence of the following phases containing iron: hematite and oxidized magnetite (in coke and metallurgical dusts as well as metallurgical slurry), traces of magnetite fine grains fraction (in metallurgical dusts), amorphous glassy silicates with paramagnetic Fe3+ and Fe2+ ions, traces of pyrrhotite (in coke dusts), α-Fe and nonstoichiometric wüstite (in metallurgical slurry), as well as ferrihydrite nanoparticles (in bog iron ore). For individual samples of metallurgical dusts, the relative contributions of Fe2+/3+ ions in octahedral B sites and Fe2+ ions in tetrahedral A sites in magnetite spinel structure differs considerably.

Ferroelectric and Ferromagnetic Properties of Co-doped BiFeO3 Thin Films

2010 ◽  
Vol 1256 ◽  
Author(s):  
Danilo G Barrionuevo ◽  
Surinder P Singh ◽  
Ram S Katiyar ◽  
Maharaj S. Tomar
Keyword(s):  
Thin Films ◽  
Magnetic Coupling ◽  
Partial Replacement ◽  
Material System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Solution Route ◽  
Diffraction Patterns ◽  
Novel Devices

AbstractMaterials which possess electrical and magnetic coupling are of great interest for novel devices. Bi(Fe1-xCox)O3 (BFCO) material system was synthesized by solution route for various compositions and thin films were prepared by spin coating on Pt (Pt/Ti/SiO2/Si) substrates. Structural properties of the films were investigated by x-ray diffraction and Raman spectroscopy. X-ray diffraction patterns confirms intense (110) in BiFeO3 and Bi(Fe1-xCox)O3 with rhombohedra distorted perovskite structure without impure phase. Bi(Fe1-xCox)O3 films show week ferroelectric polarization and ferromagnetism at room temperature. Ferroelectric and ferromagnetic coupling could be attributed to the elimination of oxygen vacancies and increased stress in the crystal structure by partial replacement of Fe2+ ion by Co2+ ion.

scholarly journals Structural and In Situ X-ray Diffraction Study of Hydrogenation of CaxMg1−xNi2 (0 ≤ x ≤ 1)

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 47
Author(s):  
Zia Ur Rehman ◽  
Mohsan Nawaz ◽  
Hameed Ullah ◽  
Pervaiz Ahmad ◽  
Mayeen Uddin Khandaker ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Powder Diffraction ◽  
Gas Flow ◽  
Hydrogen Gas ◽  
Laves Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Phase Type ◽  
Diffraction Patterns

In the quasi-binary system CaNi2-MgNi2 solid-solutions CaxMg1−xNi2 (0 ≤ x ≤ 1) were prepared from the elements. They crystallize in the hexagonal Laves phase type (MgNi2, C36) for x ≤ 0.33 (P63/mmc, a = 482.51(7) pm, c = 1582.1(3) pm for x = 0, a = 482.59 (3), c = 1583.1(1) for x = 0.33) and in the cubic Laves phase type (MgCu2, C15) for 0.33 < x (Fd−3m, a = 697.12(3) pm for x = 0.5, a = 705.11(2) pm for x = 0.67, a = 724.80(2) pm for x = 1). After hydrogenation in an autoclave the X-ray diffraction patterns changed completely. Reflections assigned to CaNiH3, and Ni and Rietveld refinement confirmed this. The hydrogenation properties of CaxMg1−xNi2 (0 ≤ x ≤ 1) compounds were also studied in situ by X-ray powder diffraction. In situ X-ray powder diffraction of CaxMg1−xNi2 (0 ≤ x ≤ 1) compounds under 0.3 MPa hydrogen gas flow (15 sccm), data collected on a Rigaku SmartLab diffractometer in an Anton Paar XRK 900 Reactor Chamber using Cu-Kα1 radiation. Scanning electron microscopy and EDX spectroscopy confirmed the entitled materials and elemental composition, respectively. From the Transmission electron microscopy and Selected area electron diffraction concluded that the CaxMg1−xNi2 (0 ≤ x ≤ 1) compounds were crystalline.

Further studies of low-angle X-ray diffraction patterns of collagen

1959 ◽  
Vol 252 (1269) ◽  
pp. 197-216 ◽  
Keyword(s):  
Electron Microscopy ◽  
Density Distribution ◽  
Heavy Atom ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heavy Atoms ◽  
Density Distributions ◽  
Wide Range ◽  
Diffraction Patterns

Experiments were carried out on the drying of collagen fibres in vacuo at temperatures up to 200°C. Low-angle X-ray diffraction patterns of material so treated differed markedly from those of collagen dried in vacuo at room temperature, which invalidates the comparison of the latter with density distributions observed by electron microscopy. One-dimensional Patterson functions plotted for a wide range of protein hydration, together with some evidence from electron microscopy, provided helpful pointers to the density distribution in dry collagen, and strong evidence in support of a model for wet collagen consisting of a rectangular density distribution function, such that each period along the fibril has a band of higher density and an interband of lower density. The width of the band was found to be 0·46 of the period by making use of results obtained by ‘staining’ the fibres with heavy atoms. This model of the wet fibres, and the use of difference Patterson functions, made possible the elucidation of the effects of staining with silver nitrate, iodine, phosphotungstic acid, and osmium tetroxide. The major features of the distributions of these stains could be deter­mined with results consistent with the observations of electron microscopy, for those stains detectable by this means. The diffraction method was successful in detecting heavy-atom staining not visible in the electron microscope. Each of the stains considered gave somewhat similar staining patterns, a prominent feature of which was a pair of dense bands 0·8 d ( d being half the collagen period) apart, at the ends of the wet collagen band. Most of the iodine which entered these particular sites was very easily removed, but some of it was more firmly bound in these and other positions.

X-ray diffraction studies of solid solutions of Cr-, Mn-, Fe-, Co-, and Ni-containing transition metal spinel oxides

1995 ◽  
Vol 10 (3) ◽  
pp. 214-220 ◽  
Author(s):  
G. C. Allen ◽  
K. R. Hallam ◽  
J. A. Jutson
Keyword(s):  
Transition Metal ◽  
Metal Oxide ◽  
Solid Solutions ◽  
Cell Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
Spinel Oxides ◽  
Steel Surfaces ◽  
Diffraction Patterns

A wide range of transition metal oxide solid solutions have been prepared and characterised using powder X-ray diffraction (MnxCo1−xFe2O4, FexCo1−xFe2O4, NixCo1−xFe2O4, FeFexCr2−xO4, MnFexCr2−xO4, MnxFe1−xCr2O4, MnxFe1−xFe2O4, NixFe1−xFe2O4). Calibration curves have been obtained relating oxide composition to unit cell parameter or d spacing. From these curves it is possible to identify the composition of oxides formed on steel surfaces in varied industrial environments. Even when poor diffraction patterns are obtained and little sample is available, an estimate of composition can be made.

Coherent X-ray diffraction imaging meets ptychography to study core-shell-shell nanowires

MRS Advances ◽  
2018 ◽  
Vol 3 (39) ◽  
pp. 2317-2322 ◽  
Author(s):  
A. Davtyan ◽  
V. Favre-Nicolin ◽  
R. B. Lewis ◽  
H. Küpers ◽  
L. Geelhaar ◽  
...  
Keyword(s):  
Phase Retrieval ◽  
Bragg Reflection ◽  
Rotational Symmetry ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Bottom Part ◽  
X Ray ◽  
Structural Homogeneity ◽  
Diffraction Imaging ◽  
Diffraction Patterns

AbstractWe report on the results of coherent X-ray diffraction imaging (CXDI) and ptychography measurements of two individual core-shell-shell GaAs/(In,Ga)As/GaAs nanowires (NWs) grown by molecular beam epitaxy (MBE) on patterned Si(111) substrate. CXDI at the axial GaAs 111 Bragg reflection was applied at different positions along the NW axis in order to characterize the NWs in terms of structural homogeneity along the radial directions. At each positon 3D reciprocal space maps have been recoded and inverted using phase retrieval algorithms. The CXDI were complemented by 2D ptychography measurements at GaAs 111 Bragg reflection probing the same NWs with respect to their structural homogeneity. Both methods provide structural homogeneity for NW1 and NW2 except at the bottom part of the NWs. In case of NW2 CXDI and ptychography show changes in the structure of the top part of the NW indicated by 60° rotation of the indicated three-fold rotational symmetry in the observed diffraction patterns and changes in the strain field reconstructed from ptychography.

Micropatterned Arrays of ZnSe Nanospheres as Antireflection Coatings

2014 ◽  
Vol 67 (10) ◽  
pp. 1427 ◽  
Author(s):  
S. Sasi Florence ◽  
Priyanka Sachan ◽  
Raju Kumar Gupta ◽  
Rita John ◽  
Umadevi Mahalingam
Keyword(s):  
Low Cost ◽  
Gold Catalyst ◽  
Antireflection Coatings ◽  
Photovoltaic Devices ◽  
X Ray Diffraction ◽  
Large Area ◽  
X Ray ◽  
Si Substrates ◽  
Self Assembled ◽  
Diffraction Patterns

In this work, we demonstrate deposition of micro-arrays of ZnSe nanospheres on Si (100) substrate using simple thermal evaporation on a self-assembled sacrificial polystyrene (PS) mask. The results have been compared with the deposition on unpatterned gold catalyst- and SU-8 (negative photoresist)-coated Si substrates. The deposited ZnSe nanospheres properties were characterised by X-ray diffraction, atomic force microscopy (AFM), scanning electron microscopy (SEM), Raman, photoluminescence, and UV-vis spectroscopies. The X-ray diffraction patterns of the films exhibited reflection corresponding to the cubic (111) phase and showed polycrystallinity with a cubic (zinc blende) structure. The SEM and AFM images indicated that the particles were well dispersed and spherical in shape. The micro-arrays of ZnSe nanospheres on a self-assembled sacrificial PS mask showed excellent structural, morphological, and optical properties and demonstrated its usage in photovoltaic devices as an improved superior antireflective coating. The reflectance of the micro-arrays of ZnSe nanospheres on a self-assembled sacrificial PS mask decreased to nearly half of that of the ZnSe nanospheres fabricated on Au- and SU-8-coated Si substrates in the range of 300–800 nm. Due to the well aligned and patterned surfaces, these noble textured ZnSe nanospheres may be suitable for low cost, large area photovoltaic devices and other antireflection applications.

Sign in / Sign up

Export Citation Format

Share Document