White-Beam Transmission Characterization of Texture in Mo Thin Films and Mo/W Multilayers

1993 ◽  
Vol 317 ◽  
Author(s):  
Marc Vill ◽  
S. G. MALHOTRA ◽  
Z. Rek ◽  
S. M. Yalisove ◽  
J. C. Bilello
Keyword(s):  
Growth Direction ◽  
X Rays ◽  
X Ray Diffraction ◽  
Orientation Data ◽  
X Ray ◽  
White Beam ◽  
Out Of Plane ◽  
Transmission Study ◽  
Beam Transmission ◽  
Plane Diffraction

ABSTRACTSynchrotron white-beam (polychromatic) x-ray radiation was used in a transmission Laue study of texture in monolithic mo films and Mo/W Multilayers. High intensity synchrotron radiation permits x-ray diffraction study of mo specimens >100μm in thickness, while 6μm is the practical thickness limit for a transmission study using a rotating anode x-ray source. The transmission Laue technique permits the collection of preferred orientation data from several families of diffracting planes on one photographic exposure. Polychromatic x-rays facilitate collection of diffraction information from a range of planar orientations without altering the orientation of the sample with respect to the incident x-ray beam. The texture information from a 35μm thick monolithic mo film and a 31μm thick multilayer of mo and W is presented. Two-fold symmetry seen in the {211} plane diffraction ring of the multilayer demonstrated both an in-plane and out-of-plane texture with a <110> growth direction. Three fold symmetry seen in the {310} and {222} plane diffraction rings of the monolithic mo film demonstrated both in-plane and out-of-plane texture which suggests a <111> growth direction.

Generalized grazing-incidence-angle X-ray diffraction (G-GIXD) using image plates

1998 ◽  
Vol 5 (3) ◽  
pp. 488-490 ◽  
Author(s):  
Yasuo Takagi ◽  
Masao Kimura
Keyword(s):  
Incidence Angle ◽  
Incident Beam ◽  
Grazing Incidence ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface And Interface ◽  
Out Of Plane ◽  
Grazing Incidence Angle ◽  
Interface Layers

A new and more `generalized' grazing-incidence-angle X-ray diffraction (G-GIXD) method which enables simultaneous measurements both of in- and out-of-plane diffraction images from surface and interface structures has been developed. While the method uses grazing-incidence-angle X-rays like synchrotron radiation as an incident beam in the same manner as in `traditional' GIXD, two-dimensional (area) detectors like image plates and a spherical-type goniometer are used as the data-collection system. In this way, diffraction images both in the Seemann–Bohlin (out-of-plane) and GIXD geometry (in-plane) can be measured simultaneously without scanning the detectors. The method can be applied not only to the analysis of the in-plane crystal structure of epitaxically grown thin films, but also to more general research topics like the structural analysis of polycrystalline mixed phases of thin surface and interface layers.

scholarly journals Multiple scattering in grazing-incidence X-ray diffraction: impact on lattice-constant determination in thin films

2016 ◽  
Vol 23 (3) ◽  
pp. 729-734 ◽  
Author(s):  
Roland Resel ◽  
Markus Bainschab ◽  
Alexander Pichler ◽  
Theo Dingemans ◽  
Clemens Simbrunner ◽  
...  
Keyword(s):  
Thin Films ◽  
Critical Angle ◽  
Grazing Incidence ◽  
X Rays ◽  
Organic Thin Film ◽  
X Ray Diffraction ◽  
Reliable Determination ◽  
X Ray ◽  
Out Of Plane

Dynamical scattering effects are observed in grazing-incidence X-ray diffraction experiments using an organic thin film of 2,2′:6′,2′′-ternaphthalene grown on oxidized silicon as substrate. Here, a splitting of all Bragg peaks in the out-of-plane direction (z-direction) has been observed, the magnitude of which depends both on the incidence angle of the primary beam and the out-of-plane angle of the scattered beam. The incident angle was varied between 0.09° and 0.25° for synchrotron radiation of 10.5 keV. This study reveals comparable intensities of the split peaks with a maximum for incidence angles close to the critical angle of total external reflection of the substrate. This observation is rationalized by two different scattering pathways resulting in diffraction peaks at different positions at the detector. In order to minimize the splitting, the data suggest either using incident angles well below the critical angle of total reflection or angles well above, which sufficiently attenuates the contributions from the second scattering path. This study highlights that the refraction of X-rays in (organic) thin films has to be corrected accordingly to allow for the determination of peak positions with sufficient accuracy. Based thereon, a reliable determination of the lattice constants becomes feasible, which is required for crystallographic structure solutions from thin films.

Effect of ion bombardment during the low-mobility growth of metallic superlattices

1988 ◽  
Vol 3 (5) ◽  
pp. 856-861 ◽  
Author(s):  
B. Window ◽  
F. Sharples
Keyword(s):  
Crystalline Phase ◽  
Lattice Spacing ◽  
Bragg Peak ◽  
Ion Bombardment ◽  
Growth Direction ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Average Lattice ◽  
Profile Change

The structure of sputtered Mo/Fe superlattices of periodicities 9 to 30 Å grown at a substrate temperature of 300 K at various pressures and levels of low-energy ion bombardment have been studied using x-ray diffraction. The samples show the growth of an amorphous phase below 17 Å periodicity and a crystalline phase above 21 Å, with mixed phases in between. Limited ion bombardment reduces the coherency in the growth direction in the crystalline phase, while heavy bombardment sufficient to promote significant mixing acts to improve the coherency, but not to the level observed in films with no bombardment. The relative intensities of the average lattice spacing reflection and its most intense satellite give the composition profile change due to the ion mixing. Some ion bombardment of the iron layer markedly improves the reflectance for x-rays at both low and high angles near the Bragg peak due to the average lattice spacing.

Texture of NiGe(Sn) on Ge(100) and its evolution with Sn content

2021 ◽  
Vol 54 (5) ◽  
pp. 1306-1316
Author(s):  
Andrea Quintero ◽  
Patrice Gergaud ◽  
Tra Nguyen-Thanh ◽  
Jean-Michel Hartmann ◽  
Vincent Reboud ◽  
...  
Keyword(s):  
The Other ◽  
X Ray Diffraction ◽  
Rich Phase ◽  
X Ray ◽  
Pole Figures ◽  
Out Of Plane ◽  
Diffraction Peaks ◽  
The Impact ◽  
Plane Diffraction

The texture of the Ni monostanogermanide phase on a Ge(100) substrate was evaluated during a solid-state reaction, with a focus on the impact of Sn addition. Complementary X-ray diffraction analyses involving in situ X-ray diffraction, in-plane reciprocal space maps (RSMs) and pole figures were used to that end. A sequential growth of the phases for the Ni/Ge(Sn) system was found. An Ni-rich phase formed first, followed by the NiGe(Sn) phase. The NiGe and NiGe(Sn) layers were polycrystalline with different out-of-plane orientations. The number of out-of-plane diffraction peaks decreased with the Sn content, while the preferred orientation changed. In-plane RSM analyses confirmed these results. Sn addition modified the out-of-plane and in-plane orientations. Pole figure analysis revealed that numerous epitaxial texture components were present for the Ni/Ge system, while Sn addition reduced the number of epitaxial texture components. On the other hand, segregated Sn crystallized with an epitaxial alignment with the Ge substrate underneath.

X-ray diffraction properties of curved crystal diffractors

1992 ◽  
Vol 50 (2) ◽  
pp. 1734-1735
Author(s):  
W. Z. Chang ◽  
D. B. Wittry
Keyword(s):  
Diffraction Theory ◽  
X Rays ◽  
Diffraction Image ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Bent Crystal ◽  
Diffraction Geometry ◽  
Crystal Parameter ◽  
Quantitative Procedure

Since Du Mond and Kirkpatrick first discussed the principle of a bent crystal spectrograph in 1930, curved single crystals have been widely utilized as spectrometric monochromators as well as diffractors for focusing x rays diverging from a point. Curved crystal diffraction theory predicts that the diffraction parameters - the rocking curve width w, and the peak reflection coefficient r of curved crystals will certainly deviate from those of their flat form. Due to a lack of curved crystal parameter data in current literature and the need for optimizing the choice of diffraction geometry and crystal materials for various applications, we have continued the investigation of our technique presented at the last conference. In the present abstract, we describe a more rigorous and quantitative procedure for measuring the parameters of curved crystals.The diffraction image of a singly bent crystal under study can be obtained by using the Johann geometry with an x-ray point source.

Investigation of the phase shift in X-ray forward diffraction using an X-ray interferometer

1998 ◽  
Vol 5 (3) ◽  
pp. 967-968 ◽  
Author(s):  
Keiichi Hirano ◽  
Atsushi Momose
Keyword(s):  
Phase Shift ◽  
Silicon Crystal ◽  
Dynamical Theory ◽  
Perfect Crystal ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bragg Geometry

The phase shift of forward-diffracted X-rays by a perfect crystal is discussed on the basis of the dynamical theory of X-ray diffraction. By means of a triple Laue-case X-ray interferometer, the phase shift of forward-diffracted X-rays by a silicon crystal in the Bragg geometry was investigated.

scholarly journals X-ray crystal structure of a malonate-semialdehyde dehydrogenase fromPseudomonassp. strain AAC

2017 ◽  
Vol 73 (1) ◽  
pp. 24-28 ◽  
Author(s):  
Matthew Wilding ◽  
Colin Scott ◽  
Thomas S. Peat ◽  
Janet Newman
Keyword(s):  
Crystal Structure ◽  
Search Model ◽  
Molecular Replacement ◽  
X Rays ◽  
X Ray Diffraction ◽  
Acetyl Coa ◽  
Space Group ◽  
X Ray ◽  
Semialdehyde Dehydrogenase

The NAD-dependent malonate-semialdehyde dehydrogenase KES23460 fromPseudomonassp. strain AAC makes up half of a bicistronic operon responsible for β-alanine catabolism to produce acetyl-CoA. The KES23460 protein has been heterologously expressed, purified and used to generate crystals suitable for X-ray diffraction studies. The crystals belonged to space groupP212121and diffracted X-rays to beyond 3 Å resolution using the microfocus beamline of the Australian Synchrotron. The structure was solved using molecular replacement, with a monomer from PDB entry 4zz7 as the search model.

scholarly journals Electronic Excitations and Radiation Damage in Macromolecular Crystallography

Crystals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 273 ◽  
Author(s):  
José Brandão-Neto ◽  
Leonardo Bernasconi
Keyword(s):  
Chemical Information ◽  
X Rays ◽  
Electronic Excitations ◽  
Macromolecular Crystallography ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Structures ◽  
Successful Approach ◽  
Structural Research

Macromolecular crystallography at cryogenic temperatures has so far provided the majority of the experimental evidence that underpins the determination of the atomic structures of proteins and other biomolecular assemblies by means of single crystal X-ray diffraction experiments. One of the core limitations of the current methods is that crystal samples degrade as they are subject to X-rays, and two broad groups of effects are observed: global and specific damage. While the currently successful approach is to operate outside the range where global damage is observed, specific damage is not well understood and may lead to poor interpretation of the chemistry and biology of the system under study. In this work, we present a phenomenological model in which specific damage is understood as the result of a single process, the steady excitation of crystal electrons caused by X-ray absorption, which acts as a trigger for the bulk effects that manifest themselves in the form of global damage and obscure the interpretation of chemical information from XFEL and synchrotron structural research.

Applications of High-Resolution Powder X-Ray Diffraction

2007 ◽  
Vol 130 ◽  
pp. 7-14 ◽  
Author(s):  
Andrew N. Fitch
Keyword(s):  
High Resolution ◽  
Synchrotron Radiation ◽  
Powder Diffraction ◽  
X Rays ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Structural Characterisation ◽  
Pdf Analysis

The highly-collimated, intense X-rays produced by a synchrotron radiation source can be harnessed to build high-resolution powder diffraction instruments with a wide variety of applications. The general advantages of using synchrotron radiation for powder diffraction are discussed and illustrated with reference to the structural characterisation of crystalline materials, atomic PDF analysis, in-situ and high-throughput studies where the structure is evolving between successive scans, and the measurement of residual strain in engineering components.

Structural Properties Of Co/Re Superlattices

1991 ◽  
Vol 238 ◽  
Author(s):  
Y. Huai ◽  
R. W. Cochrane ◽  
Y. Shi ◽  
H. E. Fischer ◽  
M. Sutton
Keyword(s):  
Structural Disorder ◽  
Multilayer Films ◽  
Film Plane ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bilayer Films ◽  
Out Of Plane ◽  
Reflectivity Data ◽  
Sharp Interfaces ◽  
Good Agreement

ABSTRACTThe structures of equal-thickness Co/Re multilayer films and several Co/Re bilayer films have been investigated by X-ray diffraction at low and high angles. Analysis of low-angle reflectivity data from bilayer films indicates that interfacial intermixing is limited to three monolayers and that the two interfacial configurations are different. The high-angle X-ray diffraction data show that multilayer films have coherent interfaces and a highly textured structure with hep [002] orientations normal to the film plane for periods 21 Å ≤ Λ ≤220 Å. Detailed structures have been determined by fitting the X-ray spectra to calculated ones using a trapezoidal model. The results indicate that samples with 42 Å≤ Λ ≤220 Å have relatively sharp interfaces, in good agreement with the bilayer results. In addition, an out-of-plane expansion of the Co (002) layer is observed in samples with large Λ and results from structural disorder leading to a reduced atomic density. For Λ <21 Å the interfaces arise from the rougher surfaces of the deposited layers.

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