Recording of X-Ray Diffraction Patterns Using Flash X-Rays in Connection with an Image Intensifier

1971 ◽  
Vol 80 (11) ◽  
pp. 900-901 ◽  
Author(s):  
F. Jamet
Keyword(s):  
Image Intensifier ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns

X-Ray Diffraction

2021 ◽  
pp. 408-480
Author(s):  
Kannan M. Krishnan
Keyword(s):  
Point Group ◽  
Polycrystalline Materials ◽  
X Rays ◽  
X Ray Diffraction ◽  
Symmetry Point Group ◽  
X Ray ◽  
Atomic Scattering ◽  
Scattering Factor ◽  
Diffraction Patterns ◽  
Lattice Planes

X-rays diffraction is fundamental to understanding the structure and crystallography of biological, geological, or technological materials. X-rays scatter predominantly by the electrons in solids, and have an elastic (coherent, Thompson) and an inelastic (incoherent, Compton) component. The atomic scattering factor is largest (= Z) for forward scattering, and decreases with increasing scattering angle and decreasing wavelength. The amplitude of the diffracted wave is the structure factor, F hkl, and its square gives the intensity. In practice, intensities are modified by temperature (Debye-Waller), absorption, Lorentz-polarization, and the multiplicity of the lattice planes involved in diffraction. Diffraction patterns reflect the symmetry (point group) of the crystal; however, they are centrosymmetric (Friedel law) even if the crystal is not. Systematic absences of reflections in diffraction result from glide planes and screw axes. In polycrystalline materials, the diffracted beam is affected by the lattice strain or grain size (Scherrer equation). Diffraction conditions (Bragg Law) for a given lattice spacing can be satisfied by varying θ or λ — for study of single crystals θ is fixed and λ is varied (Laue), or λ is fixed and θ varied to study powders (Debye-Scherrer), polycrystalline materials (diffractometry), and thin films (reflectivity). X-ray diffraction is widely applied.

The Use of 2-D Detector Utilizing Laser-Stimulated Luminescence for X-ray Diffraction Studies on Mechanical Behaviour of Materials

1989 ◽  
Vol 33 ◽  
pp. 389-396 ◽  
Author(s):  
Y. Yoshioka ◽  
T. Shinkai ◽  
S. Ohya
Keyword(s):  
Fracture Analysis ◽  
X Rays ◽  
Large Reduction ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Material Evaluation ◽  
Position Sensitive ◽  
Diffraction Patterns ◽  
Position Sensitive Detectors

The development of linear position-sensitive detectors (PSD) has resulted in a large reduction of data acquisition times in the field of x-ray stress analysis. However, we also require two-dimensional (2-D) diffraction patterns for material evaluation. Especially, the microbeam x-ray diffraction technique gives valuable information on the structure of crystalline materials and this technique has been applied to fracture analysis by x-rays. Many kinds of 2-D PSD have been developed that have insufficient spatial resolution. So x-ray film has still been used as a 2-D detector, but it requires relatively long exposure times and then the process after exposure is very troublesome.

Electrochemical Deposition and Characterization of Cd-Fe-Se Thin Films

2009 ◽  
Vol 68 ◽  
pp. 69-76 ◽  
Author(s):  
S. Thanikaikarasan ◽  
T. Mahalingam ◽  
K. Sundaram ◽  
Tae Kyu Kim ◽  
Yong Deak Kim ◽  
...  
Keyword(s):  
Thin Films ◽  
Hexagonal Structure ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Iron Selenide ◽  
Glass Substrates ◽  
Diffraction Patterns ◽  
Cadmium Iron Selenide ◽  
Deposited Films

Cadmium iron selenide (Cd-Fe-Se) thin films were deposited onto tin oxide (SnO2) coated conducting glass substrates from an aqueous electrolytic bath containing CdSO4, FeSO4 and SeO2 by potentiostatic electrodeposition. The deposition potentials of Cadmium (Cd), Iron (Fe), Selenium (Se) and Cadmium-Iron-Selenide (Cd-Fe-Se) were determined from linear cathodic polarization curves. The deposited films were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive analysis by x-rays (EDX) and optical absorption techniques, respectively. X-ray diffraction patterns shows that the deposited films are found to be hexagonal structure with preferential orientation along (100) plane. The effect of FeSO4 concentration on structural, morphological, compositional and optical properties of the films are studied and discussed in detail.

Flash X-Ray Diffraction Systems

1972 ◽  
Vol 16 ◽  
pp. 229-241 ◽  
Author(s):  
Jonathan A. Dantzig ◽  
Robert E. Green
Keyword(s):  
Fiber Optic ◽  
Single Channel ◽  
Image Intensifier ◽  
Electron Beam Current ◽  
X Ray Diffraction ◽  
Output Window ◽  
Visible Image ◽  
X Ray ◽  
Detection Systems ◽  
Diffraction Patterns

AbstractIn order to develop an optimum system for flash x-ray diffraction, consideration must be given to both optimum x-ray generation and optimum x-ray detection in the correct wavelength regime suitable for diffraction. Historically, most workers have concentrated their efforts in either the generation area or detection area, but not both. As early as 1942, experimental recording of Laue diffraction patterns was reported using a pulsed x-ray generator and exposure times of milliseconds. Recently, successful x-ray diffraction experiments have been reported with exposure times less than 100 nanoseconds.The purpose of the present paper is to trace the development of generation and detection systems for flash x-ray diffraction and to summarize the present state-of-the-art for such systems. A comparative evaluation is presented for flash x-ray diffraction systems using generators which rely on increased electron beam current and those which rely on higher potential difference. Comparison is also made between detection systems incorporating film recording, scintillators fiber-optically coupled to photomultiplier tubes, and image-intensifier systems both lens and fiber-optically coupled to fluorescent screens.A detailed description of the most rapid flash x-ray diffraction system developed to date is given. This system uses a Field Emission Fexitron single channel 300 kilovolt pulsed x-ray generator incorporating an x-ray tube with a beryllium output window. A fluorescent screen converts the x-ray diffraction image into a visible one and this visible image is focused on the first stage photocathode of an image intensifier tube either by direct fiber-optic coupling or by using a coupling lens. The image intensifier tube used is a cascaded three-stage electrostatic focus type with fiber-optic input and output faceplates and inter-stage couplers. Using this system Laue transmission diffraction patterns of single crystals and powder patterns of polycrystalline aggregates have been obtained with exposure times of 30 nanoseconds.

Developments in Analytical Diffraction Using Isotopic X-Ray Sources

1970 ◽  
Vol 14 ◽  
pp. 139-145
Author(s):  
W. S. Toothacker ◽  
L. E. Preuss
Keyword(s):  
Exposure Time ◽  
Specific Activity ◽  
X Rays ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
X Ray ◽  
Oak Ridge ◽  
Position Sensitive ◽  
Diffraction Patterns ◽  
Intense Source

AbstractLobov et al., in Leningrad, and workers at this laboratory have been working on the idea of using x rays from radioactive sources for x ray diffraction analysis. The Russians have been using iron-55 produced by the (n, Y) reaction in their work with a small focusing camera which operates in the back reflection region. We have been using iron-55 produced by the (p,n) reaction in conjunction with a small Debye-Scherrer camera. The preliminary work of this laboratory was reported at this conference two years ago. At that time a 13 mCi iron-55 source was used in a two inch diameter Debye-Scherrer camera to obtain x-ray diffraction patterns of LiF. The exposure times were of the order of 120 hours and the reflection from the 200 plane was about 3 degrees wide. Since that time a new and more intense source has been constructed at Oak Ridge National Laboratories. With the new source it was possible to produce LiF diffraction patterns of the same density and resolution as before in a period of less than ten hours.The above mentioned diffraction patterns were made with the LiF powder placed in a 1.0 mm diameter glass capillary. After reduction of the glass capillary diameter to 0.5 mm and appropriate reduction of the collimator width, we were able to improve the resolution considerably with no accompanying reduction in line density. The LiF patterns obtained in this way required an exposure time of about 20 hours and the width of the reflection from the 200 plane has been reduced to about 1.5 degrees.Hence we are able to report a reduction in exposure time from 116 hours to 20 hours and an increase in resolution by a factor of two over the data reported here two years ago. Thus the concept of using x rays from an isotope for powder diffraction has changed from a laboratory curiosity into a technique with practical possibilities. Both sources mentioned above were produced by the (p, n) reaction. The 135 mCi source had a specific activity of about 400 Ci/gm. Since iron-55 sources have been made with specific activities of about 1000 Ci/gm, a considerable decrease in exposure time could be accomplished by using such a source. The application to this work of a position sensitive proportional counter as developed by Semmler will also be discussed.

scholarly journals Time-resolved X-ray diffraction at NERL

2001 ◽  
Vol 19 (1) ◽  
pp. 125-131 ◽  
Author(s):  
KENICHI KINOSHITA ◽  
HIDEKI HARANO ◽  
KOJI YOSHII ◽  
TAKERU OHKUBO ◽  
ATSUSHI FUKASAWA ◽  
...  
Keyword(s):  
Research Laboratory ◽  
Experimental Results ◽  
X Rays ◽  
Nuclear Engineering ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Engineering Research ◽  
Fs Laser ◽  
Diffraction Patterns

For ultrafast material analyses, we constructed the time-resolved X-ray diffraction system utilizing ultrashort X-rays from laser-produced plasma generated by the 12-TW–50-fs laser at the Nuclear Engineering Research Laboratory. Ultrafast transient changes in laser-irradiated GaAs crystals were observed as X-ray diffraction patterns. Experimental results were compared with numerical analyses.

Identification of Crystalline Materials: Classification and Use of X-Ray Diffraction Patterns

1986 ◽  
Vol 1 (1) ◽  
pp. 2-6 ◽  
Author(s):  
J. D. Hanawalt ◽  
H. W. Rinn
Keyword(s):  
Theoretical Basis ◽  
X Rays ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Chemical Company ◽  
The Past ◽  
Different Types ◽  
Diffraction Patterns ◽  
Or Applications

In the course of the past few years, X-ray and spectroscopic methods of analysis have found an increasing usefulness at the Dow Chemical Company. There are a large number of different types of problems on which information can be obtained by the variations of apparatus and technic which are possible in these two fields. It is not the purpose of this paper, however, to discuss these methods or applications in general, but to describe in some detail a scheme of classifying and using X-ray diffraction patterns which has been found very helpful in one particular application of X-rays — namely, that of identifying unknown substances by means of their Hull powder diffraction patterns.The inherent power of X-ray diffraction as a practical means of chemical analysis was pointed out a good many years ago. Having a different theoretical basis and depending upon an entirely different technic than other methods, it would be expected to supplement the information to be obtained from other methods and, at times, to be applicable where other methods are not suitable. It appears, however, that the use of this method has not increased at a rate commensurate with its unique and valuable features, and that it is used by relatively few academic and industrial laboratories.

Micro X-ray diffraction analysis of thin films using grazing-exit conditions

1998 ◽  
Vol 5 (3) ◽  
pp. 902-904 ◽  
Author(s):  
Takashi Noma ◽  
Atsuo Iida
Keyword(s):  
Sample Surface ◽  
Exit Angle ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Sensitivity ◽  
Refraction Effect ◽  
Glancing Angle ◽  
Diffraction Patterns ◽  
Focused Beam

An X-ray diffraction technique using a hard X-ray microbeam for thin-film analysis has been developed. To optimize the spatial resolution and the surface sensitivity, the X-ray microbeam strikes the sample surface at a large glancing angle while the diffracted X-ray signal is detected with a small (grazing) exit angle. Kirkpatrick–Baez optics developed at the Photon Factory were used, in combination with a multilayer monochromator, for focusing X-rays. The focused beam size was about 10 × 10 µm. X-ray diffraction patterns of Pd, Pt and their layered structure were measured. Using a small exit angle, the signal-to-background ratio was improved due to a shallow escape depth. Under the grazing-exit condition, the refraction effect of diffracted X-rays was observed, indicating the possibility of surface sensitivity.

scholarly journals Picosecond time-resolved X-ray diffraction from laser-shocked semiconductors

2004 ◽  
Vol 22 (3) ◽  
pp. 285-288 ◽  
Author(s):  
KAZUTAKA G. NAKAMURA ◽  
YOICHIRO HIRONAKA ◽  
HIDETAKA KAWANO ◽  
HIROAKI KISHIMURA ◽  
KEN-ICHI KONDO
Keyword(s):  
Shock Wave ◽  
Wave Propagation ◽  
Structural Dynamics ◽  
Lattice Deformation ◽  
X Rays ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Femtosecond Laser Beam ◽  
Diffraction Patterns

Ultrashort pulsed hard X rays are generated by focusing an intense femtosecond laser beam onto metal targets. Kαemissions are obtained from a Cu target. Picosecond time-resolved X-ray diffraction is performed to investigate structural dynamics of laser-shocked semiconductors using the laser plasma X-ray pulses. Lattice deformation associated with shock-wave propagation is directly observed. Evolution of strain profiles inside the crystal is determined without disturbance from the time-resolved X-ray diffraction patterns.

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