Automatic sample changer for the analysis of powder samples on an X-ray single-crystal diffractometer equipped with an area detector

2011 ◽  
Vol 45 (1) ◽  
pp. 135-137
Author(s):  
Alejandro B. Rodriguez-Navarro ◽  
Krzysztof Kudlacz ◽  
Miguel Ortega-Huertas
Keyword(s):  
Single Crystal ◽  
Low Cost ◽  
Single Experiment ◽  
X Ray ◽  
Automatic Sample Changer ◽  
Sample Changer ◽  
Area Detector ◽  
Bruker Smart Apex ◽  
Current Design ◽  
Powder Samples

A low-budget automatic sample changer that allows the rapid analysis of powder or polycrystalline samples using an X-ray single-crystal diffractometer equipped with an area detector is here described. It uses control software that synchronizes the movement of a linear stage with the collection of frames by the diffractometer. Small pieces of thin solid samples are directly attached to a 30 cm ruler, which is used as a disposable magazine, while loose powder samples are loaded into holes on an acetate strip covered on both sides with Kapton tape and attached to the ruler. The use of this type of diffractometer with a sample changer is a simple, low cost and effective solution for studies requiring the analysis of a large number of samples by X-ray powder diffraction. With the current design up to 30 samples can be measured in a single experiment. The current sample changer was designed so that it can be fitted into a Bruker SMART APEX X-ray single-crystal diffractometer. However, it can be easily adapted to diffractometers from other makers.

scholarly journals Single-crystal diffraction data from powder samples via SFX

2014 ◽  
Vol 70 (a1) ◽  
pp. C1449-C1449
Author(s):  
Tao Zhang ◽  
Shifeng Jin ◽  
Yuanxin Gu ◽  
Yao He ◽  
Haifu Fan
Keyword(s):  
Single Crystal ◽  
Diffraction Data ◽  
Three Dimensional ◽  
Monte Carlo Integration ◽  
X Ray Diffraction ◽  
Single Crystal Diffraction ◽  
Single Experiment ◽  
X Ray ◽  
Powder Samples ◽  
Diffraction Patterns

With the serial femtosecond crystallography (SFX) [1] using hard X-ray free-electron laser as light source, it is possible to obtained three-dimensional single-crystal diffraction data from powder samples consisting of submicron crystal grains. This offers two advantages. First, complicated crystal structures far beyond the ability of powder X-ray diffraction analysis now can be solved easily; second, mixtures of two or more crystalline components can be examined in a single experiment. The percentage of each component can be determined accurately and the crystal structure of them can be solved readily. Simulating calculations were performed with a mixture of two different kinds of zeolites. The program suite CrystFEL [2] was used for simulating SFX diffraction patterns, diffraction indexing and Monte-Carlo integration of diffraction intensities. The program suite SHELX [3] was used for structure determination. Satisfactory results have been obtained and will be discussed in detail.

Registering pole figures using an X-ray single-crystal diffractometer equipped with an area detector

2007 ◽  
Vol 40 (3) ◽  
pp. 631-634 ◽  
Author(s):  
Alejandro B. Rodriguez-Navarro
Keyword(s):  
Single Crystal ◽  
Three Dimensional ◽  
Polycrystalline Sample ◽  
Polycrystalline Materials ◽  
X Ray ◽  
Area Detector ◽  
Pole Figures ◽  
Bruker Smart Apex ◽  
Dimensional Distribution ◽  
Textured Materials

The orientation of crystals in a polycrystalline sample is adequately described using pole figures, displaying the three-dimensional distribution of specific crystallographic directions or poles. Registration of pole figures is necessary to characterize the preferred orientation of crystals and its influence on the anisotropy of properties in textured materials. It is also useful to understand the development of highly organized microstructures in polycrystalline materials. Pole figures can be registered efficiently using an area detector, available at most modern single-crystal diffractometers. This paper describes in detail the procedure of data collection and processing of pole figures using a single-crystal diffractometer equipped with an area detector. Specifically, a Bruker SMART APEX diffractometer was used, but this methodology can be readily adapted to other diffractometers.

Powder X-ray diffraction data for Ba4ZnTi11O27 and Ba2ZnTi5O13

1994 ◽  
Vol 9 (1) ◽  
pp. 56-62 ◽  
Author(s):  
C. G. Lindsay ◽  
C. J. Rawn ◽  
R. S. Roth
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Dimensions ◽  
Powder Samples ◽  
Unit Cell Dimensions

Single crystals and powder samples of Ba4ZnTi11O27 and Ba2ZnTi5O13 have been synthesized and studied using single-crystal X-ray precession photographs and X-ray powder diffraction. Unit cell dimensions were calculated from a least-squares refinement with a final maximum Δ2θ of 0.05°. Both phases were found to have monoclinic cells, space group C2/m. The refined lattice parameters for the Ba4ZnTi11O27 compound are a= 19.8687(8) Å, b=11.4674(5) Å, c=9.9184(4) Å, β= 109.223(4)°, and Z=4. The refined lattice parameters for the Ba2ZnTi5O13 compound are a= 15.2822(7) Å, b=3.8977(1) Å, c=9.1398(3) Å, β=98.769(4)°, and Z=2.

Automatic sample changer for Norelco vertical x-ray diffractometer

1970 ◽  
Vol 40 (3) ◽  
pp. 1052-1054
Author(s):  
C. E. Payton ◽  
W. C. Patterson ◽  
G. L. Brown
Keyword(s):  
X Ray ◽  
Automatic Sample Changer ◽  
Sample Changer

scholarly journals Redetermination of the crystal structures of rare-earth trirhodium diboride RERh3B2 (RE = Pr, Nd and Sm) from single-crystal X-ray data

2022 ◽  
Vol 78 (1) ◽  
Author(s):  
Makoto Tokuda ◽  
Kunio Yubuta ◽  
Toetsu Shishido ◽  
Kazumasa Sugiyama
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Crystal Structures ◽  
Site Symmetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Type Layer ◽  
Wyckoff Position ◽  
Powder Samples ◽  
Anisotropic Displacement Parameters

The crystal structures of the rare-earth (RE) trirhodium diborides praseodymium trirhodium diboride, PrRh3B2, neodymium trirhodium diboride, NdRh3B2, and samarium trirhodium diboride, SmRh3B2, were refined on the basis of single-crystal X-ray diffraction data. The crystal chemistry of RERh3B2 (RE: Pr, Nd, and Sm) compounds has previously been analyzed mainly on the basis of powder samples [Ku et al. (1980). Solid State Commun. 35, 91–96], and no structural investigation by single-crystal X-ray diffraction has been reported so far. The crystal structures of the three hexagonal RERh3B2 compounds are isotypic with that of CeRh3B2; RE, Rh and B sites are situated on special positions with site symmetry 6/mmm (Wyckoff position 1a), mmm (3g) and \overline{6}m2 (2c), respectively. In comparison with the previous powder X-ray study of hexagonal RERh3B2, the present redetermination against single-crystal X-ray data has allowed for the modeling of all atoms with anisotropic displacement parameters (ADPs). The ADPs of the Rh atom in each of the structures result in an elongated displacement ellipsoid in the direction of the stacking of the Rh kagomé-type layer. The features of obtained ADPs of atoms are discussed in relation to RERh3B2-type and analogous structures.

A Modular Automatic X-Ray Ahalysis System

1971 ◽  
Vol 15 ◽  
pp. 135-147 ◽  
Author(s):  
M. Slaughter ◽  
Davis Carpenter
Keyword(s):  
Operating System ◽  
Single Crystal ◽  
Electron Microprobe ◽  
Computer Hardware ◽  
Linear Regression Method ◽  
Sample Number ◽  
X Ray ◽  
Sample Changer ◽  
Powder Diffractometer ◽  
Computer Controlled

A modular x-ray and electron beam system has been constructed to accomplish most standard types of x-ray analysis automatically. The system includes a vertical powder diffractometer, a vacuum spectrograph, a four-axis single-crystal diffractometer and an electron microprobe with four spectrometers. The system is controlled by a single computer with auxilliary drum storage. The powder diffractometer has automatic goniometer drive, automatic sample changing with computer cataloging of samples and automatic variable divergence slit. The x-ray spectrograph is a standard unit with added 100 KV capability, automated goniometer drive, eight or 32 position sample changer, six-analyzing-crystal changer, collimator changer, and detector changer. All functions including sample number cataloguing are computer controlled. The four-axis single crystal diffractometer has all functions computer controlled and includes peak search option. The electron microprobe/scanning electron microscope has all spectrometers, x, y, z stage motions and sample changer controlled by computer. X-Ray channels, beam current and sample current are automatically read-out. Control of probe functions and correction of mechanical errors in stage operation, are aided by a digital beam scanner with a light pen. Counting channels and computer interfacing are modular, and channel components are interchangable by the operator. Computer hardware may be expanded and the software is modular. Any combination of instruments up to eight may be operated.The computer operates all instruments simultaneously in a time-sharing mode. Programs consist of operating system programs, individual instrument programs and data processing programs. The operating system drives all x-ray hardware, fetches programs and data from the drum, allocates data storage, queues final results for printing and performs other necessary executive functions. For qualitative analysis, spectra for each instrument are collected automatically in several modes and are stored on the drum. A variety of methods are used to remove background, strip unwanted peaks and find peak position and intensity. A.S.T.M. diffraction, spectrographic and special files are maintained on the drum. Quantitative analysis is executed automatically using a version of "MAGIC" on the electron microprobe and a multiple linear regression method for the spectrograph and diffractometer.

X-ray characterization of GaN single crystal layers grown by the ammonothermal technique on HVPE GaN seeds and by the sublimation technique on sapphire seeds

2004 ◽  
Vol 831 ◽  
Author(s):  
Balaji Raghothamachar ◽  
Michael Dudley ◽  
Buguo Wang ◽  
Michael Callahan ◽  
David Bliss ◽  
...  
Keyword(s):  
Single Crystal ◽  
Low Cost ◽  
Laser Diodes ◽  
Growth Conditions ◽  
Defect Structures ◽  
X Ray Diffraction ◽  
Lithium Amide ◽  
X Ray ◽  
Sublimation Growth

ABSTRACTSingle crystal GaN substrates are a more reliable, efficient and low cost alternative to sapphire and SiC substrates that are currently being used for developing nitride based devices such as LEDs, high power FETs and laser diodes. GaN growth by two techniques are investigated here. In ammonothermal growth (analogous to hydrothermal growth which is commonly used for quartz), using potassium and lithium amide as mineralizers and GaN powders and vapor grown polycrystals as nutrients, thick GaN single crystal layers have been grown on both faces of (0001) HVPE GaN seeds in nickel based autoclaves. In GaN sublimation growth, Ga is transported under a temperature gradient in an ammonia atmosphere from a GaN powder source to the sapphire substrate which has a 3–6 micron GaN epilayer deposited on it. Synchrotron white beam x-ray topography (SWBXT) was initially used to image the defect structures in the layers. High resolution x-ray diffraction experiments were also carried out and reciprocal space maps were recorded from the grown GaN layers. Characterization results will be discussed with respect to the growth conditions.

scholarly journals Key metrics for single-crystal two-dimensional X-ray area-detector systems

2012 ◽  
Vol 68 (a1) ◽  
pp. s150-s150
Author(s):  
Z. Gál ◽  
A. Griffin ◽  
F. White ◽  
O. Presly ◽  
D. Kucharczyk ◽  
...  
Keyword(s):  
Single Crystal ◽  
Two Dimensional ◽  
X Ray ◽  
Area Detector

The Linear Coefficient of Thermal Expansion of Silicon at Room Temperature

1991 ◽  
Vol 6 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Liu Fengchao ◽  
Zheng Bin
Keyword(s):  
Thermal Expansion ◽  
Single Crystal ◽  
Room Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Silicon Single Crystal ◽  
Linear Coefficient ◽  
X Ray ◽  
Crystal State ◽  
Powder Diffractometer ◽  
Powder Samples

AbstractThe linear coefficient of thermal expansion for three silicon single-crystal samples, taken from the head, middle, and tail of the same boule, and their powder samples have been measured at room temperature by using an X-ray powder diffractometer. All samples yield the same expansion value α=2.45 (± 0.04) × 10−6 °C at 25 °C. The results of this experiment show that the linear coefficient of thermal expansion of silicon at room temperature is not dependent on its single-crystal state or its powder state.

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