New five-circle κ diffractometer for reference-beam diffraction studies

2003 ◽  
Vol 36 (1) ◽  
pp. 29-33 ◽  
Author(s):  
Daniel Pringle ◽  
Qun Shen

A compact five-circle κ-geometry diffractometer has been designed and implemented at CHESS for automated reference-beam X-ray diffraction (RBD) experiments. The details of the diffractometer design are presented, along with its geometry calculations, and its alignment and control algorithm. An outline of the overall RBD experimental procedure has been developed based on this κ diffractometer. Measured RBD interference profiles from a lysozyme crystal demonstrate that efficient triplet-phase data collection is possible using this new device in a modified crystallography oscillation setup.

2021 ◽  
Vol 54 (1) ◽  
pp. 371-375
Author(s):  
Paul Monceyron Røren ◽  
Kristoffer W. B. Hunvik ◽  
Vegard Josvanger ◽  
Ole Tore Buseth ◽  
Jon Otto Fossum

A sample cell for powder X-ray diffraction studies with in situ applied pressure and control of temperature is demonstrated. The cell is based on a previously reported design and consists of a glass or quartz capillary glued into a Swagelok weld gland; this configuration can hold up to 100 bar (1 bar = 100 kPa). The cell is placed in contact with a copper plate for control of temperature between −30 and 200°C. This is achieved by Peltier elements, heat cartridges and a refrigerated circulating bath. This work mainly focuses on the temperature control system. Commissioning tests were performed in a custom-made small/wide-angle X-ray diffractometer at the Norwegian University of Science and Technology. The system is easily portable to synchrotron facilities.


2004 ◽  
Vol 443-444 ◽  
pp. 31-34
Author(s):  
Giovanni Berti ◽  
Rob Delhez ◽  
S. Norval ◽  
B. Peplinski ◽  
E. Tolle ◽  
...  

This paper outlines the standardisation process for the XRPD method that is currently being considered by a Working Group (WG10) of Technical Committee 138 "Non-destructive Testing" of the European Committee for Standardisation CEN. Several Standard Documents are on the verge of being released. These documents concern the general principles of (X-ray) diffraction, its terminology, and the basic procedures applied. Another document concerns the instruments used and it offers procedures to characterise and control the performance of an X-ray diffractometer properly. It is intended to issue Standard Documents on specific methods, e.g. determination of residual stresses. In fact work is in progress on this subject. The Standard Documents can be used by industry, government organisations, and research centres with activities related to safety, health and the environment, as well as for educational purposes.


2000 ◽  
Vol 55 (3-4) ◽  
pp. 381-389 ◽  
Author(s):  
J. Nomssi Nzali ◽  
W. Hoyer

Liquid copper, bismuth, and eleven bismuth-copper alloys were investigated at temperatures above the liquidus with X-ray diffraction. The experimental procedure was adjusted to reduce the effects of evaporation. The Faber-Ziman total structure factors S(Q) feature a splitting of the first maximum and negative values for Q around 1 Å -1 in a large concentration range. The results are compared to previous neutron diffraction results by Zaiss and Steeb, to square-well potential model calculations by Gopala Rao and Satpathy and to a simple segregation model. The segregation model reproduces the features qualitatively. Partial structure factors are assessed by fitting both neutron and X-ray scattering results with reverse Monte-Carlo simulation


1999 ◽  
Vol 32 (4) ◽  
pp. 736-743 ◽  
Author(s):  
D. Machajdík ◽  
A. Pevala ◽  
A. Rosová ◽  
K. Fröhlich ◽  
J. Šouc ◽  
...  

CeO2thin films deposited on sapphire monocrystal substrates were used for an experimental study of the nature of extremely narrow overlapped maxima on X-ray diffraction ω scans. Full width at half-maximum (FWHM) values of such maxima typically reached the resolution function of the diffractometer. A comparative study of the influence of various diffractometer set-ups on the spectral characteristics of the X-ray beam in relation to the above-mentioned phenomenon was carried out. A surrounding (λmin− λmax) or (2θmin− 2θmax) of the strong substrate reflection was obtained, where a substrate contribution to an ω scan measured on thin-film reflection can be expected. Two possible origins of the narrow maxima are discussed: (a) a contribution of a part of the X-ray beam having λ ≠ λKαthat diffracts on a set of substrate crystallographic planes parallel to the thin-film crystallographic planes used for the ω-scan measurement; and (b) the presence in part of the thin film of a perfect monocrystal-like quality with practically no mosaicity. The principles of this approach and experimental procedure are reported, and on this basis it is possible to distinguish between the two possible origins of the narrow overlapped maxima. It is shown that under appropriate conditions, an extremely high quality CeO2thin film can be grown. The FWHM value of its ω scan can reach the value of diffractometer instrumental broadening obtained for a perfect monocrystal.


2013 ◽  
Vol 275-277 ◽  
pp. 2300-2303
Author(s):  
Gen Zong Song ◽  
Duo Zhang

In this dissertation, Bi-2212 superconducting tapes was prepared by sol-gel method, in addition we mainly studied heat treatment conditions and sintering material drying conditions of the NiO/Ni substrate, and gived a optimization to the process. The heat treatment process of the NiO/Ni substrate had been researched.Based on previous experience, we explored the temperature of heat treatment and improved the process.Afterheattreatment,the samples was analyzed by metallographic microscope and X-ray diffraction,and we analysed these data. It’s concluded that the dense uniform oxide film can be sintered in 800°C with a 3 hours’ heat treatment.We further explored the conditions of the Bi-2212 superconducting materials.During the preparation. We mainly studied the drying temperature and sintering temperature ,because they would affect the gel phase transition and control components. It has a very important effect on high-quality superconducting strip preparation. Experiments results showed that drying the sample at 510 °C in temperature is best. all the samples was analyzed by X-ray diffraction. We summed up the data derived from experiments , it showed that sintering the sample at 850°C,we can obtain the mixed phase of Bi-2201 and Bi-2212.


2006 ◽  
Vol 309-311 ◽  
pp. 519-522 ◽  
Author(s):  
E.S. Thian ◽  
Jie Huang ◽  
Serena Best ◽  
Zoe H. Barber ◽  
William Bonfield

Nanostructured hydroxyapatite (nHA) thin coatings of thickness 0.5 µm have been successfully produced using a radio-frequency magnetron sputtering technique, through careful selection and control of the processing conditions. nHA coatings were immersed in simulated body fluid (SBF) to determine the rate of nucleation and growth of an apatite layer on their surface. A dense, newlyformed apatite layer with similar characteristics to that of the biological bone apatite, was observed after 7 days of immersion in SBF. X-ray diffraction and infrared analyses confirmed this layer to be calcium-deficient nanocrystalline carbonate HA. All these results demonstrated that the novel nHA coatings were highly bioactive, and the time-frame required to form a dense apatite layer was reduced significantly as compared to the micrometer-sized, sintered HA pellets (from 28 days to 7 days).


2010 ◽  
Vol 43 (4) ◽  
pp. 926-928 ◽  
Author(s):  
X. R. Huang

LauePtis a robust and extremely easy-to-use Windows application for accurately simulating, indexing and analyzing white-beam X-ray diffraction Laue patterns of any crystals under arbitrary diffraction geometry. This program has a user-friendly graphic interface and can be conveniently used by nonspecialists with little X-ray diffraction or crystallography knowledge. Its wide range of applications include (1) determination of single-crystal orientation with the Laue method, (2) white-beam topography, (3) white-beam microdiffraction, (4) X-ray studies of twinning, domains and heterostructures, (5) verification or determination of crystal structures from white-beam diffraction, and (6) teaching of X-ray crystallography.


2015 ◽  
Vol 2 (7) ◽  
pp. 150006 ◽  
Author(s):  
Takashi Kosone ◽  
Akihiro Hori ◽  
Eiji Nishibori ◽  
Yoshiki Kubota ◽  
Akio Mishima ◽  
...  

The ability to design and control properties of nano-sized space in porous coordination polymers (PCPs) would provide us with an ideal stage for fascinating physical and chemical phenomena. We found an interconversion of nuclear-spin isomers for hydrogen molecule H 2 adsorbed in a Hofmann-type PCP, {Fe(pz)[Pd(CN) 4 ]} (pz=pyrazine), by the temperature dependence of Raman spectra. The ortho (o)–para (p) conversion process of H 2 is forbidden for an isolated molecule. The charge density study using synchrotron radiation X-ray diffraction reveals the electric field generated in coordination nano-space. The present results corroborate similar findings observed on different systems and confirm that o–p conversion can occur on non-magnetic solids and that electric field can induce the catalytic hydrogen o–p conversion.


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