A two-circle powder diffractometer for synchrotron radiation with a closed loop encoder feedback system

Cernik, Robert J.; Murray, Paul; Pattison, Philip; Fitch, Andrew N.

doi:10.1107/s0021889890003648

Cited by 100 publications

(46 citation statements)

References 9 publications

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“…Based on the parallel beam optics of Parrish et al (1986), the Daresbury synchrotron radiation source station 2.3 diffractometer used in our experiment was originally constructed for ambient high-resolution powder diffraction studies (Cernik et al 1990;Collins et al 1992). Located 15 m tangentially from a 1.2 T dipole magnet in the 2 GeV electron storage ring (Munro 1997) it receives X-rays in the range 0.7-2.5Å.…”

Section: Methodsmentioning

confidence: 99%

Laboratory investigation of crystallisation in annealed amorphous MgSiO$\mathsf{_{3}}$

Thompson

Tang

2001

A&A

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Abstract. In situ high resolution synchrotron X-ray powder diffraction measurements are used to probe the structural changes in a sample of amorphous MgSiO3 during annealing. Temperatures cover the astrophysically significant range 1000 K to 1173 K and prior to annealing the sample showed typical amorphous structure. Following ∼2 hours annealing at 1000 K an initial crystallite had formed that was coexistent with a modified amorphous component. Increases in temperature coupled with long annealing times produced no further change to the amorphous component and only very minor changes in the appearance of the crystalline phase. This we identify as a structural stall in the crystallisation process and is likely to be the origin of the spectral stall reported for similar silicate materials. Finally at 1173 K, following a cumulative annealing time of ∼79 hours, the amorphous background began to collapse coinciding with the development of further crystalline features. The stall in structural development arises because the crystallisation process is in part regulated by the amorphous phase during annealing. At low-end temperatures it is likely that the annealing process itself strengthens the amorphous phase allowing it to survive up to relatively high temperatures. This finding suggests that some lower temperature information may be preserved in certain cosmic dust grains that were initially annealed at lower temperatures.

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Section: Methodsmentioning

confidence: 99%

Laboratory investigation of crystallisation in annealed amorphous MgSiO$\mathsf{_{3}}$

Thompson

Tang

2001

A&A

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“…a simple receiving slit instead of the analyzer crystal) with the sample in a 0.5 mm capillary. Data for cloverite were collected on beamline 8.3 at the Synchrotron Radiation Source (SRS) in Daresbury, UK, with a¯at-plate sample and long predetector Soller slits (Cernik et al, 1990). Details of the various data collection parameters are given in Table 1.…”

Section: Data Collection and Intensity Extractionmentioning

confidence: 99%

Zeolite structure determination from powder diffraction data: applications of theFOCUSmethod

McCusker¹,

Baerlocher²

1999

J Appl Cryst

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The FOCUS approach to zeolite structure determination from powder diffraction data has been applied to data from four different zeolitic materials. The solutions of the structures of two aluminophosphate molecular sieves, YUL-89 (AWO topology) and , are used to demonstrate routine applications of the procedure. The high-silica zeolite ZSM-5 (MFI topology), which has 12 Si atoms (38 framework atoms) in the asymmetric unit, and the gallophosphate cloverite (-CLO topology), the framework of which is not fully fourfold connected, provide examples of extreme cases, which challenge the limits of the FOCUS algorithm. Taken together, the four examples give an overview of the practical aspects of the FOCUS method and illustrate its potential and its limitations.

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“…Other special qualities are described elsewhere [2]. The SRS is a high-resolution powder diffraction instrument [3,4]. Further developments allow the performance of a variety of experiments by users from a diverse scientific community [5].…”

Section: Introductionmentioning

confidence: 99%

Synchrotron X-ray diffraction study of the phase transformations in titanium alloys

Malinov

Sha

Guo

et al. 2002

Materials Characterization

151

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High-resolution synchrotron X-ray diffraction was used to study the phase transformations in titanium alloys. Three titanium alloys were investigated: Ti -6Al -4V, Ti -6Al -2Sn -4Zr -2Mo -0.08Si and b21s. Both room and high temperature measurements were performed. The room temperature experiments were performed to study the structure of the alloys after different heat treatments, namely as received (AR), furnace cooling (FC), water quenching (WQ) and water quenching followed by ageing. The a, a 0 , a 00 and b phases were observed in different combinations depending on the heat treatment conditions and the alloy studied. A multicomponent hexagonal close packed (hcp) a phase, with different c and the same a lattice parameters, was detected in Ti -6Al -4Vafter FC. High temperature synchrotron X-ray diffraction was used for 'in situ' study of the transformations on the sample surface at elevated temperatures. The results were used to trace the kinetics of surface oxidation and the concurrent phase transformations taking place under different conditions. The influence of the temperature and oxygen content on the lattice parameters of the a phase was derived and new data obtained on the coefficients of thermal expansion in the different directions of the hcp a phase, for Ti -6Al -4V and Ti -6Al -2Sn -4Zr -2Mo -0.08Si. D

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A two-circle powder diffractometer for synchrotron radiation with a closed loop encoder feedback system

Cited by 100 publications

References 9 publications

Laboratory investigation of crystallisation in annealed amorphous MgSiO$\mathsf{_{3}}$

Laboratory investigation of crystallisation in annealed amorphous MgSiO$\mathsf{_{3}}$

Zeolite structure determination from powder diffraction data: applications of theFOCUSmethod

Synchrotron X-ray diffraction study of the phase transformations in titanium alloys

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