Rapid collection of X-ray powder data for pattern analysis by a cylindrical position-sensitive detector

Abstract

An apparatus has been developed which permits rapid collection of X‐ray powder diffraction data for structure refinement by pattern analysis. The apparatus is built on a cylindrical position‐sensitive detector with an angular aperture of 120° and resolution of 0.05° in 2θ. The detector uses a metal blade as anode and works in the self‐quenching streamer mode of gas ionization. A wide‐angle powder pattern can be recorded simultaneously from a stationary specimen, where geometrical broadening of reflection lines is suppressed by limiting the angular width of the incident beam. A test made with standard corundum powder shows that a diffraction pattern with a substantially better resolution is obtainable in one‐eightieth the time compared with a normal θ–2θ diffractometer. The usefulness of the apparatus in high‐temperature work has been demonstrated in profile refinement of structural parameters for the δ phase of bismuth oxide at 1057 K.

Solidification characteristics of metastable and stable

“…Both the stable γ -Bi 12 SiO 20 and the metastable δ-Bi 12 SiO 20 could be directly solidified from the stoichiometric melt of 6Bi 2 O 3 • SiO 2 (namely Bi 12 SiO 20 if the reaction has proceeded to completion) [8]. The nomenclatures for Bi 12 SiO 20 were taken from the polymorphism of Bi 2 O 3 , α-Bi 2 O 3 (monoclinic), β-Bi 2 O 3 (tetragonal), γ -Bi 2 O 3 (BCC) and δ-Bi 2 O 3 (FCC) [7,[9][10][11][12][13][14][15]. However, literature sources on the phase transitions of Bi 12 SiO 20 are relatively few.…”

Crystal structure determination of lithium diborate hydrate, LiB2O3(OH).H2O, from X-ray powder diffraction data collected with a curved position-sensitive detector

“…Structure refinements by the Rietveld method from data collected by means of a curved PSD have also been reported (e.g. Shishiguchi, Minato & Hashizume, 1986;St~.hl & Thomasson, 1992). Although the quality of the uniformity of the response over its angular range required special attention, a reasonable accuracy in the results was obtained.…”

A curved image-plate detector system for high-resolution synchrotron X-ray diffraction

“…Furthermore, the advent of synchrotron X-ray sources has propelled the need to develop X-ray detectors to conduct dynamic studies in real time (Hall & Lewis, 1994). Amongst the various detector systems which have been considered in the past are (i) multi-detector systems (Fitch, 2004;Lee et al, 2008) and (ii) position-sensitive detectors (PSDs), which include linear sensitive proportional counters (Evain et al, 1993;Shishiguchi et al, 1986;Wö lfel, 1983), charge coupled devices (i.e. CCDs) and image-plate (IP) systems (Amemiya, 1995;Norby, 1997;Stå hl, 2000).…”