Position-sensitive detector system OBI for High Resolution X-Ray Powder Diffraction using on-site readable image plates

Author(s):  
M Knapp ◽  
V Joco ◽  
C Baehtz ◽  
H.H Brecht ◽  
A Berghaeuser ◽  
...  
1988 ◽  
Vol 21 (6) ◽  
pp. 905-910 ◽  
Author(s):  
M. S. Lehmann ◽  
A. N. Christensen ◽  
M. Nielsen ◽  
R. Feidenhans'l ◽  
D. E. Cox

1990 ◽  
Vol 205 ◽  
Author(s):  
Axel NØrlund Christensen

AbstractTime resolved X-ray powder diffraction was used to follow the crystallization processes in the systems MgO-MgCl2-H2O and MgO-H2O. A Stoe X-ray powder diffractometer with a position sensitive detector was used. The crystalline reaction products are [Mg2(OH)3(H2O)2]C1.H2O and Mg(OH)2 dependent upon the MgC12 concentrations in the heterogeneous systems. Mg(OH)2 was the product in a 1.50 M MgCl2 solution and [Mg2(OH)3(H2O)3]Cl.H2O was formed in 3.00 and 5.17 M MgCl2 solutions at 20°C.


1984 ◽  
Vol 55 (9) ◽  
pp. 1455-1460 ◽  
Author(s):  
B. A. Fraass ◽  
P. R. Granfors ◽  
R. O. Hilleke ◽  
R. O. Simmons

1980 ◽  
Vol 24 ◽  
pp. 123-138 ◽  
Author(s):  
Herbert E. Göbel

AbstractBy collecting the diffracted X-rays in a focussing powder diffractometer with a linear position-sensitive detector (PSD), the data accumulation time can be widely reduced. Due to the focussing properties of the geometrical arrangement good resolution can be simultaneously achieved over a few degrees of the diffraction angle 2 Theta. The full pattern is collected by scanning the PSD along the entire 2 Theta arc. Scanning speeds of several hundred degrees per minute are possible and still yield well plotted diagrams.This work demonstrates the performance of the system in different tasks of X-ray powder diffraction such as identification of unknown materials, quantitative analysis, determination of lattice constants and microcrystalline properties. The results, evaluated by parts of the program system DIFFRAC 11, show that the accuracy and resolution of the continuously scanning PSD technique match these tasks without difficulty and reach the precision limits of powder diffractometry itself. It is demonstrated that the data collection velocity, which matches well the data evaluation times, is not the only advantage compared to conventional diffractometets.


2020 ◽  
Vol 86 (6) ◽  
pp. 29-35
Author(s):  
V. P. Sirotinkin ◽  
O. V. Baranov ◽  
A. Yu. Fedotov ◽  
S. M. Barinov

The results of studying the phase composition of advanced calcium phosphates Ca10(PO4)6(OH)2, β-Ca3(PO4)2, α-Ca3(PO4)2, CaHPO4 · 2H2O, Ca8(HPO4)2(PO4)4 · 5H2O using an x-ray diffractometer with a curved position-sensitive detector are presented. Optimal experimental conditions (angular positions of the x-ray tube and detector, size of the slits, exposure time) were determined with allowance for possible formation of the impurity phases during synthesis. The construction features of diffractometers with a position-sensitive detector affecting the profile characteristics of x-ray diffraction peaks are considered. The composition for calibration of the diffractometer (a mixture of sodium acetate and yttrium oxide) was determined. Theoretical x-ray diffraction patterns for corresponding calcium phosphates are constructed on the basis of the literature data. These x-ray diffraction patterns were used to determine the phase composition of the advanced calcium phosphates. The features of advanced calcium phosphates, which should be taken into account during the phase analysis, are indicated. The powder of high-temperature form of tricalcium phosphate strongly adsorbs water from the environment. A strong texture is observed on the x-ray diffraction spectra of dicalcium phosphate dihydrate. A rather specific x-ray diffraction pattern of octacalcium phosphate pentahydrate revealed the only one strong peak at small angles. In all cases, significant deviations are observed for the recorded angular positions and relative intensity of the diffraction peaks. The results of the study of experimentally obtained mixtures of calcium phosphate are presented. It is shown that the graphic comparison of experimental x-ray diffraction spectra and pre-recorded spectra of the reference calcium phosphates and possible impurity phases is the most effective method. In this case, there is no need for calibration. When using this method, the total time for analysis of one sample is no more than 10 min.


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