Journal of Applied Crystallography

 

J. Appl. Cryst. (2000). 33, 1  [ doi:10.1107/S0021889800000200 ]

A new format and overall appearance for Journal of Applied Crystallography

G. Kostorz

Synopsis: Editorial.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 2-9  [ doi:10.1107/S0021889899010328 ]

Study of the influence of oxygen on structural perfection of silicon single crystals by high-resolution X-ray diffraction and infrared absorption measurements

K. Lal, R. R. Ramanan and G. Bhagavannarayana

Synopsis: The crystalline perfection of silicon crystals grown by the float zone (FZ) method is generally slightly lower than that of crystals grown by the Czochralski (Cz) technique, which have higher oxygen content. High-resolution X-ray diffraction studies and infrared-absorption measurements have shown that, if the level of oxygen in FZ silicon crystals is increased by annealing, from 1.3 × 10¹⁷ to 13 × 10¹⁷  atoms  cm (typical values for Cz crystals), the degree of perfection of FZ crystals increases remarkably, approaching that of the Cz crystals.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 10-25  [ doi:10.1107/S0021889899010894 ]

New developments of computer-aided crystallographic analysis in transmission electron microscopy

S. Zaefferer

Synopsis: A computer program for on-line crystal orientation measurements based on spot and Kikuchi electron diffraction patterns in TEM is presented. The program facilitates the complete characterization of lattice defects, such as dislocations and grain boundaries.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 26-34  [ doi:10.1107/S0021889899010973 ]

Contribution to residual-stress evaluation in high-stress-gradient zones by X-ray diffraction

V. Hennion, J. M. Sprauel and H. Michaud

Synopsis: A new strategy to analyse both the mechanical and the metallurgical state in high-stress gradient zones is proposed. The measurement and treatment methods have been adapted and a complete modelling of the X-ray source has been developed to account for the local intensity distribution.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 35-48  [ doi:10.1107/S0021889899011929 ]

Correction of specimen absorption in X-ray diffuse scattering experiments with area-detector systems

S. Scheidegger, M. A. Estermann and W. Steurer

Synopsis: Methods for the correction of specimen absorption, dedicated to two-dimensional area-detector systems and broad diffuse scattering phenomena, are implemented and tested. Synchrotron radiation diffraction experiments and numerical calculations are used to study the influence of experimental parameters on the accuracy of the absorption correction which is applied pixel-wise.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 49-51  [ doi:10.1107/S0021889899012029 ]

Three-beam interference measurements with a six-circle diffractometer

G. Thorkildsen, H. B. Larsen, R. H. Mathiesen and F. Mo

Synopsis: The feasibility of a specific six-circle diffractometer for measuring three-beam interference profiles is outlined.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 52-63  [ doi:10.1107/S0021889899012364 ]

Integration procedure for the quantitative analysis of dispersive anomalous diffraction

V. Favre-Nicolin, S. Bos, J. E. Lorenzo, P. Bordet, W. Shepard and J.-L. Hodeau

Synopsis: Dispersive diffraction allows the simultaneous measurement of diffracted intensities over an energy range. This method has been developed and a procedure for the quantitative integration of dispersive diffraction images for continuous (DAFS-like) and discrete (MAD-like) experiments is described.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 64-70  [ doi:10.1107/S0021889899012625 ]

Study of thermal behaviour of 30Li₂O·70TeO₂ glass by X-ray dynamic observation

T. Taniguchi, S. Inoue, T. Mitsuhashi and A. Nukui

Synopsis: The dynamical structural changes of 30Li₂O·70TeO₂ glass were mainly studied by in situ high-temperature X-ray diffraction. The phase transitions of lithium tellurite at high temperature were clarified, including reversible changes between -Li₂Te₂O₅ and -Li₂Te₂O₅.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 71-81  [ doi:10.1107/S0021889899012571 ]

X-ray diffraction study of polycrystalline p-chloronitrobenzene

C. A. Meriles, J. F. Schneider, Y. P. Mascarenhas and A. H. Brunetti

Synopsis: The X-ray diffraction pattern of powdered 1-Cl-4-NO₂-benzene was measured at several temperatures in order to characterize the structure of two different phases.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 82-86  [ doi:10.1107/S0021889899012807 ]

Accuracy of molecular structures determined from high-resolution powder diffraction. The example of m-fluorobenzoic acid

P. Pattison, K. D. Knudsen and A. N. Fitch

Synopsis: The accuracy with which it is possible to determine atomic coordinates of light atoms at arbitrary positions using X-ray powder data alone is demonstrated. The results are compared with those of a single-crystal study on the same compound.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 87-94  [ doi:10.1107/S002188989901290X ]

Nanopowder diffraction analysis beyond the Bragg law applied to palladium

Z. Kaszkur

Synopsis: Tools for nanopowder diffraction analysis, based on simulation, are proposed.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 95-102  [ doi:10.1107/S0021889899013060 ]

Crystal structure refinement of -Si₃N₄ using synchrotron radiation powder diffraction data: unbiased refinement strategy

H. Toraya

Synopsis: The crystal structure of -silicon nitride (Si₃N₄) was refined by the Rietveld method using synchrotron radiation powder diffraction data. A refinement procedure using a new weight function for least-squares fitting was studied, and guidelines for an unbiased refinement procedure were derived.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 103-107  [ doi:10.1107/S002188989901345X ]

Diffraction-line shift caused by residual stress in polycrystal for all Laue groups in classical approximations

N. C. Popa

Synopsis: Expressions are derived within the Voigt and Reuss approximations, describing the anisotropic diffraction-line shift caused by the elastic strain in isotropic polycrystals. These expressions, appropriate for the Rietveld programs, are different for different Laue groups.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 108-111  [ doi:10.1107/S0021889899013461 ]

A tool for X-ray diffraction analysis of thin layers on substrates: substrate peak removal method

J.-D. Kamminga, R. Delhez, Th. H. de Keijser and E. J. Mittemeijer

Synopsis: A method is proposed that removes from a diffraction pattern, in which overlapping peaks of a thin layer and a substrate are present, the substrate peaks, using a separate measurement of an uncovered substrate. The method is shown to yield good results for a TiN layer deposited on a tool-steel substrate.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 112-117  [ doi:10.1107/S0021889899013643 ]

Sample geometry effects on incoherent small-angle scattering of light water

F. Carsughi, R. P. May, R. Plenteda and J. Saroun

Synopsis: It is shown that the scattering intensities of light water collected with different ratios of sample-to-beam dimension present large differences as a function of sample thickness. In particular, ratios smaller and larger than unity are considered and the results are discussed and compared with Monte Carlo simulations.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 118-125  [ doi:10.1107/S002188989901417X ]

Double monochromator with three pairs of crystals for a SANS machine: Monte Carlo simulation studies

V. K. Aswal, J. V. Joshi, P. S. Goyal and A. V. Pimpale

Synopsis: Monte Carlo calculations for the resolution and intensity of a double-crystal monochromator system for a small-angle neutron scattering machine are presented. The relative merits of this monochromator as compared to our available monochromators are discussed.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 126-129  [ doi:10.1107/S0021889899014168 ]

Origin of the optical activity of silver thiogallate

J. Etxebarria, C. L. Folcia and J. Ortega

Synopsis: The birefringence and optical activity of AgGaS₂ have been determined using a high-accuracy universal polarimeter. The data are compared with those of previous works and the connection between the optical properties and crystal structure is discussed.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 130-136  [ doi:10.1107/S0021889899014272 ]

On the instrumental resolution in X-ray reflectivity experiments

D. Sentenac, A. N. Shalaginov, A. Fera and W. H. de Jeu

Synopsis: A general form of the instrumental resolution function is given for X-ray reflectivity experiments.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 137-146  [ doi:10.1107/S0021889899014454 ]

Instrumental line shapes in neutron powder diffraction with focusing monochromators

A. D. Stoica, M. Popovici and W. B. Yelon

Synopsis: The assumption of Gaussian line shapes and Caglioti profile functions leads to a good quality of fit in whole-pattern refinements, not only with conventional instruments, but also with focusing instruments. The quality of the fit improved on approximating instrumental line shapes with double cumulative functions.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 147-155  [ doi:10.1107/S0021889899012947 ]

Position-sensitive analysis in curved-crystal three-axis neutron spectrometry (quasielastic scattering case)

A. D. Stoica, M. Popovici, W. B. Yelon and R. Berliner

Synopsis: The use of bent perfect crystals in three-axis neutron spectroscopy with position-sensitive detection is analysed. High intensities at high resolutions are achievable through focusing in scattering combined with `thickness focusing' from multilamella analysers.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 156-167  [ doi:10.1107/S0021889899012790 ]

Accurate structure-factor measurements using high-energy synchrotron radiation: a test on cuprite, Cu₂O

T. Lippmann and J. R. Schneider

Synopsis: Structure factors were measured for cuprite, Cu₂O, using 100  keV synchrotron radiation, with an accuracy that allowed full multipole refinements.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 168-171  [ doi:10.1107/S0021889899012406 ]

A cryocooling technique for protein crystals grown by dialysis from volatile solvents

E. J. Fernandez, A. Joachimiak and E. Lolis

Synopsis: This paper describes a cryocooling method, based on the use of dialysis adaptors for 24-well crystallization plates, that permits the transfer of crystals with greater ease and lower risk of mechanical damage.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 172-173  [ doi:10.1107/S0021889899012388 ]

Preparation of silver behenate coatings to provide low- to mid-angle diffraction calibration

T. N. Blanton, C. L. Barnes and M. Lelental

Synopsis: Specimens of silver behenate that exhibit a high degree of preferred orientation have been prepared. Multiple (0 0 l) diffraction peaks, (0 0 1) to (0 0 48), are easily observed using a conventional laboratory X-ray diffraction instrument.

Online 1 February 2000

    

J. Appl. Cryst. (2000). 33, 174-175  [ doi:10.1107/S0021889899012327 ]

CRUNCH: a phase refinement program for high-resolution macromolecular structures

D. A. Langs, R. H. Blessing and G. D. Smith

Synopsis: A phase refinement program for high-resolution macromolecular structures is described that may allow the mean phase error of an initial structure solution to be reduced before inspecting a map to see how well it may fit a structural model.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 176-183  [ doi:10.1107/S0021889899012339 ]

TOP: a new method for protein structure comparisons and similarity searches

G. Lu

Synopsis: In order to facilitate the three-dimensional structure comparison of proteins, software for making comparisons and searching for similarities to protein structures in databases has been developed.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 184-189  [ doi:10.1107/S002188989901434X ]

MarqX: a new program for whole-powder-pattern fitting

Y. H. Dong and P. Scardi

Synopsis: MarqX can be used for an unconstrained profile fitting (pattern decomposition) or constrained modelling of the whole powder pattern (Pawley method), for single- as well as multiple-phase samples.

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 190  [ doi:10.1107/S0021889800000303 ]

Crystallographic Instrumentation

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 190  [ doi:10.1107/S0021889899015903 ]

New Cryostream Cooler

Online 1 February 2000

 

J. Appl. Cryst. (2000). 33, 191-196  [ doi:10.1107/S0021889899014521 ]

Notes for Authors

Online 1 February 2000