Journal of Applied Crystallography

 

J. Appl. Cryst. (2003). 36, 1107-1115  [ doi:10.1107/S0021889803011580 ]

Diffraction peak profiles from spherical crystallites with lognormal size distribution

T. Ida, S. Shimazaki, H. Hibino and H. Toraya

Synopsis: An efficient method to calculate the theoretical diffraction peak profiles from spherical crystallites with lognormal size distribution is presented. The intrinsic diffraction peak profiles of SiC powder, obtained by a whole-pattern deconvolution method, have shown `super-Lorentzian' shape, which can be well reproduced by the theoretical profile for the logarithmic standard deviation of the size distribution = 0.93.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1116-1122  [ doi:10.1107/S0021889803012421 ]

Automatic inference of protein quaternary structure from crystals

H. Ponstingl, T. Kabir and J. M. Thornton

Synopsis: An algorithmic procedure is proposed to infer the multimeric state of a water-soluble protein from contacts between its polypeptide chains observed in the crystal.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1123-1127  [ doi:10.1107/S0021889803012597 ]

A full-pattern fitting algorithm for energy-dispersive X-ray diffraction

Y.-H. Dong, J. Liu, Y.-C. Li and X.-D. Li

Synopsis: A new algorithm for full-pattern fitting for energy-dispersive X-ray diffraction is described, considering the errors in measuring the energy and diffraction angle, and also the fluorescence peaks. A lognormal function is introduced to represent the strong background.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1128-1134  [ doi:10.1107/S0021889803012615 ]

Monte Carlo simulation of models for biological systems: thermodynamic properties and small-angle scattering from collections of interacting binary mixtures of spheres

B. Sjöberg

Synopsis: As models for highly concentrated biological and other colloidal systems, computer simulations using Monte Carlo methods are used to study two bidisperse systems of spheres, one system consisting of mixtures of hard spheres and the other consisting of mixtures of hard spheres and spheres having an additional repulsive potential.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1135-1143  [ doi:10.1107/S0021889803012755 ]

Residual stresses in tool steel due to hard-turning

N. Ordás, M. L. Penalva, J. Fernández and C. García-Rosales

Synopsis: The residual stress depth distribution of hard-turned tool steel has been measured by X-ray diffraction using an integral method, which allows the determination of the stress gradient tensors in the tangential, radial and depth directions.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1144-1147  [ doi:10.1107/S0021889803012998 ]

Thick-mode resonance of a PZT/Si wafer stack investigated by X-ray diffraction in Bragg geometry

P. E. N. de Souza, C. Cusatis, C. K. Saul, A. R. D. Rodrigues and P. C. de Camargo

Synopsis: X-ray diffraction in Bragg geometry was used to investigate the effects of longitudinal standing waves on an Si(111) wafer, constructing a PZT/Si(111) stack with a resonant frequency of 2.34 MHz. In addition to the ultrasonic vibration, a thermal effect is evident, which has been mostly ignored or avoided in previous reports.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1148-1158  [ doi:10.1107/S0021889803013542 ]

Determination of nanoparticle structure type, size and strain distribution from X-ray data for monatomic f.c.c.-derived non-crystallographic nanoclusters

A. Cervellino, C. Giannini and A. Guagliardi

Synopsis: Whole-profile-fitting least-squares techniques are successfully applied to simulated and experimental diffraction patterns of monatomic f.c.c.-derived non-crystallographic nanoclusters, with the aim of extracting information about structure-type concentration, size and strain distribution.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1159-1168  [ doi:10.1107/S0021889803013748 ]

In situ determination of stresses from time-of-flight neutron transmission spectra

A. Steuwer, J. R. Santisteban, P. J. Withers, L. Edwards and M. E. Fitzpatrick

Synopsis: Results of in situ tensile stress measurements on austenitic and ferritic steel specimens using the pulsed neutron transmission method are reported. The results show that the transmission method can be used to determine residual and applied stresses, as well as to resolve the effects of elastic anisotropy.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1169-1176  [ doi:10.1107/S002188980301375X ]

Accuracy in Rietveld quantitative phase analysis of Portland cements

A. G. De la Torre and M. A. G. Aranda

Synopsis: The accuracy in Rietveld quantitative mineralogical analyses of artificial standard Portland cement mixtures using laboratory X-ray powder diffraction has been assessed employing high-energy synchrotron X-ray powder diffraction.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1177-1181  [ doi:10.1107/S0021889803013736 ]

General-case data interpretation of spin-echo small-angle neutron scattering

J. Zhao

Synopsis: Following previous works on data interpretation in the case of a one-dimensionally encoded spin-echo small-angle neutron scattering instrument when the scattering data are collected along a single direction, further studies for the more general case of data collection in two dimensions are presented.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1182-1189  [ doi:10.1107/S0021889803013955 ]

Strategies for solving neighboring-element problems: a case study using resonant X-ray diffraction and pulsed neutron diffraction to examine Sr₈Ga₁₆Ge₃₀

Y. Zhang, A. P. Wilkinson, G. S. Nolas, P. L. Lee and J. P. Hodges

Synopsis: Resonant scattering can produce considerable contrast in samples presenting a neighboring-element problem, enabling the precise determination of site occupancies. However, the accuracy of the site occupancies depends upon the data collection and analysis strategy that is adopted.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1190-1196  [ doi:10.1107/S0021889803014262 ]

Estimation of chord length distributions from small-angle scattering using indirect Fourier transformation

S. Hansen

Synopsis: A method for estimation of chord length distributions from small-angle scattering data using indirect Fourier transformation is suggested. Examples are given using simulated data.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1197-1203  [ doi:10.1107/S002188980301433X ]

Twinning in La_0.95Sr_0.05Ga_0.9Mg_0.1O_2.92 crystal studied by white-beam (Laue) X-ray microdiffraction

D. I. Savytskii, D. M. Trots, L. O. Vasylechko, N. Tamura and M. Berkowski

Synopsis: The twinning of La_0.95Sr_0.05Ga_0.9Mg_0.1O_2.92 perovskite-type crystals has been studied using the technique of white-beam X-ray microdiffraction. The dominant twin system is formed by the intersection of domain walls (12) and (10) in the crystal.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1204-1213  [ doi:10.1107/S0021889803014468 ]

Scan profiles for neutron spectrometers. I. Gaussian-profile elements by acceptance-diagram methods

L. D. Cussen

Synopsis: Scan profiles for neutron spectrometers using Gaussian-profile beam elements are derived using acceptance diagrams and agree with accepted results.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1214-1224  [ doi:10.1107/S0021889803014456 ]

Scan profiles for neutron spectrometers. II. Rectangular-profile elements by acceptance-diagram methods

L. D. Cussen

Synopsis: An analytic comparison of the scan profiles and peak intensity for conventional and reflecting Soller neutron collimators is reported.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1225-1229  [ doi:10.1107/S002188980301447X ]

Scan profiles for neutron spectrometers. III. Rectangular-profile elements by numerical methods

L. D. Cussen and A. R. Wildes

Synopsis: Numerical tests using McSTAS show that reflecting neutron collimators, if used correctly, more than double peak intensity on powder diffractometers with no resolution cost. The tests confirm the validity of the acceptance-diagram method and the results should apply to similar devices for X-ray or electron scattering.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1230-1235  [ doi:10.1107/S0021889803014766 ]

Habit modification of nearly perfect single crystals of potassium dihydrogen phosphate (KDP) by trivalent manganese ions studied using synchrotron radiation X-ray multiple diffraction in Renninger scanning mode

X. Lai, K. J. Roberts, L. H. Avanci, L. P. Cardoso and J. M. Sasaki

Synopsis: The analysis of Renninger scans of Mn³⁺-doped KDP crystals is consistent with the presence of the impurity species chemically bound within the KDP crystal structure, as confirmed through the suppression of the huge observed peak asymmetry, characteristic of perfect crystals. In addition, an extra Renninger-scan peak measured for the doped material is indicative of the impurity atoms occupying interstitial crystallographic sites in the lattice, a result consistent with X-ray standing-wave measurements.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1236-1239  [ doi:10.1107/S0021889803014912 ]

In situ X-ray diffraction studies of aluminium-induced crystallization of hydrogenated amorphous silicon

R. Kishore, C. Hotz, H. A. Naseem and W. D. Brown

Synopsis: The crystallization behaviour of aluminium-capped -Si:H was monitored using the 111 silicon peak as a function of annealing temperature between 273 and 523 K. The results show that aluminium-induced crystallization of -Si:H initiates at a temperature between 413 and 423 K, with crystallization rate increasing with increasing temperature and saturating for an anneal of 30 min at a temperature of 523 K.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1240-1255  [ doi:10.1107/S0021889803014924 ]

Texture and microstructure imaging in six dimensions with high-energy synchrotron radiation

H. J. Bunge, L. Wcislak, H. Klein, U. Garbe and J. R. Schneider

Synopsis: The complete description of the texture of a polycrystalline material requires three orientational and three space coordinates. Using high-energy synchrotron radiation together with a moving-area-detector technique various two-dimensional sections and projections of this six-dimensional space can be continuously imaged, which, in grain-resolved textures, provides the complete orientation stereology of the polycrystalline material.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1256-1261  [ doi:10.1107/S002188980301481X ]

Investigation of distorted subsurface layers of thick perfect crystals

A. O. Aboyan and H. R. Drmeyan

Synopsis: It is shown that in the presence of distorted subsurface layers, the occurrence of reflection structures (fine lines) depends on the divergence and monochromaticity of the incident beam, as well as on the absorption and character of X-ray scattering on distorted layers and in the main bulk (perfect part) of the crystal.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1262-1265  [ doi:10.1107/S0021889803014948 ]

Intensity and resolution effects in converging multichannel collimators for SANS by Monte Carlo simulation

A. N. Falcão, F. M. A. Margaça and F. G. Carvalho

Synopsis: A simulation study of the performance of a converging multichannel collimator for small-angle neutron scattering reveals the effect of the incident neutron beam divergence on the transmission of individual channels.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1266-1269  [ doi:10.1107/S002188980301495X ]

A contribution to the practical implementation of a variable-geometry converging multichannel collimator for SANS

A. N. Falcão, F. M. A. Margaça and F. G. Carvalho

Synopsis: The practical implementation of a converging multichannel collimator with discontinuous walls for use in small-angle neutron scattering instruments is reported.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1270-1271  [ doi:10.1107/S0021889803014778 ]

Note on Bravais-Miller indices

D. Schwarzenbach

Synopsis: Readers are reminded of the meaning and applicability of four-membered zone indices.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1272-1273  [ doi:10.1107/S0021889803018879 ]

MgCl₂.2.5C₂H₅OH-NaCl mixed crystals

X. Jiang and Z. Fan

Synopsis: The formation of two kinds of mixed crystals of MgCl₂ and NaCl, by ball milling magnesium chloride-ethanol adducts together with sodium chloride, is described.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1274-1276  [ doi:10.1107/S0021889803014031 ]

SAPI: a direct-methods program for finding heavy-atom sites with SAD or SIR data

Q. Hao, Y. X. Gu, J. X. Yao, C. D. Zheng and H. F. Fan

Synopsis: SAPI is a CCP4-format program that applies a direct-methods procedure to find heavy-atom sites using single-wavelength anomalous dispersion or single-isomorphous replacement data.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1277-1282  [ doi:10.1107/S0021889803012779 ]

PRIMUS: a Windows PC-based system for small-angle scattering data analysis

P. V. Konarev, V. V. Volkov, A. V. Sokolova, M. H. J. Koch and D. I. Svergun

Synopsis: A Wintel-based menu-driven program suite PRIMUS allows the user to perform major tasks of one-dimensional small-angle scattering data processing and analysis.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1283-1284  [ doi:10.1107/S0021889803015267 ]

OLEX: new software for visualization and analysis of extended crystal structures

O. V. Dolomanov, A. J. Blake, N. R. Champness and M. Schröder

Synopsis: The program OLEX provides tools for the visualization and topological analysis of extended network structures, as well as allowing more conventional representations.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1285-1287  [ doi:10.1107/S0021889803016789 ]

CIF applications. XII. Inspecting Rietveld fits from pdCIF: pdCIFplot

B. H. Toby

Synopsis: The pdCIFplot program for inspecting Rietveld refinement fits reported in pdCIF files is presented.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1288-1289  [ doi:10.1107/S0021889803016790 ]

CIF applications. XIII. CIFEDIT, a program for viewing and editing CIFs

B. H. Toby

Synopsis: The program CIFEDIT, which is used for the review and editing of CIFs, is described.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1290-1294  [ doi:10.1107/S0021889803016819 ]

CIF applications. XIV. Reporting of Rietveld results using pdCIF: GSAS2CIF

B. H. Toby, R. B. Von Dreele and A. C. Larson

Synopsis: The program GSAS2CIF for the creation of pdCIFs from GSAS is described.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1295-1296  [ doi:10.1107/S0021889803013724 ]

Microscope detection options for colorless protein crystals grown in lipidic cubic phases

P. Nollert

Synopsis: Cross polarization microscopy or Hoffman modulation contrast microscopy allows the detection of colorless microcrystals grown in a matrix of lipidic cubic phase.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1297-1298  [ doi:10.1107/S0021889803014006 ]

A quick and gentle method for mounting crystals in capillaries

R. Basavappa, E. T. Petri and B. S. Tolbert

Synopsis: A quick and gentle method for mounting of crystals in capillaries is presented.

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1299  [ doi:10.1107/S0021889803014377 ]

Quasicrystals. The state of the art

Online 8 September 2003

 

J. Appl. Cryst. (2003). 36, 1299  [ doi:10.1107/S0021889803013013 ]

High-resolution electron microscopy

Online 8 September 2003