Journal of Applied Crystallography

 

J. Appl. Cryst. (2009). 42, 369-375  [ doi:10.1107/S0021889809009145 ]

High-resolution three-dimensional reciprocal-space mapping of InAs nanowires

S. O. Mariager, S. L. Lauridsen, A. Dohn, N. Bovet, C. B. Sørensen, C. M. Schlepütz, P. R. Willmott and R. Feidenhans'l

Synopsis: Grazing-incidence X-ray diffraction is combined with a two-dimensional pixel detector to obtain three-dimensional reciprocal-space maps of InAs nanowires grown by molecular beam epitaxy.

Online 3 April 2009

 

J. Appl. Cryst. (2009). 42, 376-384  [ doi:10.1107/S0021889809008784 ]

PDB_REDO: automated re-refinement of X-ray structure models in the PDB

R. P. Joosten, J. Salzemann, V. Bloch, H. Stockinger, A.-C. Berglund, C. Blanchet, E. Bongcam-Rudloff, C. Combet, A. L. Da Costa, G. Deleage, M. Diarena, R. Fabbretti, G. Fettahi, V. Flegel, A. Gisel, V. Kasam, T. Kervinen, E. Korpelainen, K. Mattila, M. Pagni, M. Reichstadt, V. Breton, I. J. Tickle and G. Vriend

Synopsis: The majority of previously deposited X-ray structures can be improved by applying current refinement methods.

Online 3 April 2009

 

J. Appl. Cryst. (2009). 42, 385-391  [ doi:10.1107/S0021889809008450 ]

Implementation and use of robust refinement in powder diffraction in the presence of impurities

K. H. Stone, S. H. Lapidus and P. W. Stephens

Synopsis: A modification to the usual least-squares analysis is implemented, to refine structural parameters from powder diffraction data containing an unmodeled impurity. The method is characterized using known materials, and two new structures are refined using the method.

Online 28 April 2009

 

J. Appl. Cryst. (2009). 42, 392-400  [ doi:10.1107/S0021889809011492 ]

High-energy X-ray diffuse scattering

I. B. Ramsteiner, A. Schöps, H. Reichert, H. Dosch, V. Honkimäki, Z. Zhong and J. B. Hastings

Synopsis: The use of high-energy X-rays as a tool to map the diffuse scattering in reciprocal space is discussed. Particular emphasis is put on the influence of multiple scattering effects on the measured intensity distributions.

Online 28 April 2009

 

J. Appl. Cryst. (2009). 42, 401-410  [ doi:10.1107/S0021889809006888 ]

A rigorous comparison of X-ray diffraction thickness measurement techniques using silicon-on-insulator thin films

A. J. Ying, C. E. Murray and I. C. Noyan

Synopsis: For ideal specimens, thin-film thickness values obtained from high-resolution X-ray diffraction techniques have accuracies of about 1 nm and precisions one or two orders of magnitude smaller. The use of multiple X-ray techniques is required to ensure reliable thickness determination.

Online 28 April 2009

 

J. Appl. Cryst. (2009). 42, 411-415  [ doi:10.1107/S002188980901036X ]

Morphology and etch figures of a Yb:YAl₃(BO₃)₄ crystal

S. R. Zhao, J. Meng, R. Wang, Z. H. Qiu and L. J. Wang

Synopsis: The etch figures of three forms ({110}, {20} and {101}) of the self-frequency-doubling crystal Yb:YAl₃(BO₃)₄ were observed and the point group 32 was displayed. Etch figures of faces or sections with the same indices in Yb:YAl₃(BO₃)₄ and quartz are very similar, although their crystal structures are very different.

Online 28 April 2009

 

J. Appl. Cryst. (2009). 42, 416-428  [ doi:10.1107/S0021889809011807 ]

Elastic constants of fibre-textured thin films determined by X-ray diffraction

K. J. Martinschitz, R. Daniel, C. Mitterer and J. Keckes

Synopsis: Supposing the Hill grain-interaction model, it is demonstrated that X-ray elastic constants can be used to determine mechanical elastic constants of cubic fibre-textured thin films. The new approach is demonstrated by the experimental characterization of out-of-plane moduli of fibre-textured Cu and CrN thin films.

Online 2 May 2009

 

J. Appl. Cryst. (2009). 42, 429-432  [ doi:10.1107/S0021889809015349 ]

Preferred orientation of ettringite in concrete fractures

H.-R. Wenk, P. J. M. Monteiro, M. Kunz, K. Chen, N. Tamura, L. Lutterotti and J. Del Arroz

Synopsis: Hard synchrotron X-ray microdiffraction is used to quantify the orientation distribution of ettringite crystals [Ca₆Al₂(OH)₁₂(SO₄)₃·26H₂O], which cause cracking and loss of strength in concrete structures.

Online 15 May 2009

 

J. Appl. Cryst. (2009). 42, 433-441  [ doi:10.1107/S0021889809015702 ]

Enantiomorph identification and stacking faults in -(BEDT-TTF)₂Cu(NCS)₂ by convergent-beam electron diffraction

S. Fujio, K. Tanaka, H. Inui, R. Ueji, N. Sumida, H. Yamochi and G. Saito

Synopsis: The enantiomorphs of an ambient-pressure superconductor -(BEDT-TTF)₂Cu(NCS)₂ [BEDT-TTF is bis(ethylenedithio)tetrathiafulvalene] have been successfully identified using the method of convergent-beam electron diffraction. This indicates that a micrometre-sized small crystallite is enough to identify its enantiomorphs even in an organic crystal. Stacking faults in -(BEDT-TTF)₂Cu(NCS)₂ have also been found, the existence of which has not been noted from conventional X-ray diffraction methods.

Online 15 May 2009

 

J. Appl. Cryst. (2009). 42, 442-447  [ doi:10.1107/S0021889809012412 ]

Coordination number in ideal spherical nanocrystals

K. Pirkkalainen and R. Serimaa

Synopsis: The decrease of average atomic coordination number with size in nanocrystals is evaluated using calculations based on ideal spherical crystals.

Online 15 May 2009

 

J. Appl. Cryst. (2009). 42, 448-456  [ doi:10.1107/S0021889809011947 ]

Size distribution and surface characteristics of silicon nanoparticles

D. T. Britton, E. A. Odo, G. G. Gonfa, E. O. Jonah and M. Härting

Synopsis: The size distribution and morphology of silicon nanoparticles have been studied using small-angle X-ray scattering and transmission electron microscopy. Milled particles exhibit surface fractal characteristics and a high size dispersion, whereas particles produced by silane pyrolysis are smooth with a monodisperse distribution.

Online 15 May 2009

 

J. Appl. Cryst. (2009). 42, 457-460  [ doi:10.1107/S0021889809010036 ]

A prototype environmental gas cell for in situ small-molecule X-ray diffraction

J. E. Warren, R. G. Pritchard, D. Abram, H. M. Davies, T. L. Savarese, R. J. Cash, P. R. Raithby, R. Morris, R. H. Jones and S. J. Teat

Synopsis: The development of a prototype environmental gas cell, capable of allowing a single crystal to be exposed to different gas mixtures and/or a vacuum whilst in situ on the single-crystal diffractometer, is reported along with an initial case study.

Online 28 April 2009

 

J. Appl. Cryst. (2009). 42, 461-468  [ doi:10.1107/S0021889809007456 ]

High-pressure small-angle neutron scattering studies of glucose isomerase conformation in solution

E. Banachowicz, M. Kozak, A. Patkowski, G. Meier and J. Kohlbrecher

Synopsis: Small-angle neutron scattering (SANS) studies of glucose/xylose isomerase indicate that the structure of this protein in solution is very stable and very similar to that in the crystal, in a broad pressure range up to 150 MPa. This enzyme can be used as a secondary standard for SANS measurements.

Online 3 April 2009

 

J. Appl. Cryst. (2009). 42, 469-479  [ doi:10.1107/S0021889809008802 ]

Ultra-small-angle X-ray scattering at the Advanced Photon Source

J. Ilavsky, P. R. Jemian, A. J. Allen, F. Zhang, L. E. Levine and G. G. Long

Synopsis: The design and operation of a versatile ultra-small-angle X-ray scattering instrument at the Advanced Photon Source at Argonne National Laboratory are presented.

Online 3 April 2009

 

J. Appl. Cryst. (2009). 42, 480-484  [ doi:10.1107/S0021889809008310 ]

On the tetragonality of the room-temperature ferroelectric phase of barium titanate, BaTiO₃

D. S. Keeble and P. A. Thomas

Synopsis: The recent interpretation in the literature of the diffraction pattern of top-seeded BaTiO₃ as a hybrid structure of monoclinic and tetragonal phases is dismissed in favour of a twinning model, which has been derived from single-crystal CCD diffraction data and confirmed by simulations. BaTiO₃ at room temperature is proved conclusively to be a single phase of tetragonal symmetry.

Online 3 April 2009

 

J. Appl. Cryst. (2009). 42, 485-489  [ doi:10.1107/S0021889809008966 ]

High-performance compact-multi-crystal analyzer for X-ray diffractometer scans

H. Toraya

Synopsis: A new high-performance diffracted-beam analyzer consisting of multiple pieces of a perfect crystal in the form of a simple and compact device is proposed. The X-ray intensity diffracted from the analyzer can be increased by, for example, one order of magnitude compared with that obtained with an ordinary single-crystal analyzer.

Online 3 April 2009

 

J. Appl. Cryst. (2009). 42, 490-495  [ doi:10.1107/S0021889809010085 ]

Lattice parameter determination using a curved position-sensitive detector in reflection geometry and application to Sm_x/2Nd_x/2Ce_1-xO_2- ceramics

A. Pramanick, S. Omar, J. C. Nino and J. L. Jones

Synopsis: An approach to correct for the effect of sample displacement from the Bragg plane on peak position is described for reflection-mode Debye-Scherrer geometry and applied to determine the relationship between composition and lattice parameter in Sm_x/2Nd_x/2Ce_1-xO_2- ceramics.

Online 3 April 2009

 

J. Appl. Cryst. (2009). 42, 496-501  [ doi:10.1107/S0021889809010747 ]

Anisotropic phonon density of states: the application of Rietveld and Mössbauer texture analysis in aligned powders

A. I. Rykov, M. Seto, Y. Ueda and K. Nomura

Synopsis: Measuring the anisotropic properties of materials, such as phonon densities of states, is possible on an anisotropic polycrystal with a well known orientation distribution function (ODF). With this purpose, the ODF is characterized by Rietveld and Mössbauer texture analysis.

Online 28 April 2009

 

J. Appl. Cryst. (2009). 42, 502-512  [ doi:10.1107/S0021889809008681 ]

Energy-dispersive diffraction studies of inert anodes

N. V. Y. Scarlett, I. C. Madsen, J. S. O. Evans, A. A. Coelho, K. McGregor, M. Rowles, M. R. Lanyon and A. J. Urban

Synopsis: Energy-dispersive diffraction data from the Synchrotron Radiation Source at Daresbury Laboratories have been analysed using crystal-structure-based Rietveld refinement. A standardless quantification method has been developed to analyse directly in energy space rather than in d space. Standard mixtures have been quantified to verify the method which has then been applied to a tomographic study of an electrochemical cell.

Online 2 May 2009

 

J. Appl. Cryst. (2009). 42, 513-518  [ doi:10.1107/S0021889809013727 ]

Determination of the degree of preferred orientation within the March-Dollase approach

E. Zolotoyabko

Synopsis: An analytic expression has been derived which connects the degree of preferred orientation in a polycrystalline material to the March parameter. The latter defines the spread of angular distribution of crystallite inclinations in the March-Dollase approach.

Online 15 May 2009

 

J. Appl. Cryst. (2009). 42, 519-524  [ doi:10.1107/S0021889809013107 ]

Determination of surface crystallography of faceted nanoparticles using transmission electron microscopy imaging and diffraction modes

S. Li, Y. Zhang, C. Esling, J. Muller, J.-S. Lecomte, G. W. Qin, X. Zhao and L. Zuo

Synopsis: A general method to determine the surface crystallography and therefore the shape of faceted nanoparticles by transmission electron microscopy is proposed.

Online 15 May 2009

 

J. Appl. Cryst. (2009). 42, 525-530  [ doi:10.1107/S0021889809011315 ]

Facilitating protein crystal cryoprotection in thick-walled plastic capillaries by high-pressure cryocooling

Y.-F. Chen, M. W. Tate and S. M. Gruner

Synopsis: The minimal concentrations of three common cryoprotectants were determined for high-pressure cryocooling of water in thick-walled plastic capillaries. The substantial reduction in the minimal concentrations by high-pressure cryocooling can be of significant use in high-throughput X-ray protein structure determination.

Online 28 April 2009

 

J. Appl. Cryst. (2009). 42, 531-534  [ doi:10.1107/S0021889809009157 ]

A sample cell for diffraction studies with control of temperature, relative humidity and applied electric field

F. Mo and K. Ramsøskar

Synopsis: This paper describes the design of various sample cells providing a controlled environment for small single crystals or epitaxial thin films during diffraction experiments.

Online 15 May 2009

 

J. Appl. Cryst. (2009). 42, 535-537  [ doi:10.1107/S0021889809013430 ]

The pseudo-single-crystal method: a third approach to crystal structure determination

T. Kimura, C. Chang, F. Kimura and M. Maeyama

Synopsis: A novel method that enables single-crystal diffraction data to be obtained from a powder sample is presented.

Online 15 May 2009

 

J. Appl. Cryst. (2009). 42, 538-539  [ doi:10.1107/S0021889809008309 ]

ReX: a computer program for structural analysis using powder diffraction data

M. Bortolotti, L. Lutterotti and I. Lonardelli

Synopsis: The ReX software provides a user-friendly environment for structural analysis using powder diffraction data.

Online 15 May 2009

 

J. Appl. Cryst. (2009). 42, 540-544  [ doi:10.1107/S0021889809012370 ]

HATODAS II - heavy-atom database system with potentiality scoring

M. Sugahara, Y. Asada, H. Shimada, H. Taka and N. Kunishima

Synopsis: HATODAS II, which provides comprehensive suggestions for the heavy-atom derivatization of protein crystals, is described.

Online 15 May 2009

 

J. Appl. Cryst. (2009). 42, 545-546  [ doi:10.1107/S0021889809014149 ]

Crystallization columns in a laboratory furnace

B. Cabric and N. Danilovic

Synopsis: A model of an air cooler in a laboratory furnace is presented. The setup allows for simultaneous regulation of different crystallization fronts and rates in crucible columns, enabling rapid acquisition of crystals in an undergraduate laboratory.

Online 2 May 2009

 

J. Appl. Cryst. (2009). 42, 547  [ doi:10.1107/S0021889809015660 ]

Re-evaluation of formulae for X-ray stress analysis in polycrystalline specimens with fibre texture. Erratum

R. Yokoyama and J. Harada

Synopsis: Errors in the paper by Yokoyama & Harada [J. Appl. Cryst. (2009), 42, 185-191] are corrected.

Online 2 May 2009

 

J. Appl. Cryst. (2009). 42, 548  [ doi:10.1107/S002188980901139X ]

Dominique Grebille (1957-2009)

Online 28 April 2009

 

J. Appl. Cryst. (2009). 42, 549  [ doi:10.1107/S0021889809017270 ]

Richard J. Weiss (1923-2008)

Online 15 May 2009