Journal of Applied Crystallography

Volume 36, Part 4 (August 2003)

	Cover illustration: Protein crystals in a 2 µl gelled microbatch drop dispensed automatically under oil. Courtesy of A. Moreno, E. Saridakis & N. E. Chayen [J. Appl. Cryst. (2002), 35, 140-142].

• research papers
• short communications
• computer programs
• computer program abstracts
• meetings

research papers

J. Appl. Cryst. (2003). 36, 961-966  [ doi:10.1107/S0021889803008410 ] Structure of magnetic poly(oxyethylene)-siloxane nanohybrids doped with FeII and FeIII N. J. O. Silva, K. Dahmouche, C. V. Santilli, V. S. Amaral, L. D. Carlos, V. de Z. Bermudez and A. F. Craievich Synopsis: Hybrid organic-inorganic nanocomposites doped with FeII and FeIII ions and exhibiting interesting magnetic properties have been obtained by the sol-gel process. The different magnetic features between FeII- and FeIII-doped samples are consistent with the structural differences revealed by small-angle X-ray scattering. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 967-969  [ doi:10.1107/S0021889803008422 ] Polymer hydration and microphase decomposition in poly(N-vinylcaprolactam)-water complex V. Lebedev, G. Török, L. Cser, W. Treimer, D. Orlova and A. Sibilev Synopsis: The poly(N-vinylcaprolactam)-D2O system has been investigated by small-angle neutron scattering (SANS) at T = 296-316 K to identify the structural features of the coil-globule transformation. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 970-975  [ doi:10.1107/S002188980300846X ] Small-angle neutron scattering and differential scanning calorimetry study of associative behaviour of branched poly(ethylene oxide)/poly(propylene oxide) copolymer in aqueous solution J. Plestil, H. Pospísil, A. Sikora, I. Krakovský and A. I. Kuklin Synopsis: Association behaviour of an amphiphilic X-shaped octablock poly(ethylene oxide)/poly(propylene oxide) copolymer with hydrophobic (PPO) terminal blocks in aqueous solutions was studied using small-angle neutron scattering and differential scanning calorimetry. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 976-981  [ doi:10.1107/S0021889803008471 ] Transformation of cubic symmetry for spherical microdomains from face-centred to body-centred cubic upon uniaxial elongation in an elastomeric triblock copolymer K. Imaizumi, T. Ono, T. Kota, S. Okamoto and S. Sakurai Synopsis: Small-angle X-ray scattering experimental observation of the transformation of cubic symmetry from face-centred cubic (f.c.c.) to body-centred cubic (b.c.c.) for spherical microdomains upon uniaxial stretching of poly(1,3-cyclohexadiene)-block-poly(ethylene-co-but-1-ene)-block-poly(1,3-cyclohexadiene) triblock copolymer is reported. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 982-985  [ doi:10.1107/S0021889803008483 ] Singular value decomposition analysis of time-resolved small-angle X-ray scattering during morphological transition in a block copolymer S. Okamoto and S. Sakurai Synopsis: An as-cast specimen of a polystyrene-block-poly(ethylene-alt-butylene)-block-polystyrene (SEBS) triblock copolymer with lamellar microdomains underwent the temperature jump from 363 to 403 K and the morphological transition from lamellae to cylinders was observed as a function of time by the TR-SAXS technique. Singular value decomposition (SVD) analysis strongly suggested the existence of a third basis component of the X-ray scattering profiles, thus supporting that there is an intermediate state during the transition from lamellae to cylinders. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 986-990  [ doi:10.1107/S0021889803008495 ] Time-resolved small-angle X-ray scattering and wide-angle X-ray diffraction studies on the nanostructure of melt-processable molecular composites J. Janicki Synopsis: The nanostructure and thermal behaviour of novel melt-processable molecular composites were examined by real-time synchrotron small-angle X-ray scattering and wide-angle X-ray diffraction methods, and differential scanning calorimetry. The synthesized oligoester, with low melting temperature (391 K), exhibits the ability to form a thermotropic mesophase. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 991-994  [ doi:10.1107/S0021889803008513 ] Combined small- and wide-angle X-ray scattering study of early stages of polymer crystallization P. Panine, V. Urban, P. Boesecke and T. Narayanan Synopsis: Simultaneous time-resolved small-angle and wide-angle X-ray scattering techniques were used to probe the early stages of melt crystallization in low-density polyethylene. Both the scattering invariant and the degree of crystallinity were found to evolve by Avrami-type growth law. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 995-999  [ doi:10.1107/S0021889803008525 ] Co-crystallization of poly(ethylene-butene) copolymers and paraffin molecules in decane studied with small-angle neutron scattering A. Radulescu, D. Schwahn, D. Richter and L. J. Fetters Synopsis: Systematic small-angle neutron scattering investigations of different polymer-paraffin systems have shown that PEB-n copolymers are selective in their paraffin-modification capacity, depending on the crystalline degree which is tuned by the number `n' of ethyl side branches/100 backbone C atoms. Two mechanisms of polymer-paraffin interaction have been identified: on the one hand, co-crystallization of the paraffin and copolymer within thin platelets occurs as a consequence of a good fit between the self-assembling properties of the investigated polymer/paraffin pairs (PEB-7.5/C36 and PEB-11/C24); on the other hand, primordial polymer aggregates act as a template for a subsequent paraffin crystallization when the polymer has a higher self-assembling point (PEB-7.5/C24) than the paraffin. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 1000-1005  [ doi:10.1107/S0021889803013761 ] A small-angle neutron scattering investigation of rigid polyelectrolytes under shear E. Mendes, S. Viale, O. Santin, M. Heinrich and S. J. Picken Synopsis: Solutions of a rigid polyelectrolyte molecule, sulfo-poly(phenyleneterephthalamide) (SPTTA), in deuterated water have been investigated using small-angle neutron scattering. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 1006-1012  [ doi:10.1107/S0021889803008574 ] Microstructure of radiation-damaged zircon under pressure S. Ríos and T. Boffa-Ballaran Synopsis: The microstructure of defective crystalline domains embedded in heavily amorphized zircon is studied as a function of pressure, up to 7 GPa. Results are used to gain insight into the topology of amorphous zircon. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 1013-1018  [ doi:10.1107/S0021889803008860 ] Determination of compaction and surface in mesostructured materials using SAXS F. Né and T. Zemb Synopsis: An experimental method to determine simultaneously the compaction and the total specific area between an inorganic oxide network and a material of low electronic density is presented. This method is applicable when both the Porod limit and the invariant can be extracted from the small-angle X-ray scattering pattern on an absolute scale. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 1019-1025  [ doi:10.1107/S0021889803009087 ] Image analysis of transmission electron micrographs of semicrystalline polymers: a comparison with X-ray scattering results H. G. Haubruge, X. A. Gallez, B. Nysten and A. M. Jonas Synopsis: The image analysis of TEM micrographs shows a quantitative correlation with SAXS measurements of the characteristic distances in semi-crystalline polymers. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 1026-1029  [ doi:10.1107/S0021889803009075 ] HRTEM study of orthorhombic zirconia in MgO-PSZ Z. Liu, Y. Bando, J. Drennan and A. E. C. Spargo Synopsis: Of the three orthorhombic ZrO2 structures, with space groups Pbcm, Pbc21 and Pbca, it is shown that the crystal structure of orthorhombic ZrO2, formed in magnesia partially stabilized zirconia as a result of polishing, can only have space group Pbcm. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 1030-1039  [ doi:10.1107/S002188980300935X ] In situ high-temperature powder diffraction study of reversible phase transitions in decagonal Al71.2Co12.8Ni16 C. Soltmann, C. Beeli, R. Lück and W. Gander Synopsis: Precise high-temperature synchrotron measurements of the cell parameters of decagonal Al71.2Co12.8Ni16 have enabled the investigation of the anisotropic thermal expansion behaviour in the range of the type I S1 phase transition. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 1040-1049  [ doi:10.1107/S0021889803010136 ] Synchrotron texture analysis with area detectors H.-R. Wenk and S. Grigull Synopsis: Practical aspects of texture measurement and data processing procedures to enable the application of orientation distribution function reconstruction methods in synchrotron experiments are described. Previous applications are reviewed and some opportunities for synchrotron texture analysis are highlighted based on case studies on different materials. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 1050-1055  [ doi:10.1107/S0021889803010276 ] Theoretical versus experimental geometries in S-bridged manganese carbonyl complexes J. F. Van der Maelen Uría, J. Ruiz and S. García-Granda Synopsis: The experimental geometry obtained from single-crystal X-ray diffraction for a number of binuclear S-bridged manganese complexes is compared with the results of theoretical calculations. The mean square deviation for bond lengths (angles) was found to be between 0.046 Å (1.1°) and 0.004 Å (0.7°) depending on the theoretical model used. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 1056-1061  [ doi:10.1107/S0021889803010410 ] Effects of the choice of different ionization level for scattering curves and correction for small preferred orientation in Rietveld refinement: the MgAl2O4 test case P. Ballirano Synopsis: The effects of the choice of oxygen scattering curves with different ionization levels and of the number of spherical harmonics terms used to correct for preferred orientation are discussed in the case of the Rietveld refinement of MgAl2O4 spinel. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 1062-1068  [ doi:10.1107/S0021889803011063 ] Generation of grain maps by an algebraic reconstruction technique H. F. Poulsen and X. Fu Synopsis: Embedded grain boundaries in a polycrystal are mapped non-destructively by hard X-rays and an iterative algebraic algorithm. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 1069-1074  [ doi:10.1107/S002188980301104X ] Identification of aggregates of magnetic nanoparticles in ferrofluids at low concentrations D. Eberbeck, A. Lange and M. Hentschel Synopsis: The size distribution and aggregation of particles in ferrofluids were quantitatively determined by means of small-angle scattering. Online 19 July 2003

J. Appl. Cryst. (2003). 36, 1075-1081  [ doi:10.1107/S0021889803011051 ] Precise measurement of the lattice parameters of -Al2O3 in the temperature range 4.5-250 K using the Mössbauer wavelength standard M. Lucht, M. Lerche, H.-C. Wille, Y. V. Shvyd'ko, H. D. Rüter, E. Gerdau and P. Becker Synopsis: The lattice parameters of -Al2O3 have been measured in a temperature range from 4.5 to 250 K with a relative accuracy of better than 6 × 10-6. Online 19 July 2003

short communications

J. Appl. Cryst. (2003). 36, 1082-1084  [ doi:10.1107/S0021889803010288 ] Structural analysis of excess-anion C-type rare earth oxide: a case study with Gd1-xCexO1.5+x/2 (x = 0.20 and 0.40) V. Grover, S. N. Achary and A. K. Tyagi Synopsis: Structural analysis of anion-rich C-type Gd2O3 was carried by the Rietveld refinement of the powder X-ray diffraction data for compositions Gd0.8Ce0.2O1.60 and Gd0.6Ce0.4O1.70. The details of these two compositions are explained and compared with both the CeO2 structure and the Gd2O3 structure, i.e. the end member. Online 19 July 2003

computer programs

J. Appl. Cryst. (2003). 36, 1098-1100  [ doi:10.1107/S0021889803010756 ] PSILAM: a program for the calculation and graphical representation of multiple-diffraction peak location plots E. Rossmanith Synopsis: PSILAM makes possible the calculation and graphical representation of multiple-diffraction - peak location plots and can be applied to X-rays as well as to neutrons. Online 19 July 2003

computer program abstracts

J. Appl. Cryst. (2003). 36, 1101-1102  [ doi:10.1107/S0021889803011373 ] BEAM-ish 2.0: a graphical user interface for the physical characterization of macromolecular crystals J. Lovelace and G. E. O. Borgstahl Synopsis: BEAM-ish 2.0 is a graphical user interface that manages the processing of multiple super-fine -sliced diffraction images for crystal quality analysis, seamlessly links together several programs, provides a central storage directory for files generated at all stages of the analysis, and allows the user to visualize and check the results. Online 19 July 2003

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