Publications

Browse the list of publications in the library for ID31.

The review committees are paying increasing attention to the quality of publications resulting from work carried out at the ESRF. Please remember to note on the proposal form the complete references of your most recent papers appearing in print, based on measurements made at the ESRF. Remember to send a reprint for the Joint ESRF/ILL library.

Experimental reports

Browse the list of exprimental reports for ID31.

If you have been allocated beam time for an experiment you are required to provide a report of your experiment. Deadlines for submissions of experimental reports are: 1st March for experiments carried out up to July of the previous year 1st September for experiments carried out up to January. If you are submitting a proposal for a new project, or to continue a project for which you have previously been allocated beam time, you must attach a report, if necessary, a preliminary report on your measurements. For detailed instructions for preparing your report, please look at the user office pages.

Recent ID31 highlights

Revision of the structure of Cs₂CuSi₅O₁₂ leucite as orthorhombic Pbca

A. M. T. Bell, K. S. Knight, C. M. B. Henderson and A. N. Fitch

Acta. Cryst., B66, 51 (2010).

The crystal structure of a hydrothermally synthesized leucite analogue Cs₂CuSi₅O₁₂ has been determined and refined using the Rietveld method from high-resolution synchrotron X-ray and neutron powder diffraction data. This structure is based on the topology and cation-ordering scheme of the Pbca leucite structure of Cs₂CdSi₅O₁₂, and exhibits five ordered Si sites and one ordered Cu tetrahedrally coordinated (T) site. This structure for Cs₂CuSi₅O₁₂ is topologically identical to other known leucite structures and is different from that originally proposed by Heinrich & Baerlocher [(1991), Acta Cryst. C47, 237-241] in the tetragonal space group P4₁2₁2. The crystal structure of a dry-synthesized leucite analogue Cs₂CuSi₅O₁₂ has also been refined; this has the Ia-3d cubic pollucite structure with disordered T sites.

Anisotropic microstrain broadening of minium, Pb₃O₄, in a high-pressure cell: interpretation of line-width parameters in terms of stress variations

A. Leineweber and R. E. Dinnebier

J. Appl. Cryst., 43, 17 (2010).

The diffraction-line broadening exhibited by three different Pb₃O₄ phases was studied at ambient and elevated pressures. The broadening indicates strongly anisotropic microstrain, which was interpreted in terms of (local) stress variations in association with strongly anisotropic elastic properties. In particular, making use of the anisotropic compressibility of Pb₃O₄ determined on the basis of the present data, the pressure fluctuations in the employed diamond anvil cell due to non-hydrostatic conditions of the sample were estimated.

Molecular and crystalline structures of three (S)-4-alkoxycarbonyl-2-azetidinones containing long alkyl side chains from synchrotron X-ray powder diffraction data

L. E. Seijas, A. J. Mora, G. E. Delgado, F. López-Carrasquero, M. E. Báez, M. Brunelli and A. N. Fitch

Acta. Cryst., B65, 724 (2009).

The (S)-4-alkoxo-2-azetidinecarboxylic acids are optically active β-lactam derivatives of aspartic acid, which are used as precursors of carbapenem-type antibiotics and poly-β-aspartates. The crystal structures of three (S)-4-alkoxo-2-azetidinecarboxylic acids with alkyl chains with 10, 12 and 16 C atoms were solved using parallel tempering and refined against the X-ray powder diffraction data using the Rietveld method. The azetidinone rings in the three compounds display a pattern of asymmetrical bond distances and an almost planar conformation; these characteristics are compared with periodic solid-state, gas-phase density-functional theory (DFT) calculations and MOGUL average bond distances and angles from the CSD. The compounds pack along [001] as corrugated sheets separated by approximately 4.40 Å and connected by hydrogen bonds of the type N-H···O.

Charge ordering driven metal-insulator transition in the layered cobaltite HoBaCo₂O_5.5

L. Malavasi, M. Brunelli, Y. Diaz-Fernandez, B. Pahari, and P. Mustarelli.

Phys. Rev. B, 80, 153102 (2009).

In this Brief Report we report high-resolution synchrotron x-ray diffraction and x-ray pair-distribution-function analysis as a function of temperature on the HoBaCo₂O_5.5 cobaltite. These investigations provided a direct evidence of a structural phase transition from an orthorhombic to a monoclinic phase in the HoBaCo₂O_5.5 layered cobaltite which occurs concomitantly with the metal to insulator transition. The structural data suggest a possible charge ordered state in the monoclinic phase which may be responsible for the insulating character at low temperature.

[Al₄(OH)₂(OCH₃)₄(H₂N-bdc)₃]·x H₂O: A 12-Connected Porous Metal-Organic Framework with an Unprecedented Aluminum-Containing Brick

T. Ahnfeldt, N. Guillou, D. Gunzelmann, I. Margiolaki, T. Loiseau, G. Férey, J. Senker and N. Stock.

Angew. Chem. Int. Ed., 48, 5163 (2009).

Al together now! A new stable aluminum aminoterephthalate system contains octameric building blocks that are connected by organic linkers to form a 12-connected net (see picture). The structure adopts a cubic centered packing motive in which octameric units replace individual atoms, thus forming distorted octahedral (red sphere) and tetrahedral cages (green spheres) with effective accessible diameters of 1 and 0.45 nm, respectively.

Structure and conformational analysis of a bidentate pro-ligand, C₂₁H₃₄N₂S₂, from powder synchrotron diffraction data and solid-state DFTB calculations

 E. E. Ávila, A. J. Mora, G. E. Delgado, R. R. Contreras, L. Rincón, A. N. Fitch and M. Brunelli.

Acta. Cryst., B65, 639 (2009).

The crystalline structure of ethyl 1',2',3',4',4a',5',6',7'-octahydrodispiro[cyclohexane-1,2'-quinazoline-4',1''-cyclohexane]-8'-carbodithioate, C₂₁H₃₄N₂S₂, a bidentate pro-ligand with a coordination sphere of the type [NS]^1-, was solved and refined from synchrotron powder diffraction data, and compared with in-vacuum density-functional theory (DFT) B3LYP/6-311G* and solid-state density-functional tight-binding (DFTB) theoretical calculations.

Response of the Crystal Structure and Electronic Properties to Calcium Substitution in NdFeAsO

 A. Marcinkova, E. Suard, A. N. Fitch, S. Margadonna and J. W. G. Bos

Chem. Mater., 21, 2967 (2009).

Synchrotron X-ray, neutron powder diffraction, magnetic susceptibility, and electrical resistance measurements were used to investigate the Nd_1−xCa_xFeAsO series. The solubility of calcium is limited to 0 ≤ x ≤ 0.05. Within this interval, the iron arsenide layer contracts linearly in agreement with the hole doping of anti-bonding iron 3d-orbital states at the Fermi level. Depletion of the free charge carriers results in a transition to semiconducting behaviour. The iron spin-density wave (SDW) transition temperature is reduced from 140 K (x = 0) to 125 K (x = 0.025) to 130 K (x = 0.05). Long-range SDW ordering is only observed in neutron diffraction concomitant with that of the rare-earth sublattice (T_N,Nd ≈ 2 K), revealing that the Nd ordering enhances the ordered Fe moment in spite of the large difference in ordering temperature. The transition to semiconducting behaviour results in a dramatic change in the magnitude and field dependence of the magnetoresistance (MR), which is much reduced (R/R₀ = 1.6 for x = 0, 1.03 for x = 0.025, and 1.06 for x = 0.05 at 5 K and in 9 Tesla) and becomes more linear for x > 0. Finally, MR is first observed at the onset of the structural P4/nmm → Cmma transition, and increases more rapidly below T_SDW, providing further evidence that the structural phase transition and SDW are linked.