A review. Diffraction methods are a powerful tool to investigate the crystal structure of organic compounds in general and their hydrates in particular. The laboratory standard technique of single crystal X-ray diffraction gives information about the molecular conformation, packing and hydrogen bonding in the crystal structure, while powder X-ray diffraction on bulk material can trace hydration...

this work has setup to determine the effects of a solvent on the structure and properties of polypropylene fibres with different physical structures. samples of continuous filament yarns with different physical structures (partially oriented (poy) and drawn yarns) are treated with decahydronaphthalene (decalin) at 28, 55, 75 and 95oc. at 95oc, the samples are dissolved completely in decalin and...

We report the observation of superstructures associated with the oxygen 2p states in two prototypical manganites using x-ray diffraction at the oxygen K edge. In the stripe order system Bi0.31Ca0.69MnO3, hole-doped O states are orbitally ordered, at the same propagation vector as the Mn orbital ordering, but no oxygen charge stripes are found at this periodicity. In La7/8Sr1/8MnO3, we observe a...

The existence of an orientationally disordered cubic phase of solid ethanol is revealed by x-ray diffraction and Raman spectroscopic measurements. Such a phase, whose existence was postulated some time ago on the basis of specific-heat measurements, is produced by quenching below some 95 K a plastic crystal formed upon melting and subsequent annealing of the topologically disordered ~glassy! so...

Using surface x-ray diffraction, we have determined the structure of liquid Bi monolayers on Cu(111) for a range of coverages. By combining diffuse scattering data from the liquid with information from the substrate scattering, the ordering properties of Bi have been fully determined. Even though the substrate is hexagonal, we find that the liquid does not show hexatic order but has an orthorho...

We have observed large-amplitude strain waves following a rapid change in density of InSb due to nonthermal melting. The strain has been measured in real time via time-resolved x-ray diffraction, with a temporal resolution better than 2 ps. The change from the solid to liquid density of the surface layer launches a high-amplitude strain wave into the crystalline material below. This induces an ...

The energy landscape of Mg(BH(4))(2) under pressure is explored by ab initio evolutionary calculations. Two new tetragonal structures, with space groups P4 and I4(1)/acd, are predicted to be lower in enthalpy by 15.4 and 21.2 kJ/mol, respectively, than the earlier proposed P4(2)nm phase. We have simulated x-ray diffraction spectra, lattice dynamics, and equations of state of these phases. The d...

We use time-resolved optical reflectivity and x-ray diffraction with femtosecond resolution to study the dynamics of the structural order parameter of the charge density wave phase in TiSe2. We find that the energy density required to melt the charge density wave nonthermally is substantially lower than that required for thermal suppression and is comparable to the charge density wave condensat...

We employ time-resolved resonant x-ray diffraction to study the melting of charge order and the associated insulator-to-metal transition in the doped manganite Pr_{0.5}Ca_{0.5}MnO_{3} after resonant excitation of a high-frequency infrared-active lattice mode. We find that the charge order reduces promptly and highly nonlinearly as function of excitation fluence. Density-functional theory calcul...

We present coherent speckled x-ray diffraction patterns obtained from a monolayer of surface atoms. We measured both the specular anti-Bragg reflection and the off-specular hexagonal reconstruction peak for the Au(001) surface reconstruction. We observed fluctuations of the speckle patterns even when the integrated intensity appears static. By autocorrelating the speckle patterns, we were able ...