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New details on the structure of β-casein adsorbed layers, at the air–water interface, have been obtained using X-ray and neutron reflectivity. The experimental data are fitted well by a power law model and the results discussed in terms of the distribution of amino-acid sequences between trains, loops and tails. This distribution seems to be consistent with statistical theories established for flexible polymers. The trains are present in close proximity to the surface as a dense layer 8–9 A thick. At low surface coverage, the tail effect is negligible and the adsorbed layer is composed of nearly 60% amino-acid sequences in trains and the remaining in loops. When the bulk concentration is increased, a substantial part of the amino-acid residues has to be accommodated in loops and long tails; the adsorbed layer becomes more extended (80–100 A). A striking feature is observed for a high bulk concentration (10−1 wt.%): trains are forced to eject out of the interface.

The structure of water absorbed in polyHEMA is studied by X-ray diffraction in the vitreous state at 77 K as well as in the liquid state at room temperature. Molecular packing at the level of the first neighbors is found similar to that in bulk water but a distortion is observed at the level of the second neighbors which is attributed to the bending of the H bonds. From the widths of the Bragg peaks of the crystalline ices from the small-angle neutron scattering results, we deduce that the pore size and the interpore distance in the swollen polyHEMA are smaller than 30 A.

The crystal structure of the metastable β-phase of toluene is determined from single crystal X-ray diffraction data using a Monte-Carlo method coupled to a constrained leastsquares refinement. At 105 K β-toluene is orthorhombic (space group Pbcn ; a = 13.85 A, b = 11.42 A, c = 7.39 A ; Z = 8). Relations between the packing of the molecules in this modification and in the normal crystalline α-phase are discussed.

From measurement of the angular dependence of X-ray reflectivity on mercury and gallium it is concluded that the density variation in the liquid-vapor interface near the triple point cannot be represented by a step-like profile. Our results suggest non-monotonic profiles.

Amorphous films of some μm in thickness, prepared by low temperature condensation in an ultra-high vacuum onto liquid helium cooled substrates, have been studied in situ by using an X-ray diffractometer operating in a symmetrical reflection mode. The structure factor of gallium has been obtained over the wavevector range 1.3 to 16.1 A − by means of two wavelengths, Cr Kα and Mo Kα , monochromatized by balanced filters. The average number of nearest neighbours deduced from the well-resolved first maximum in the radial distribution function is equal to 9.3 atoms. The results are compared to those previously found by electron diffraction measurements on thin films and also to the structure of supercooled liquid.

Data reduction for EXAFS experiments on Fe80B20 and Fe80P20 metallic glasses has been achieved only after the iron phase shifts have been adjusted from pure α-iron spectra and the asymmetric nearest neighbor peak shape has been modelled. A comparison is made with the results of X-ray diffraction studies.

Quite recently, it has been found that X-ray absorption spectroscopy may be used as a probe for passive films. We measured the reflectivity vs. the incident energy from bulk samples and now report the preliminary results obtained from in situ measurements on passivated nickel.

The crystal and molecular structures of syndiotactic 2,4,6,8-tetraphenylnonane have been determined by direct methods and refinement from X-ray diffraction data. The unit cell is quadratic (space group I 4 1 /g) with, at room temperature, g  13.740, c  27.20 A, V = 5135.7 A, Z = 8 and contains one molecule in the asymmetric unit; the final weighted residual factor is r = 0.065 for 1541 observed reflexions. It is found that the aliphatic chain exhibits a gauche-gauche conformation in the middle of the chain.

A four-block mesogen composed of three chemically different moieties is synthesized. Its mesomorphic properties are characterized by optical microscopy, differential thermal analysis and X-ray diffraction at small angles, demonstrating a smectic C structure between 92°C and 111°C. The notion of a polyphile is defined and the expected peculiarities of such compounds are emphasized.

A copper complex of a phthalocyanine substituted with four benzo-15-crown-5 1,Cu and the corresponding dihydrogeno-derivative 1,H2 were synthesized. X-ray determinations at small angles permitted us to characterize two types of condensed phases. Solid phases with orthorhombic structure were found for 1,H2 and for 1,Cu (a=20.5, b= 18, c=4.2 A). In these forms, two-dimensional rectangular arrays of substituted phthalocyanines lead to corrugated planes. Phthalocyanine moieties are superposed in an eclipsed conformation and the crown-ether macrocycles form channels. Metastable mesophases could also be characterized by X-ray diffraction. In this case, only two broad lines at 20.8 and 8.2 A and two halos at 3.5 and 4.2 A are observed for 1,Cu. The dihydrogeno-derivative leads to a similar pattern but only one halo is noticed at 4.2 A. The mesophases are constituted of two-dimensional square lattices superposed in a staggered conformation.