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An in situ small-angle x-ray scattering study of the nanoparticle displacement in a self-assembled monolayer as a function of a supporting membrane strain is presented. The average nanoparticle spacing is 6.7 nm in the unstrained state and increases in the applied force direction, following linearly the membrane strain which reaches the maximum value of 11%. The experimental results suggest a continuous mutual shift of the nanoparticles and their gradual separation with the growing stress rather than nanoparticle islands formation. No measurable shift of the nanoparticles was observed in the direction perpendicular to the applied stress.

The ordered nanoparticle monolayers and multilayers over macroscopic areas were prepared by the modified LangmuirBlodgett method. Using this approach, the nanoparticle monolayer is formed on the water surface by compression and subsequently it is transferred onto the substrate by a controlled removal of the water subphase. The ordering and homogeneity of the prepared mono-and multilayers was studied by scanning electron microscope (SEM), grazing-incidence small-angle X-ray scattering (GISAXS) and X-ray reflectivity (XRR) techniques. From the results it follows that an ordered nanoparticle monolayer was formed over a large area. For the multilayer, the layering and lateral ordering of each layer was confirmed by XRR and SEM performed after the deposition of each nanoparticle layer.

Methods have been developed for the calibration of specimen temperature and of specimen displacement caused by the thermal expansion of the specimen holder in a heating/cooling chamber equipped with a strip or plate heater mounted on an X-ray diffractometer. For the temperature calibration two methods were proposed. One method relies on X-ray diffraction measurements of thermal lattice strains, whereas the other method is based on resistance thermometry. The method proposed for the determination of the temperaturedependent specimen displacement is based on the measurement of diffractionline positions of the specimen employing two diffraction geometries, one being sensitive to the specimen displacement and the other being insensitive to the specimen displacement. The thermal displacement of the specimen due to thermal expansion of the specimen holder is significant and was determined as about 38 mm per 100 K. research papers J. Appl. Cryst. (2006). 39, 194-201 M. Wohlschlö gel et al. Calibration of a heating/cooling chamber 195 research papers J. Appl. Cryst. (2006). 39, 194-201 M. Wohlschlö gel et al. Calibration of a heating/cooling chamber 201

Real-time reassembly of an ordered nanoparticle monolayer due to UV-photolysis of the surfactant shell of nanoparticles was observed. The technique of grazing-incidence small-angle X-ray scattering provided the possibility to track in situ the nanoparticle pair correlation function of the sample processed in a UV-ozone reactor. The analysis revealed a total shift of approximately 1 nm of the nanoparticle nearest-neighbor distance. The temporal evolution of the interparticle distance proved to be the first-order process governed by the UV-photolysis and described by a single-exponential decay function. The nanoparticles tend to agglomerate into a labyrinth-like structure with a typical length scale of some 30 nm.