Hard X-ray lens-less microscopy raises hopes for a non-invasive quantitative imaging, capable of achieving the extreme resolving power demands of nanoscience. However, a limit imposed by the partial coherence of third generation synchrotron sources restricts the sample size to the micrometer range. Recently, X-ray ptychography has been demonstrated as a solution for arbitrarily extending the fi eld of view without degrading the resolution. Here we show that ptychography, applied in the Bragg geometry, opens new perspectives for crystalline imaging. The spatial dependence of the three-dimensional Bragg peak intensity is mapped and the entire data subsequently inverted with a Bragg-adapted phase retrieval ptychographical algorithm. We report on the image obtained from an extended crystalline sample, nanostructured from a silicon-on-insulator substrate. The possibility to retrieve, without transverse size restriction, the highly resolved three-dimensional density and displacement fi eld will allow for the unprecedented investigation of a wide variety of crystalline materials, ranging from life science to microelectronics.

Interfaces between polarity domains in nitride semiconductors, the so-called Inversion Domain Boundaries (IDB), have been widely described, both theoretically and experimentally, as perfect interfaces (without dislocations and vacancies). Although ideal planar IDBs are well documented, the understanding of their configurations and interactions inside crystals relies on perfect-interface assumptions. Here, we report on the microscopic configuration of IDBs inside n-doped gallium nitride wires revealed by coherent X-ray Bragg imaging. Complex IDB configurations are evidenced with 6 nm resolution and the absolute polarity of each domain is unambiguously identified. Picoscale displacements along and across the wire are directly extracted from several Bragg reflections using phase retrieval algorithms, revealing rigid relative displacements of the domains and the absence of microscopic strain away from the IDBs. More generally, this method offers an accurate inner view of the displacements and strain of interacting defects inside small crystals that may alter optoelectronic properties of semiconductor devices.

Coherent diffraction imaging (CDI) on Bragg reflections is a promising technique for the study of three-dimensional (3D) composition and strain fields in nanostructures, which can be recovered directly from the coherent diffraction data recorded on single objects. In this article we report results obtained for single homogeneous and heterogeneous nanowires with a diameter smaller than 100 nm, for which we used CDI to retrieve information about deformation and faults existing in these wires. The article also discusses the influence of stacking faults, which can create artefacts during the reconstruction of the nanowire shape and deformation.

Biomineralization integrates complex processes leading to an extraordinary diversity of calcareous biomineral crystalline architectures, in intriguing contrast with the consistent presence of a sub-micrometric granular structure. Hence, gaining access to the crystalline architecture at the mesoscale, that is, over a few granules, is key to building realistic biomineralization scenarios. Here we provide the nanoscale spatial arrangement of the crystalline structure within the 'single-crystalline' prisms of the prismatic layer of a Pinctada margaritifera shell, exploiting three-dimensional X-ray Bragg ptychography microscopy. We reveal the details of the mesocrystalline organization, evidencing a crystalline coherence extending over a few granules. We additionally prove the existence of larger iso-oriented crystalline domains, slightly misoriented with respect to each other, around one unique rotation axis, and whose shapes are correlated with iso-strain domains. The highlighted mesocrystalline properties support recent biomineralization models involving partial fusion of oriented nanoparticle assembly and/or liquid droplet precursors.

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A compact scanning force microscope has been developed for in situ combination with nanofocused X-ray diffraction techniques at third-generation synchrotron beamlines. Its capabilities are demonstrated on Au nano-islands grown on a sapphire substrate. The new in situ device allows for in situ imaging the sample topography and the crystallinity by recording simultaneously an atomic force microscope (AFM) image and a scanning X-ray diffraction map of the same area. Moreover, a selected Au island can be mechanically deformed using the AFM tip while monitoring the deformation of the atomic lattice by nanofocused X-ray diffraction. This in situ approach gives access to the mechanical behavior of nanomaterials.

OPERA is part of the CNGS project and it is an experiment dedicated to the observation of long-baseline nu(mu) into nu(tau) oscillations through tau appearance. Resistive Plate Chambers (RPCs) with bakelite electrodes are used to instrument the 2 cm gaps between the magnetized iron slabs of the two spectrometers. The RPC installation ended in may 2004 on the first spectrometer and in march 2005 on the second one. Before the installation, every RPC is subjected to a complete test chain in order to reject the poorer quality detectors. The tests are performed in dedicated facilities to ensure the proper RPC gluing, to measure its electrical properties and to verify the response to cosmic rays and the intrinsic noise levels. We have also tested the long term stability of real size OPERA RPC prototypes operated at cosmic ray fluxes for more than one year. On small size prototypes we are performing studies on the gas' mixtures in order to reduce the total charge released in the gas for each detector count. The validation of the installed RPCs has been performed with pure nitrogen. A small part of them has been also tested with the gas mixture Ar/C2H2F4/i - C4H10/SF6 = 75.4/20/4/0.6

We report on the quantitative determination of the strain map in a strained Silicon-On-Insulator (sSOI) line with a 200 × 70 nm 2 cross-section. In order to study a single line as a function of time, we used an X-ray nanobeam with relaxed coherence properties as a compromise between beam size, coherence and intensity. We demonstrate how it is possible to reconstruct the line deformation at the nanoscale, and follow its evolution as the line relaxes under the influence of the X-ray nanobeam.PACS numbers: 41.50.+h, 68.60.Bs New applications in optoelectronic and electronic semiconductor devices have been achieved by a careful control of strain at the nanoscale level. Several physical properties such as charge carrier mobility in transistors and emission wavelength in quantum dots or well heterostructure have been advantageously improved by applying strain fields adapted to the materials band structure, orientation and doping features [1][2][3][4].The measurement of these strain fields has required the development of dedicated techniques with adapted spatial and strain resolution. Electronic imaging techniques have seen tremendous developments and outstanding achievements [5], but are always limited by the preparation of thin foil that can considerably relieve internal stress in nanostructures. Very recently, X-ray diffraction has taken profit of the highly brilliant and coherent radiation provided by synchrotron sources [6]. Moreover, the optimization of dedicated focusing optics (compound refractive lenses [7], Fresnel Zone Plate (FZP) [8,9], Kirkpatrick-Baez mirrors [10,11]) has allowed the use of nanobeams, increasing the spatial resolution of diffraction measurements. This also allowed the use of coherent X-ray diffraction imaging (CXDI) for structure (shape, size) and strain determination of single nano-objects [12][13][14][15][16].In this letter, we illustrate how the strain of a single strained silicon nanostructure changes during irradiation with x-rays, as a function of measurement time using a partially coherent X-ray nanobeam. Strained SiliconOn-Insulator (sSOI) lines are considered due to their strong interest for enhancing the carrier mobility in metal oxide semiconductors field-effect-transistors (MOSFET) devices [17,18].Silicon lines were etched from a (001) oriented sSOI substrate made by a wafer bonding technique from the Si deposition on a SiGe virtual substrate imposing a biaxial strain, as described in [19]. Lines in tensile strain ( yy = +0.78%) are oriented along the [110] direction which corresponds to the usual direction of n-MOSFET channels for which electron transport is improved. The strain relaxes elastically along [110], i.e. perpendicularly to the lines [18]. An in-plane misorientation of about 1 o is used between the strained Si lines and the Si substrate in order to separate the line and substrate Bragg peaks. The sSOI lines have a width W=225 nm and a height H=70 nm (Fig. 1) and lie on a 145 nm SiO 2 layer. The distance d between two adjacent lines is about 775 nm. Grazing-incid...