The structure of the Au/Si(557) surface is determined from three-dimensional x-ray diffraction measurements, which directly mandate a single Au atom per unit cell. We use a "heavy atom" method in which the Au atom images the rest of the structure. Au is found to substitute for a row of first-layer Si atoms in the middle of the terrace, which then reconstructs by step rebonding and adatoms. The ...

We present a solution to a long-standing basic problem encountered in the theory of structure determination of crystalline media from x-ray diffraction experiments; namely, the problem of determining phases of the diffracted beams.

Antiferromagnetic spintronics is a rapidly growing field, which actively introduces new principles of magnetic storage. Despite that, most applications have been suggested for collinear antiferromagnets. In this study, we consider an alternative mechanism based on long-range helical order, which allows for direct manipulation of the helicity vector. As the helicity of long-range homogeneous spi...

The Powder Diffraction File TM (PDF) is a comprehensive materials database that is the key source of reference powder diffraction data for identification and analysis of materials; from natural minerals and high-tech ceramics, to metals and alloys, and pharmaceuticals. New developments in X-ray analysis, and advances in scientific research, have dramatically influenced the range of data present...

X-ray, neutron and electron diffraction methods are widely used for the investigation of crystals. Each of these techniques has their own advantages in terms of element sensitivity, sample size requirements etc. and are chosen accordingly for structure determinations. A less obvious difference lies in the spatial resolution of these diffraction techniques. Here, we show that electron diffractio...

Abstract: powerful method for the characterization of microstructures of crystalline materials in terms of crystallite size anddislocation structures. In this paper the effect of the sliding on the microstructure of A356 in the as-cast and heattreated conditions are studied, The X-ray phase analysis shows that with increasing applied load, the dislocationdensity is increased, whereas the crysta...

The magnetite (Fe3O4) – agar nanocomposite was prepared by co-precipitation of Fe (III) and Fe (II) ions for the first time. The obtained samples were characterized by x-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. FT-IR results confirm the formation of Fe3O4 nanoparticles...