Defocused travelling fringes in a scanning triple-Laue X-ray interferometry setup

The measurement of the silicon lattice parameter by a separate-crystal triple-Laue X-ray interferometer is a key step for the realization of the kilogram by counting atoms. Since the measurement accuracy is approaching nine significant digits, a reliable model of the interferometer operation is required to quantify or exclude systematic errors. This paper investigates both analytically and experimentally the effect of the defocus (the difference between the splitter-to-mirror and analyser-to-mirror distances) on the phase of the interference fringes and the measurement of the lattice parameter.

On the symmetry of magnetic structures in terms of the fibre bundles

The paper concerns the application of the fibre bundle approach to the description of the magnetic structures and their symmetry groups. Hence the explicit formulas describing both the variety of magnetic structures and their symmetry groups have been derived. The assumption was made that the bundle sections correspond to magnetizations of the separate crystal planes multiplied by a certain Gaussian factor defined in ℝ3, the last factor making the problem continuous and more physical.

Image Restoration of One-Dimensional HgTe Crystals Formed within Single Walled Carbon Nanotubes

Restored high resolution transmission electron microscopy (HRTEM) images have been recorded from 1D semiconductor crystals formed within narrow diameter (ca. 1.4 nm) single walled carbon nanotubes (SWNTs). Two unique projections were obtained from separate crystal fragments encapsulated within separate nanotubes that has facilitated the reconstruction of the three dimensional arrangement of atoms within the two encapsulated fragments.

The Crystal Size and Morphology of Silicalite as Influenced by Gel Nucleation Temperature, Alkalinity and Sodium-Chloride Concentration

The influence of sodium chloride, nucleation temperature and alkalinity on crystal size and product morphology of silicalite is described for crystallizations at temperatures of about 170�C. Addition of sodium chloride and increasing alkalinity produce crystals with less intergrowth. Nucleating the gel at 90�C before crystallization significantly reduces crystal size. The intergrowths on the faces of silicalite can be separated and features of the interlocking of separate crystal entities revealed.

VII. Colours in metal glasses, in metallic films, and in metallic solutions.—II

This paper is an extension of a previous memoir on the “Colours in Metal Glasses and in Metallic Films”; it is concerned with the application of mathematical analysis, akin to that already there developed, to the explanation and coordination of the colours which certain metals are, under a great variety of circumstances, capable of causing. From observations on gold and copper ruby glasses, it has been shown that the first stage in the formation of a crystal of those metals is the small sphere; and from observations on the growth of sulphur crystals in CS 2 , Vogelsang arrived at the conclusion that the small sphere is always the first stage in the formation of a crystal. He remarked, however, that it is by no means necessary that each of the small spheres, formed as crystallisation commences, should give rise to a separate crystal: the small spheres tend to coagulate, forming first rows and then groups of other and more complicated shapes, until the crystal is ultimately formed. To the intermediate bodies he gives the name of crystallites .