Transformation of graphite islets on the surface of recrystallized platinum foil under the action of mechanical loading

The effect of uniaxial tension on the behavior of graphite segregates (islets) on the surface of recrystallized platinum foil is studied in situ by low-energy electron diffraction and Auger electron spectroscopy. Mechanical stresses are shown to have a significant influence on the size and orientation of the islets. The alignment of the islets along steps on the platinum surface is discovered.     

Microhardness anisotropy and the density of atoms in the unit identity volume of crystals

A new criterion of the reticular and polar anisotropy of microhardness is proposed: the density of atoms in the unit identity volume, i.e., the ratio of the number of atoms of one species in the atomic planes (plane) contained within the limits of the unit identity volume to the sum of the areas of these planes (plane) containing atoms of that species. It is shown that these densities of lanthanide, actinide, and boron atoms correlate satisfactorily with the reticular and polar microhardness anisotropy of their tetraborides and hexaborides. This criterion can be used to predict the nature of the variation of the reticular and polar microhardness anisotropy for other classes of compounds as well. Fiz. Tverd. Tela (St. Petersburg) 40, 481–486 (March 1998)     

Dependence of the atomic structure and surface relief of platinum foils on the annealing and rolling conditions

The effect of cold rolling, polishing, and thermal annealing conditions on the atomic structure and surface geometry of platinum foils has been studied. The surface morphology has been analyzed using low-energy electron diffraction, atomic force microscopy, and scanning tunneling microscopy. The chemical composition of the surface has been evaluated by Auger electron spectroscopy. It has been demonstrated that a variation in the conditions used for the preparation of the samples makes it possible to produce surfaces with different degrees of perfection from atomically smooth to rippled, fractal, and diffraction-disordered surfaces.     

The Influence of Mechanical Treatment on the Surface Relief of a Fe77Ni1Si9B13 Metal Glass

Physics of the Solid State - The micro- and nanoreliefs of the loaded surfaces of a Fe77Ni1Si9B13 metal glass are probed via scanning tunneling and atomic force microscopies, scanning electron...     

Structural changes on the surface of tungsten foils under uniaxial tension

A change in the surface morphology of recrystallized tungsten foil under the effect of uniaxial tension in ultrahigh vacuum is studied by low-energy electron diffraction and atomic force microscopy. It is found by using low-energy electron diffraction that on the foil surface consisting of separate blocks with dominant face (112), there is a turn in orientation of the structural blocks. The analysis of the topograms of different areas of the side surface of a broken sample, obtained by atomic force microscopy, enabled the association of changes in the atomic structure of the surface layers of foil with a change in its relief by mechanical action.     

Alteration of the lattice constant and the composition of KCl and KBr crystals under macrogravity

In KCl and KBr crystals grown from supersaturated aqueous solutions under centrifuging (3g, 7g, and 12g) the lattice constant and the halogen content are altered significantly in comparison with original compounds, and the microhardness is increased by 1.5–2 fold. Fiz. Tverd. Tela (St. Petersburg) 39, 1792–1793 (October 1997)     

Dynamics of the Surface Morphology of a Tungsten Foil under Load

Physics of the Solid State - The dynamics of changes in the surface morphology of recrystallized tungsten foil under the action of uniaxial tension was studied in situ by the methods of low-energy...     

Influence of low-temperature annealing on the morphology of the surface layer of an iron-based amorphous alloy

The influence of isothermal annealing on the chemical composition, microstructure, and surface relief of ribbons of an amorphous Fe₇₇NiSi₉B₁₃ alloy was studied using Auger electron spectroscopy and transmission electron, atomic-force, and scanning tunneling microscopy. It is established that an annealing below the glass transition temperature results in a boron enrichment of the ribbon surface layer on the side of the ribbon that was not in contact with the roller during quenching. On both sides of a ribbon, islands of crystallized material 2–5 μm in size appear consisting of nano-and microcrystals of α-Fe on the roller-contacting side and of iron boride on the opposite side. The surface relief on the roller-contacting side of a ribbon and that on the opposite side are shown to differ in terms of their spectral and fractal characteristics after annealing. The effect of the chemical composition and excess free volume of the surface layer on the formation of islands of crystallized material and surface relief is discussed.     

Parameters and properties of crystals of ionic compounds obtained by centrifugal separation of supersaturated aqueous solutions

The change in the chemical composition, structural parameters, and properties of Ba(NO₃)₂, PbCl₂, and KI crystals and the binary alkali-halide systems LiCl-KCl (eutectic) and LiCl-NaCl and KCl-KI (solid solutions) after centrifugal separation under acceleration (1.3, 6.2, 11.8)×10³ g is investigated. The composition variation was monitored by the methods of chemical gravimetric and titration analyses, as well as of flame-photometric and spectrophotometric analyses. Acceleration causes a change in the chemical composition, lattice parameter, refractive index, and microhardness in all systems as compared to the initial values. It is found that centrifugation affects the systems with different masses of cations more strongly than the systems with different masses of anions. A criterion of the ratio of the masses of ions (cations and anions) rat i/i is proposed for predicting the effect of centrifugation on the change in the chemical composition and properties of compounds and their systems (a larger value of this ratio leads to a stronger variation of the composition and properties). The crystals of all compounds and solid solutions display an increase in microinclusions (visible only in transmitted light) upon an increase in the acceleration. The lattice parameters and microhardness measured in KCl and KBr crystals four years after their fabrication by using centrifugal separation indicate a considerable return to their initial values.