Modification of Zinc-Implanted Silicon by Swift Xenon Ion Irradiation

50 keV ⁶⁴Zn⁺ ions to a dose of 5 × 10¹⁶ cm^–2 are implanted into substrates of single-crystal n-type silicon. Then the samples are irradiated at room temperature with 167 MeV ¹³²Xe²⁶⁺ ions with a fluence ranging from 1 ×10¹² up to 5 × 10¹⁴ cm^–2. Changes in the structure and properties on the sample surface and in its body are studied by scanning electron microscopy, energy dispersive microanalysis, atomic force microscopy, time-of-flight secondary ion mass spectrometry, and photoluminescence.     

Analysis of the Local Atomic Structure of the MIL-88а Metal–Organic Framework by Computer Simulation Using XANES Data

Experimental X-ray absorption spectra near the Fe K edge for as-synthesized MIL-88а metal–organic framework (MIL stands for Materials Institute Lavoisier) before and after activation have been obtained and analyzed for the first time. The theoretical analysis of experimental spectra has revealed changes in the local atomic structure of iron at the desorption of water from pores of the studied material in the process of activation.     

Cs/GaAs(100) surface: Two-dimensional metal or Hubbard insulator?

The evolution of the characteristic electron energy loss spectra accompanying the deposition of cesium on GaAs(100) surfaces with various superstructural reconstructions is studied experimentally. It is shown that the appearance of loss peaks in the GaAs band gap for Cs coverages θ_Cs>0.5 monolayers is due to resonances in the longitudinal and transverse polarizability of two-dimensional metallic clusters of adatoms. Pis’ma Zh. éksp. Teor. Fiz. 70, No. 8, 537–542 (25 October 1999)     

A Magnetoelastic Field in a Ferromagnetic Medium with a Spherical Cavity

The problem on the stress–strain state of an infinite isotropic body made of a magnetically soft material and containing a spherical cavity is considered. It is assumed that the body is under an external magnetic field. The basic characteristics of the stress–strain state and the magnetic field induced are determined and their singularities near the cavity are studied. Graphs are presented for the total magnitoelastic and Maxwell stresses as functions of the magnetic induction, the angle of dip, and the mechanical and magnetic properties of the material     

Gas hydrates and tetrahedrally coordinated structures determined by constructions of algebraic geometry

Graphs of 20-vertex polyhedra-cavities in gas hydrates and particular high-symmetry clusters of tetrahedrally coordinated structures are determined as incidence graphs of Desargues subconfigurations 10₃, 10 ₃ ³ , and 10 ₃ ⁴ . It is shown that symmetrically possible mutual transformations of rods of gas hydrates and tetrahedrally coordinated diamond-like structures correspond to conjugate subconfigurations of these configurations. It is established that the relations obtained determine on the symmetry level the mechanisms of incorporation of guest molecules into polyhedra-cavities of gas hydrates and their escape from these cavities. The corresponding structural models of mutual transformations of gas hydrates and tetrahedrally coordinated structures are implemented by the transfer of a minimum number of hydrogen bonds.     

Study of the Gilding Technology of the “Idol” from the 10th Century Mound “Chernaya Mogila” (“Black Grave”)

Crystallography Reports - A unique artifact—the “idol” from the 10th century mound “Chernaya Mogila” (“Black Grave”), a famous Old Rus’ site, has...     

Phosphorescence Peculiarities and Structure of Glassy Benzophenone

Journal of Applied Spectroscopy - Results of a comparative analysis of spectral-luminescent properties of crystalline and glassy benzophenone are presented. The main spectral characteristics...     

Changes in the Structure and Properties of Quartz Successively Implanted by Zn and F Ions during Thermal Annealing

Crystallography Reports - The temperature dependences of structural and phase transformations in quartz successively implanted by zinc and fluorine during annealing in nitrogen have been studied....     

Reconstruction of the Radiation Source Spatial Distribution in a Proportional Scattering Medium

Technical Physics - A new method of image reconstruction for single-photon emission computer tomography (SPECT) in a proportional scattering medium has been suggested. Detector counts have been...