Structure and Reactivity of Arsazocompounds in Comparison with Phosphorus Analogs

Abstract

A suitable effective method of arwocompounds 2 synthesis through the alkoxyarsoranes I has been suggested. In dependence on the nature of substituents R and R arsazocompounds (as their phosphorus analogs) may exist in monomeric (2) and dimeric (3) forms, that has been confirmed by X-ray analysis.     

Synthesis of New SrPb3Br8 Crystals and Investigation of Their Properties

Crystallography Reports - A new compound, SrPb3Br8, has been synthesized and investigated by X-ray diffraction and spectroscopic methods. Its crystal structure is described as follows: Pnma, a =...     

A multiple production study of neutral strange particles in νμ CC interactions in the NOMAD experiment

A multiple production study of neutral strange particles in ν_μ charged current interactions has been performed using the full data sample from the NOMAD experiment. This analysis allows one to investigate the mechanisms of strange particle production in neutrino interactions. In this study we have tried to build a model for the production of strange particles, which would allow us to describe our measured rates of neutral strange particles, as well as the rates of the single-, double-and triple-V ⁰ production: Λ, K ⁰, , K ⁰ K ⁰, ΛK ⁰, Λ , K ⁰ , ΛΛ, and K ⁰ K ⁰ K ⁰. The text was submitted by the authors in English.     

The Influence of Film Thickness on Annealing-Induced Grain Growth in Pt Films

Technical Physics - Pt films with thickness h = 20–100 nm deposited on oxidized с-Si(100) substrate have been subjected to vacuum annealing at 500°C for 1 h, which resulted in...     

Effect of Cyclic Hydrocarbon Vapors on the Structure of YBa2Cu3Oy

Russian Journal of Physical Chemistry A - The effect vapors of the simplest cyclic hydrocarbons have on the structure of YBa2Cu3Oy (123) with high (у = 6.96) and low (у = 6.3) oxygen...     

Paramagnetism in copper monoxide systems

This paper describes the problem of high-temperature superconductivity related to investigations of the magnetic susceptibility, electron paramagnetic resonance, and O Kα x-ray emission spectra of samples from the following systems based on copper monoxide: CuO-Cu, CuO-Cu₂O and CuO-MgO. In all these systems, thermal processing results in a paramagnetism which is not observed in the individual components of these systems before they are processed. O Kα spectra of the interface of a Cu-single-crystal CuO film structure indicate the presence of not only Cu²⁺ but also Cu¹⁺ ions in the layer of CuO in close contact with Cu. Possible reasons for the appearance of paramagnetism in these systems are discussed. It is proposed that a paramagnetic layer at the contact between the antiferromagnetic copper monoxide and the other copper-oxide phases or with copper could be the cause of the impurity metastability observed previously in the high-T _c superconducting phase. Fiz. Tverd. Tela (St. Petersburg) 40, 295–298 (February 1998)     

Magnetoresistive properties of nanostructured magnetic metals,manganites, and magnetic semiconductors

We consider methods for controlling magnetoresistive parameters of magnetic metal superlattices, manganites, and magnetic semiconductors. By reducing the thickness of ferromagnetic layers in superlattices (e.g., Fe layers in Fe/Cr superlattices), it is possible to form superparamagnetic clustered–layered nanostructures with a magnetoresistance weakly depending on the direction of the external magnetic field, which is very important for applications of such type of materials. Producing Mn vacancies and additionally annealing lanthanum manganites in the oxygen atmosphere, it is possible to increase their magnetoresistance by more than four orders of magnitude. By changing the thickness of p–n junction in the structure of ferromagnetic semiconductors, their magnetoresistance can be increased by 2–3 orders of magnitude.     

Crystal structure of [Co(NH3)5NO2]C2O4. Analysis of specific contacts and structural effects hindering inner-spheric nitro-nitrito isomerization

The structure of [Co(NH₃)₅NO₂]C₂O₄ is solved and refined (space group Immm, a=7.428(2), b=9.790(3), c=6.568(1) Å, V=477.6(2) ų, Z=2; R₁=0.0177, wR₂=0.0279 for F²>4σ(F²); R₁=0.1177, wR₂=0.0643 for all data; residual electron density from 0.125 to ?0.140 e/ų). Specific contacts in the structure are analyzed. Crystal chemical interpretation is suggested to explain the occurrence of photodecomposition rather than photochemical bond isomerization under the action of light in cobalt(III) nitropentammoniate oxalate crystals, in contrast to all previously investigated cobalt(III) nitropentammoniates.