Root-Mean-Square Amplitude of Zero-Point Vibrations in a Crystal

Russian Physics Journal - The paper shows that the values of zero-point energy and vibrations of atoms in a crystal determined by the uncertainty principle, depend on the dynamic response of atoms....     

Ionization of solvent molecules by the field evaporation of ions from glycerol and ethylene glycol solutions

Using an electromembrane source, mass-spectrometric investigations into the field evaporation of ions from KI solutions in a water-glycerol mixture and in ethylene glycol are performed. The concentration of negatively charged solvent ions (deprotonated molecules) on the emitting surface of the liquid is determined. It is shown that, under the conditions of intense field evaporation of ions, the surface concentration of deprotonated glycerol and ethylene glycol molecules is several orders of magnitude higher than their equilibrium concentration in the absence of an electric field. The high concentration of solvent ions is associated with an increase in the autoprotolysis constant in a strong electric field.     

Isotope effect in the hydrogen distribution in the solid solution TiN<Subscript>0.40</Subscript>H<Subscript>0.19</Subscript>D<Subscript>0.19</Subscript>

The structure of a solid solution with a combined isotope composition based on TiN_0.40H_0.19D_0.19 (space group \(P\overline 3 m1\)) has been studied by neutron diffraction. The isotope effect in the distribution of H and D isotopes has been found: the isotopes are located in tetrahedral interstices of the same type but with different z coordinates; there is splitting of 2d tetrahedral interstices into two groups, the protium (H) and deuterium (D). Therefore, in the ordered “layered” structure of the TiN_0.40H_0.19D_0.19 solid solution, two different isotopes of the same element cannot be located at the same plane perpendicular to the threefold axis. The crystal-chemical analysis of the surroundings of H and D has been performed, and considerable differences have been revealed between the coordination polyhedra surrounding different hydrogen isotopes. It has been found that, in some metal-hydrogen systems, protium and deuterium should be treated as independent chemical components.     

Modification of cellulose in the solution of methanesulfonic acid

Russian Chemical Bulletin - Chemical modification of cellulose in solutions of methanesulfonic acid (MSA) is studied. It was found using IR spectroscopy, capillary electrophoresis, and scanning...     

Neutron diffraction study of dehydrogenation of titanium carbohydrides TiC<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>H<Subscript><Emphasis Type="Italic">y</Emphasis></Subscript>

The possibility of the synthesis of hydrogen-nonstoichiometric cubic titanium carbide ТiС _х of high purity from powdery nonstoichiometric cubic titanium carbohydride ТiС _х H _y or nonstoichiometric titanium carbide with admixture hydrogen by annealing in a continuously maintained vacuum of no worse than 1.33 × 10^–3 Pa at temperatures of 600–750°C for several hours has been shown. Similar annealing at higher temperatures (T ≥ 800°C) does not lead to the complete removal of hydrogen from a sample due to intensive sintering. In this case, it seems that pores between sintered particles are hydrogen traps, and the release of hydrogen through the surface of sintered particles is hindered.     

Extraction of Ions from a Polar Solution Using a Surface-Modified Membrane Interface

Technical Physics - Field-induced extraction of ions from a polar solution is implemented with the aid of an interface that represents a polymer track membrane with a conducting coating. A...     

Neutron diffraction study of the formation of ordered antiphase domains in cubic titanium carbide TiC0.60

A series of superstructural reflections (described within the sp. gr. Fd3m) are found to be split into three symmetric parts in the neutron powder diffraction pattern of titanium carbide TiC_0.60 annealed at a temperature of 600°C. No splitting of superstructural reflections is observed in the neutron diffraction pattern of TiC_0.60 annealed at relatively high temperatures (780°C). This phenomenon can be explained by that fact that the ordering of carbon atoms at relatively high temperatures (780°C) is accompanied by the formation of randomly oriented rather large antiphase domains (APDs) (450 Å). At relatively low temperatures (600°C), stacking faults arise in the arrangement of partially ordered carbon atoms. In this case, relatively small ordered APDs (290 Å) are formed, along with disordered ones.