Transverse Thermomagnetic Effect in the Two-Dimensional Electron Gas of Surface Semiconductor Superlattice

Journal of Experimental and Theoretical Physics - The surface current density of charge carriers in two-dimensional doubly periodic n-type semiconductor superlattices in an external magnetic field...     

Giant magnetoresistance of iron-chromium superlattices at microwaves

Interaction between an rf electromagnetic field and the Fe/Cr superlattice placed in a rectangular waveguide so that a high-frequency current passes in the plane of superlattice layers is considered. The transmission coefficient versus the magnetic field strength is found at centimeter waves, and a correlation between this dependence and the field dependence of the dc magnetoresistance is established. It is shown that a change in the transmission coefficient may greatly exceed the giant magnetoresistance of the superlattice. The frequency dependence of the microwave measurements has an oscillatory character. The oscillation frequencies are analyzed in terms of wavelet transformation. Two types of oscillation periods are found to exist, one of which corresponds to the resonance of waves traveling in the superlattice along the direction parallel to the narrow wall of the waveguide.     

Reaction of D2 with palladium fulleride C60Pd4.9

Fullerene deuteride was obtained by the reaction of deuterium with solid palladium fulleride C₆₀Pd_4.9 under fairly mild conditions. The compound was identified by FD-MS, UV-Vis and IR spectroscopies, and TLC.Translated from Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 483–484, February, 1996     

Study of an iron/ruthenium catalyst by XPS

Analysis of the surface composition of a Fe/Ru catalyst containing 40 wt.% of RuO₂ in bulk Fe₂O₃ has been carried out by XPS. It has been shown that after reduction the catalyst surface is enriched with iron.     

Identification of impurities accumulated in the extractant in the course of purification of wet-process phosphoric acid with tri-<Emphasis Type="Italic">n</Emphasis>-butyl phosphate

Impurities accumulated in the extractant in the course of operation of the plant for purification of wet-process phosphoric acid, obtained from apatite concentrate, by extraction with tri-n-butyl phosphate are identified by IR and mass spectra.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 9, 2004, pp. 1425–1429.Original Russian Text Copyright © 2004 by Lembrikov, Konyakhina, Volkova, Perov, Kiseleva, Ershova.     

Change in the structure of oriented poly(vinyl alcohol) fibers impregnated with potassium bisulfate during heat treatment in air

The structural transformations of oriented PVA fibers impregnated with potassium bisulfate during their heat treatment in air to a temperature of 600°C were studied. The preliminary thermal stabilization of the impregnated fibers was conducted in air at 215°C for 1 h with maintenance of a high degree of orientation of the fibers. The melting peak of the preliminarily thermally stabilized impregnated PVA fibers is completely suppressed during their subsequent heat treatment in air, and the yields of coke residue are 48 and 43% of the thermally stabilized fiber mass at 500 and 600°C, respectively.     

Quasi-diamagnetism and exchange anisotropy in Ni-Mn-In-Co Heusler alloys

The quasi-diamagnetism effect that manifests itself in the negative magnetic susceptibility observed in weak magnetic fields during cooling of samples below some critical temperature has been revealed in Ni₄₈Co₂Mn₃₅In₁₅ Heusler alloys. The effect has been attributed to a strong nonequilibrium of the system due to the presence of magnetic and structural disorders and exchange anisotropy.     

Valence state of elements on the Fe—Ru catalyst surface treated in various media

X-ray photoelectron spectroscopy (XPS) is used to show that Fe and Ru on the catalyst surface virtually completely transform into the metallic state during the reduction of the Fe-Ru catalyst. Analysis of the spectra of nitrogen, which is present in the reduced and activated Fe-Ru catalyst, showed the presence of three Nls signals with the binding energies 400.4, 398.6, and 397.4 eV. These bands are assigned to three nitrogen states: NH₃, NH and/or NH₂, and N₂ (or one of the forms of molecular nitrogen, which is a precursor of dissociation), respectively