Inorganics

Oxygen interstitial and vacancy conduction in symmetric Ln2 ± xZr2 ± xO7 ± x/2
We have compared (Ln2 − xZrx)Zr2O7 + x/2 (Ln = Nd, Sm) pyrochlore-like solid solutions with interstitial oxide ion conduction and Ln2(Zr2 − xLnx)O7 − δ (Ln = Nd, Sm) pyrochlore-like solid solutions with vacancy-mediated oxide ion conduction in the symmetric systems Nd2O3-ZrO2 (NdZrO) and Sm2O3-ZrO2 (SmZrO). We have studied their structure, microstructure, and transport properties and det...


New medium-temperature proton electrolytes based on CsH2PO4 and silicophosphate matrices
Silicophosphate gels ranging widely in P2O5 content and specific surface area have been synthesized by a sol-gel process. We have demonstrated the possibility of producing medium-temperature high-conductivity systems based on silicophosphate matrices and CsH2PO4. The thermal, structural, and transport properties of composite proton electrolytes have been investigated. The results indicate that ...
Ion-exchange iron sorption by carbon nanotubes and nanofibers
We have studied room-temperature equilibrium in systems containing an aqueous Fe(II) or Fe(III) salt solution and carbon nanofibers or carbon nanotubes with various contents of functional groups. The sorption capacity of the sorbents has been determined as a function of contact time, sorbent weight to solution volume ratio, salt concentrations in solution, solution pH, and sorbent “solubility...


Lithium ion conductivity and mobility in the Li0.12Na0.88Ta0.4Nb0.6O3 solid solution
Lithium ion mobility and the superionic phase transition in the Li0.12Na0.88Ta0.4Nb0.6O3 solid solution have been studied using temperature-dependent ionic conductivity measurements and Raman spectroscopy. From the temperature dependences of the conductivity and the width of a Raman line corresponding to Li+ and Na+ vibrations in the AOx (A = Na+, Li+) polyhedra, the average lifetime of the Li+...
Conversion of short-wavelength electromagnetic radiation in SiO2 opal photonic crystals
Reflection spectra of the (111) growth surface of opal photonic crystals differing in silica sphere diameter have been measured under illumination with narrowband ultraviolet and violet light from a laser and light-emitting diodes and with broadband light from a halogen lamp. We have found narrow strong bands differing in spectral position from the light from the short-wavelength excitation sou...


Phase states of Na/W/Mn/SiO2 composites at temperatures of catalytic oxidative coupling of methane
This paper analyzes phase states in the Na2O-WO3-MnO-Mn2O3 and Na2O-WO3-Mn2O3-SiO2 systems at temperatures of oxidative coupling of methane (OCM). The results indicate that, in the case of effective OCM, Na/W/Mn/SiO2 composite catalysts are in melt-Mn2O3 -tridymite (cristobalite) equilibrium....
Phase equilibria in the pseudoternary system Ag2Se-Ag8GeSe6-Ag8SnSe6
Phase equilibria in the Ag2Se-Ag8GeSe6-Ag8SnSe6 system have been studied by differential thermal analysis, X-ray diffraction, scanning electron microscopy, and emf measurements on concentration cells with Ag4RbI5 as a solid electrolyte. We have mapped out the T-x phase diagram of the constituent binary system Ag8GeSe6-Ag8SnSe6, those of two mutually perpendicular sections, and the liquidus proj...

Effect of the composition of starting yttrium aluminum hydroxide sols on the properties of yttrium aluminum garnet powders
A technique has been developed for the synthesis of yttrium aluminum garnet sols aggregationstable in water as a dispersion medium. Depending on the type of precursor used, the temperature of yttrium aluminum garnet formation varies from 900°C to 1100°C. We have obtained yttrium aluminum garnet nanopowders with an average particle size from 40 to 300 nm, depending on the aluminum yttrium hydr...
Reflection spectra of synthetic opal at liquid-nitrogen temperature
Reflection spectra of the (111) surface of synthetic opal crystals with sphere diameters of 210, 250, and 300 nm have been measured at room and liquid-nitrogen temperatures. At cryogenic temperatures, we observed a narrowing and shift of photonic band gaps due to liquid nitrogen infiltration into the opal pores. We have calculated ω(k) dispersion relations and determined the reflectivity of th...

Composition and predominant electron scattering mechanisms in Hg1 − x− yCdxEu
The surface of Hg1 − x− yCdxEuySe crystals has been examined by electron microscopy using backscattered and secondary electron imaging, and the composition of the crystals has been determined. Using transport and optical measurements, we have identified the predominant electron scattering mechanisms in the Hg1 − x− yCdxEuySe crystals....
Preparation of Ln2O2S (Ln = Gd, Dy, Y, Er, Lu) in flowing hydrogen and hydrogen sulfide
The exposure of anhydrous Ln2(SO4)3 (Ln = Gd, Dy, Y, Er, Lu) sulfates to flowing hydrogen in the range 500–1050°C leads to the formation of Ln2O2S + Ln2O3 materials. With increasing reaction temperature, the mole fraction of Ln2O2S in the samples decreases. Single-phase Ln2O2S (Ln = Gd, Dy, Y, Er, Lu) compounds have been obtained by exposing the rare-earth sulfates first to flowing hydrogen ...

Phase equilibria and electrical properties of barium-containing relaxor-based solid solutions
We have studied the effect of modification with Ba on the phase composition, structure, and electrical properties of ceramic samples of Pb(1−x)Bax(Mg1/3Nb2/3)m(Zn1/3Nb2/3)y(Ni1/3Nb2/3)nTizO3 (0 ≤ x≤ 0.15) solid solutions and investigated phase equilibria in this system in the range 0 ≤ x≤ 0.15. The results indicate that a tetragonal and a low-symmetry phase coexist in the composition ...
Electrochemical, optical, and magnetic properties of NixInSe (0 < x≤ 1) intercalation compounds
We have studied the electrochemical, optical, and magnetic properties of nickel-intercalated InSe single crystals. The energy position of the excitonic maximum and the full width at half maximum of the excitonic band in the NixInSe intercalation compounds have been shown to be nonmonotonic functions of nickel concentration. Nickel-intercalated InSe possesses ferromagnetic properties: the depend...
Electrical conductivity and structural properties of proton electrolytes based on CsH2PO4 and silicophosphate matrices with low phosphorus content
We have demonstrated that silicophosphate matrices with various P2O5 contents can be used to produce medium-temperature highly conductive CsH2PO4-based composites. The low-temperature conductivity of all the composites studied is higher than that of the salt at low humidity by up to three and half to four orders of magnitude. The phase transition disappears with increasing additive content. The...
Lanthanum oxide sulfurization in ammonium rhodanide vapor
We have studied phase formation processes in the La-O-S system during La2O3 sulfurization in ammonium rhodanide vapor and identified the sequence of steps in lanthanum oxide conversion into oxysulfides and lanthanum sulfide using X-ray diffraction, IR absorption spectroscopy, and Raman spectroscopy. In the initial stage of the sulfurization process, we observed the formation of lanthanum dioxyd...