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Three types of solid solutions of new nickel–cobalt–manganese spinels were synthesized by substitution for manganese cations in oxide Mn3O4: Ni(1 – x)Mn(2 + x)O4, Ni(1 – x)Co(1 – x)Mn(1 + 2x)O4, and Ni(1 – 2x)Co(0.5 – x)Mn(1.5 + 3x)О4. Complex oxides have been produced by solution combustion synthesis. The produced spinels expand the range of materials suitable for using as anodes of lithium-ion batteries.

Парфент ьев Николай Павлович, заведующий кафедрой теологии, культуры и искусства, доктор исторических наук, доктор искусствоведения, профессор, заслуженный деятель науки Российской Федерации. Южно-Уральский государственный университет (г. Челябинск). E-mail: parfentevnp@susu.ru Шерстобитова Екатерина Сергеевна, искусствовед, аспирант кафедры теологии, культуры и искусства, Южно-Уральский государственный университет (г. Челябинск). E-mail: еkaterina.sherstobitowa@yandex.ru N. P. Parfentiev, parfentevnp@susu.ru E. S. Sherstobitova, ekaterina.sherstobitowa@yandex.ru South Ural State University, Chelyabinsk, Russian Federation

Парфентьев николай Павлович, заведующий кафедрой теологии, культуры и искусства, доктор исторических наук, доктор искусствоведения, профессор, заслуженный деятель науки Российской Федерации. Южно-Уральский государственный университет (г. Челябинск, Россия). E-mail: parfentevnp@susu.ru Шерстобитова екатерина сергеевна, искусствовед, аспирант кафедры теологии, культуры и искусства, Южно-Уральский государственный университет (г. Челябинск, Россия). E-mail: еkaterina.sherstobitowa@yandex.ru N. P. Parfentiev, parfentevnp@susu.ru E. S. Sherstobitova, ekaterina.sherstobitowa@yandex.ru South Ural State University, Chelyabinsk, Russian Federation

Co-doped TiO2 is one of the most extensively studied oxides for applying as dilute magnetic semiconductors due to its room temperature magnetism. Here we present results of the studies of Ti0.97Co0.03O2 nanopowders synthesized by hydrothermal method by means of X-ray diffraction, soft X-ray absorption spectroscopy (Ti L2,3 and Co L2,3 spectra), hard X-ray absorption spectroscopy (Co K spectra), and 1s3p resonant inelastic X-ray scattering at the Co K edge. According to X-ray diffraction data and Ti L2,3 X-ray absorption spectra, all the samples before the thermal treatment exhibit anatase structure with substantial amount of amorphous phase. After annealing the Ti0.97Co0.03O2 samples in vacuum or hydrogen at 700oC, the anatase structure persists while amorphous phase contribution is eliminated. Surface sensitive soft X-ray absorption Co L2,3 spectroscopy revealed only Co2+ ions tetrahedrally coordinated by oxygen ions and no sign of metallic Co. Co2+ tetrahedral sites (instead of typical octahedral ones) ...

The influence of the cerium oxide concentration on the properties of glasses and glass ceramics of the SiO2–Al2O3–CaO–Na2O–MgO–K2O–B2O3–CeO2 system as potential adhesive and sealing materials for solid oxide fuel cells was studied. According to the data of differential scanning calorimetry, variation of the CeO2 concentration does not appreciably influence the glass transition and crystallization temperatures of glasses. As the cerium oxide concentration is increased, the linear thermal expansion coefficient increases for the glasses but decreases for the partially crystalline samples. The gluing temperature of the glass sealants prepared allows their use for joining YSZ solid electrolytes with interconnectors of Crofer22APU type in solid oxide fuel cells..

The structure of dry and hydrated perovskite La 0.9 Sr 0.1 ScO 3 − δ has been studied by means of X-ray and neutron powder diffraction methods. Preferable positions for oxygen vacancies and deuterons in the oxide have been determined. Thermodynamics of water vapour uptake and transport phenomena have been experimentally investigated at p H 2 O = 0.24 atm and p O 2 = 0.18 atm in the temperature range from 300 to 950 °С. The enthalpy and entropy of hydration reaction have been calculated. The oxidation enthalpy for two possible mechanisms of hole transfer (band conduction and small polaron hopping) have been estimated. The electrical conductivity has been investigated by means of impedance spectroscopy measurements in the temperature range from 500 to 900 °С and at the oxygen partial pressures of 10 − 20 atm p O 2 0.9 Sr 0.1 ScO 3 − δ oxide was found to be a pure protonic conductor at temperatures below 600 °С under reducing conditions.

The charge states of the cobalt ions in TiO2 nanopowders with the anatase lattice are studied by soft X-ray absorption spectroscopy. It is found that, at a low cobalt impurity concentration (1.8 at %), the cobalt ions with an oxidation state 2+ are mainly located in the tetrahedral (T d ) environment of oxygen ions. Amorphous titanium dioxide exists on the sample surface before heat treatment. Annealing in vacuum or hydrogen leads to the enrichment of the nanoparticle surfaces with Co2+ ions, a change in the coordination of the remaining part of cobalt ions from octahedral to tetrahedral, stabilization of the anatase structure, and the disappearance of the amorphous phase. The crystal lattice of the samples with a relatively high cobalt concentration (12 at %) is distorted, and annealing does not cause the disappearance of the amorphous phase of TiO2. Cobalt is reduced to its metallic state upon hydrogen annealing of the samples with a high cobalt concentration.

Poly(nitriles) are among the polymer matrices providing high salt solubility and, in some cases, superionic lithium conductivity at ambient temperatures observed in highly concentrated solvent-free polymer electrolytes. However, the properties of these electrolytes in which ionic aggregation prevails remain difficult to reproduce and predict, as current theories do not adequately model their attributes. The development of new concepts for ion transport in highly concentrated solid polymer electrolytes (SPEs) requires a better understanding of the fundamentals of structure formation in a polymer–salt system over a wide concentration range including salt precipitation. In an attempt to approach this goal, a series of fundamental studies was carried out on the systems based on a rubbery random copolymer of butadiene and acrylonitrile (abbreviated as PBAN). In the present work, LiBr with monatomic halide anion was used as a lithium salt. The effect of LiBr concentration (0.05 to 3.35 mol kg−1) on phase composition, ion–molecular interactions, glass transition temperature, and ionic conductivity was studied by optical microscopy, FTIR, X-ray diffraction, DSC, and impedance measurements. The results were compared with those of PBAN–LiClO4 and PBAN–LiAsF6 studied previously. Low salt solubility and separation of a metastable cubic CsCl-type polymorph of LiBr were established. The highest conductivity of ∼10−4 S cm−1 at >50 °C was observed for heterogeneous samples comprising this phase. While the conductivity of PBAN–LiBr was lower than that of PBAN–LiClO4 and PBAN–LiAsF6, this study provides a new insight into the nature of polymer electrolyte systems.

We present a study of the crystal structure, ionic conductivity and Li migration map in a wide temperature range for the Li2ZrO3 and Li1.8ZrO3-δ samples synthesized by the solid state reaction and soft chemistry methods, respectively. Both samples were found to be Li-deficient at room temperature with the partially vacant Li[1] sites. Thermally activated redistribution of Li+ ions between two lithium sites has been revealed by high temperature neutron diffraction. The redistribution of lithium results in rise of the ionic conductivity and drop of the activation energy observed on the AC conductivity data at the temperatures above 740 K for Li2ZrO3 and 710 K for Li1.8ZrO3-δ. It has been found that more deficient Li1.8ZrO3-δ sample prepared by the soft chemistry method exhibits enhanced ionic conductivity. Three-dimensional lithium migration map composed of the stripe-like migration pathways has been constructed. Most of the elementary channels composing lithium migration map were found to be probabilistic ones, which indicates bottle-necked ionic transport in both compounds.

The electrical conductivity of lithium diphosphate Li 4 P 2 O 7 has been measured and jump-like increasing of ionic conductivity at 913 K has been found. The crystal structure of Li 4 P 2 O 7 has been refined using high temperature neutron diffraction at 300–1050 K. At 913 K low temperature triclinic form of Li 4 P 2 O 7 transforms into high temperature monoclinic one, space group P 2 1 / n , a =8.8261(4) A, b =5.2028(4) A, c =13.3119(2) A, β =104.372(6)°. The migration maps of Li + cations based on experimental data implemented into program package TOPOS have been explored. It was found that lithium cations in both low- and high temperature forms of Li 4 P 2 O 7 migrate in three dimensions. Cross sections of the migrations channels extend as the temperature rises, but at the phase transition point have a sharp growth showing a strong “crystal structure – ion conductivity” correlation.

The TbNi5 compound shows an interesting magnetic phase transition with an incommensurate structure below 23 K, whose true nature remains unresolved. In order to solve this question, we have carried out polarized neutron diffraction experiments by measuring temperature and field dependence of the intensities of satellites and Bragg reflections. From the temperature dependence of both satellite peaks and Bragg reflection, we demonstrated that it has only one magnetic structure at a given temperature. Furthermore, unlike previous reports, we found that both ferromagnetic and modulated components of the Tb ion magnetic moments should be collinear to each other. Our data also show strong depolarisation effects that are most likely to arise from domain structure of ferromagnetic component. A critical field, which destroyers a modulated magnetic structure is found to be lower than a field value to saturate the ferromagnetic component, in which the intensity of Bragg ferromagnetic reflections reaches saturation.

Neutron-diffraction studies of a single crystal of TbNi5 have been performed. Temperature and field dependences of the intensities of the Bragg reflection (001) and magnetic satellites (001)− and (001)+ have been determined. In the temperature range of 7–10 K, sharp changes in the intensities of both the Bragg reflection and its satellites have been revealed. A conclusion is made that these changes are due to the existence of a magnetic transition from an incommensurate into a lock-in structure. It has been found that at 11 K an external magnetic field μ0H = 0.1 T oriented along the [100] axis induces the same magnetic state of the crystal as its cooling to 7 K in the absence of a field. In an external magnetic field μ0H = 0.4 T, there occurs a magnetic transition from the incommensurate phase with a wave vector k = 2π/c (0, 0, 0.18) into a commensurate ferromagnetic phase with k = 0. In the ferromagnetic phase, an increase in the field from 0.4 to 0.6 T is accompanied by an increase in the intensity of the ferromagnetic reflection (001) by a factor of 1.6. This indicates the existence of strong fluctuations of the magnetization at 0.4 T.

Temperature dependent micro-structural and magnetic properties of CrO2 nanorods have been studied by neutron diffraction from 3.5 K to 450 K. Rietveld analysis considering the anisotropic shape of nanorods suggested that each CrO2 nanorod probably consisted of a few microscopically oriented grains. Around the ferromagnetic transition temperature (∼395K), a dominant lattice distortion in the tetragonal phase was not a change along the c axis, but a contraction along the ab axes perpendicular to the lengthwise direction of the nanorods, which was caused by an apical bond contraction in CrO6 octahedra. The obtained structural and magnetic data of CrO2 nanorods were compared with the temperature dependent resistivity of the epitaxial CrO2/TiO2 film, and strong couplings between structural, magnetic, and electric properties in the half-metallic ferromagnet CrO2 were observed.

The Tb0.1Tm0.9Co2 compound is investigated using neutron diffraction. It is shown that this compound undergoes an irreversible band metamagnetic transition induced by an external magnetic field. The magnetization of the Co sublattice increases from 0.2 to 0.6 μB. The critical field strength is approximately equal to 1 T at temperatures of 1.8 and 4.0 K. As the temperature increases, the effect of the magnetic field on the magnetic state of the sample weakens and, at 25 K, no noticeable changes are observed in an external field of 0.75 T. The metamagnetic transition at 1.8 K is accompanied by the disappearance of rhombohedral distortions and brings about a lattice expansion by approximately 1%.

The electric resistivity and neutron diffraction measurements of the intermetallic compounds Nd{sub 1-x}Tb{sub x}Co{sub 2} (x = 0, 0.2, 0.3, 0.5, 0.7, or 1) have been performed. All compounds have a cubic structure at room temperature and a rhombohedral structure at 4.2 K. The magnetic structure of these compounds is described by the wave vector k = 0. The magnetizations of the rare earth and cobalt sublattices increase with increasing x. The concentration dependence of the cobalt sublattice magnetization is explained on the basis of the model of metamagnetic band subsystem in compounds of the RCo{sub 2} type.

A comparative study of four series of pyrrhotite-type chalcogenide compounds Fe(7-y)M(y)X(8) (X = S, Se) with substitution of Ti or Co for iron has been performed by means of x-ray and neutron powder diffraction, and by magnetization measurements. In Fe(7-y)M(y)X(8) compounds having a ferrimagnetic order at y = 0, the substitution of either Ti or Co for iron is observed to result in a monotonous decrease of the magnetic ordering temperature, while the resultant magnetization shows a non-monotonous behavior with a minimum around y = 1.0-1.5 in all the Fe(7-y)M(y)X(8) families except Fe(7-y)Co(y)Se(8). Suppression of a magnetically ordered state with substitutions in Fe(7-y)M(y)X(8) is ascribed to nearly zero values of Ti and Co magnetic moments, while the non-monotonous changes of the resultant magnetization are explained by the compensation of the sublattice magnetizations due to the non-random substitutions in alternating metallic layers. The difference in the cation partitioning observed in Fe(7-y)Ti(y)X(8) and Fe(7-y)Co(y)X(8) is attributed to the difference in the spatial extension of Ti and Co 3d orbitals. High coercive field values (20-24 kOe) observed at low temperatures in the Ti-containing compounds Fe(7-y)Ti(y)X(8) with y ⩾ 3 are suggested to result from the enhancement of Fe orbital moment due to the Ti for Fe substitution.

The Tm1−x TbxCo2 (0 ≤ x ≤ 1) system was studied by measuring the magnetic susceptibility, electrical resistance, and neutron diffraction. In the compounds with 0 < x ≤ 0.15, an inhomogeneous magnetic state characterized by the existence of large regions (up to 100 A in size) with short-range ferrimagnetic order was found to occur. The maximum of the residual electrical resistance observed in the compound with x = 0.1 at the magnetic ordering temperature was established to be due to the scattering of conduction electrons by localized spin fluctuations associated with f-d exchange fluctuations caused by the substitution of terbium for thulium. The increase in the terbium concentration to x ≥ 0.15 leads to a sharp increase in the Co sublattice magnetization and the establishment of a long-range ferromagnetic order, which indicates a concentration metamagnetic transition in the band subsystem.

The crystal structure of Li4P2O7 is refined by high temperature neutron diffraction at 300—1050 K.

AC- and DC-susceptibility, high-field magnetization and neutron diffraction measurements have been performed in order to study the magnetic state of R5Pd2 (R = Ho, Tb) compounds. The results show that both compounds undergo cluster-glass freezing upon cooling below Tf. According to the neutron diffraction a long-range magnetic order is absent down to 2 K and magnetic clusters with short-range incommensurate antiferromagnetic correlations exist not only below Tf but also in a wide temperature range above the freezing temperature (at least up to 2Tf). A complex cluster-glass magnetic state existing in Ho5Pd2 and Tb5Pd2 down to low temperatures results in rather complicated magnetization behavior in DC and AC magnetic fields. Such an unusual magnetic state in compounds with a high rare-earth concentration may be associated with the layered type of their crystal structure and with substantial atomic disorder, which results in frustrations in the magnetic subsystem.

X-ray and neutron powder diffraction were employed to study the crystal and magnetic structures of pseudo-binary Laves-phase compounds (Zr 1− x Mn x )Co 2 and (Zr 1− x Mn x )Co 2.45 . It is found that the Zr 0.8 Mn 0.2 Co 2 compound has the MgCu 2 -type cubic structure (space group Fd3m), while Zr 0.64 Mn 0.36 Co 2.45 and Zr 0.64 Mn 0.36 Co 2 have the AuBe 5 -type (space group F-43m) cubic structure. All compounds are ferromagnets.

The crystal structure and magnetic properties of ErFe 2D 3.1 have been studied by means of magnetic measurements and neutron powder diffraction in a wide temperature range from the highest temperature T = 450 K down to the lowest one T = 12 K. The crystal structure of ErFe 2D 3.1 is found to be strongly modified by temperature: the high-temperature cubic structure decomposes to the deuterium-deficient cubic and deuterium-rich distorted phases which coexist in a wide temperature range below 400 K and exhibit successive structural transitions. The neutron powder diffraction patterns analysis revealed ordering of deuterium atoms over preferential A 2B 2 interstitial sites upon cooling. Below the Curie temperature ErFe 2D 3.1 is a ferrimagnet. Two separate magnetic ordering temperatures for Er and Fe magnetic sublattices were observed. A large magnetic anisotropy has been found in ErFe 2D 3.1 at low temperature. © 2012 Elsevier B.V. All rights reserved.

The structure of the title compounds is determined by X-ray and high-resolution neutron powder diffraction at 450 K.