Phase equilibria and thermodynamic properties of oxide systems on the basis of rare earth, alkaline earth and 3d-transition (Mn, Fe, Co) metals. A short overview of

Review is dedicated studies of phase equilibria in the systems based on rare earth elements and 3d transition metals. It’s highlighted several structural families of these compounds and is shown that many were found interesting properties for practical application, such as high conductivity up to the superconducting state, magnetic properties, catalytic activity of the processes of afterburning of exhaust gases, the high mobility in the oxygen sublattice and more

Phase equilibria, crystal structure and oxygen nonstoichiometry of the complex oxides in Sm – (Sr, Ba) – (Co, Fe) – O systems

Received: 18.01.2018. Accepted: 14.02.2018. Published: 10.05.2018.Present paper contains available information on the phase equilibria in the Sm – (Sr, Ba) – (Co, Fe) – O systems, including the synthesis routes used, crystal structure, which is often depended on oxygen nonstoichiometry, the data on thermodynamic stability of complex oxides, the obtained results on the homogeneity ranges of solid solutions, formed in the systems, and graphical presentation of phase relations in a form of phase diagrams

Crystal structure and properties of novel oxide Sm0.9Ca1.1Fe0.7Co0.3O4–δ

Received: 13.11.2018. Accepted: 05.12.2018. Published: 31.12.2018.Sm0.9Ca1.1Fe0.7Co0.3O4–δ oxide with the K2NiF4‑type structure was prepared using a glycerin-nitrate technique. The XRD pattern of Sm0.9Ca1.1Fe0.7Co0.3O4–δ was refined by the Rietveld method within an orthorhombic structure (space group Bmab). The electrical conductivity, Seebeck coefficient, and thermal expansion of Sm0.9Ca1.1Fe0.7Co0.3O4–δ were measured depending on temperature in air. The change of oxygen nonstoichiometry determined by TGA in air does not exceed 0.01. The oxygen content in Sm0.9Ca1.1Fe0.7Co0.3O4–δ determined by the reduction in a hydrogen flux is equal to 3.96 ± 0.01. The positive value of Seebeck coefficient indicates that the predominant charge carriers in the oxide studied are electron holes.This work was supported in parts by Act 211 Government of the Russian Federation, agreement 02.A03.21.0006

PHASE EQUILIBRIUM AND CRYSTAL STRUKTURE OF PEROVSKITE OXIDES IN THE SYSTEM Sm-Sr-Fe-Co-O

The samples Sr1-xSmxFe1-yCoyO3-δ were synthesized by solid-state and glycerin nitrate techniques. XRD patterns of the single phase samples were refined by Rietveld method within the cubic structure (Pm3m sp. gr.) or within the tetragonal structure (I4/mmm sp. gr.). It was found, that gradual substitution of strontium by samarium leads to the decrease of unit cell parameters and unit cell volume, that can be explained by the relative cation. The projections of isothermal–isobaric phase diagrams for the SmCoO3 - SmFeO3 - SrCoO3 -SrFeO3 system to the compositional square of metallic components was presented

STRUCTURE AND OXYGEN NONSTOICHIOMETRY OF COMPLEX OXIDES IN THE Ln – Ba – Fe – Co – O (LN=Dy, Ho)

Samples of overall composition Ba1-xLnxFe1-yCoyO3-δ and BaFe1–zLnzO3 δ (Ln=Dy, Ho) were prepared by glycerin nitrate technique. Structural parameters were refined using the Rietveld analysis. Oxygen content in the oxides has been determined by means of thermogra-vimetry and iodometric titration

Crystal Structure and Properties of Complex Oxides in the System Gd2O3-BaO-Fe2O3

Two types of phases: Ba1-хGdхFeO3-δ and BaGdyFe1-yO3-δ were obtained. The structural parameters of single-phase samples were refined by the Rietveld analysis. Oxygen content in single-phase oxides is determined by TGA and iodometric titration

Structure and Properties of Individual Phases in the Eu2O3-(Ba, Co)O-Fe2O3 Systems

The homogeneity ranges of solid solutions EuFe1-xCoxO3-δ and Ba1-xEuxFeO3-δ (0≤x≤1) in air have been determined. Thermal expansion, electrical conductivity and Seebeck coefficient were measured within the temperature range of 25-1100ºС in air.Работа выполнена при финансовой поддержке гранта Министерства науки и высшего образования России (Соглашение № 075-15-2019-1924)

PHASE EQUILIBRIA IN THE Pr2O3–BaO–Fe2O3 SYSTEM

A series of samples with different ratios of metal components was obtained using glyc-erol-nitrate technology at a temperature of 1100ºC. The subsolidus phase diagram for the ½ Pr2O3 – BaO – ½ Fe2O3 system at 1100°C in air has been constructed

Phase Equilibria in the Pr2O3-BаO-CoO System

A series of samples with different ratios of metal components was obtained using glycerin-nitrate technology at a 1100°C. The primary triangulation of the phase diagram of the ½ Pr₂O₃–BaO–CoO system at 1100°C in air has been constructed

CRYSTAL STRUCTURE AND PHYSICOCHEMICAL PROPERTIES OF EuCoXFe1-XO3-Δ (0≤X≤1) COMPLEX OXIDES

The XRD patterns of single phase EuFe1-xCoxO3-δ (0≤x≤1) solid solutions were indexed in the orthorhombic structure (sp. gr. Pbnm). Thermal expansion, electrical conductivity and Seebeck coefficient of EuFe1-xCoxO3-δ were measured within the temperature range of 25-1100ºС in air