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

Abstract

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.Keywords: phase equilibrium; manganites; isobaric-isothermal diagrams; solid solutions © Cherepanov V. A., Gavrilova L. Ya., Volkova N. E., Urusova A. S., Aksenova T. V., Kiselev E., 2015 IntroductionThe studies of phase equilibria in the systems based on rare earth elements and 3d transition metals and thermodynamic parameters of the oxide phases formed in these systems was initiated by Vladimir Mikhailovich Zhukovsky in 1977 under the direct supervision of Alexander Nikolaevich Petrov, as the development of contractual issues, conducted with an experienced company GIREDMET. The works on the study of the system Sm-Co-O and properties of oxide phases formed in system were then extended to other rare earth elements (REE) [1][2][3][4][5][6][7][8] and 3d transition metals [9][10][11][12][13]. A characteristic feature of these systems is the formation of oxide phases with perovskite structure AVO 3 and related. The partial substitution of rare earth elements in alkaline earth metals (AEM) leads to significant change of properties and they found a wide range of interesting for practical applications of the properties such as high conductivity up to the superconducting state, magnetic properties, catalytic activity of the processes of afterburning of exhaust gases and a variety of redox reactions, high mobility in the oxygen sublattice and more. In addition, partial substitution in the A-sublattice under constant 3d-cation in the systems Ln-T-O allows to stabilize the structure, which Cherepanov V. A., Gavrilova L. Ya., Volkova N. E., Urusova A. S., Aksenova T. V., Kiselev E. in the given conditions (temperature and oxygen pressure) are thermodynamically unstable. Therefore, further development of investigations of phase equilibria and thermodynamic stability of complex oxides were targeting the systems Ln-M-T-O (where Ln = REE, M = Ca, Sr, Ba; T = Mn, Fe, Co, Ni, Cu). When a certain percentage of similarity (in all possible formation of a phase with perovskite structure LnTO 3±d ) these systems still have a noticeable and distinctive features depending on the nature of the components. Phase equilibrium in systems with T = MnThe significant difference of perovskite phases in the manganese-containing systems Ln-Mn-O is that the oxygen content in them exceeds the stoichiometric air LnMnO 3+d . In fact, the oxygen sublattice is complete and the non-stoichiometry is realized by vacancy disordering ...

Anomalies of the electronic structure and physical properties of rare-earth cobaltites near spin crossover

“…В работе [100] также отмечается, что частичное замещение в А-подрешетке при неизменном 3d-катионе (В) в системах Ln x M 1−x СоО 3−δ позволяет стабилизировать термодинамически нестабильные структуры.…”

Phase equilibria, structure, oxygen nonstoichiometry, and thermal expansion of oxides in the 1/2Y2O3–SrO–1/2Fe2O3 system

“…The information concerning small‐sized rare earth‐ or yttrium‐based ferrites is limited, although undoped strontium ferrite and yttrium ferrite have been the objects of wide‐ranging studies as magnetic and membrane materials in the last few decades . The wide variety of specific features of phase formation in the related systems and significant differences in the phase diagrams of these systems require detailed study of each system, in particular Y 2 O 3 –SrO–Fe 2 O 3 .…”

Advancing Electrode Properties through Functionalization for Solid Oxide Cells Application: A Review

“…The high catalytic ORR/OER for such oxides are generally accredited through higher concentration of transportable species at AO‐planes [154] . Tailoring the characteristics of LnBaCo2O5+δ by replacement at A and/or B‐site can drastically accelerate the performance in SOFC/SOEC [155,156] . A detailed analysis on the performance evaluation and steadiness of Ca and Fe co‐doped δ layered perovskite (SmBa 0.75 Ca 0.25 CoFeO 5+ ) under cathodic and anodic bias of 200 mV is studied for ORR and OER at a constant 216 h at 800 °C [157] .…”

“…[154] Tailoring the characteristics of LnBaCo2O5 + δ by replacement at A and/or B-site can drastically accelerate the performance in SOFC/SOEC. [155,156] A detailed analysis on the performance evaluation and steadiness of Ca and Fe co-doped δ layered perovskite (SmBa 0.75 Ca 0.25 CoFeO 5 + ) under cathodic and anodic bias of 200 mV is studied for ORR and OER at a constant 216 h at 800 °C. [157] A highly efficient and durable bi-functional air electrode PrBa 0.9 Co 1.96 Nb 0.04 O 5 + δ for reversible SOC application with associated OER and/or ORR has also been demonstrated for its excellent electrochemical performance having a degradation of 40 mV over 1000 h for H 2 O electrolysis.…”