Ceria-based materials for high-temperature electrochemistry applications

This paper describes the experimental studies of multi-component solid state electrolytes based on CeO2 and their application in intermediate temperature electrochemical devices. Two important aspects are emphasized: the effect of different dopants’ ionic radius and concentration on the electrical properties of CeO2-based solid solutions in air and the influence of combined dopants on the electrolytic properties of solid electrolytes from the standpoint of the critical oxygen partial pressure pO2 at which point the values of the electronic and ionic components of conductivity are equal. Examples of usage of the developed multi-component Ce0.8(Sm0.75Sr0.2Ba0.05)0.2O2-δ electrolyte synthesized by solid state, laser evaporation and combustion methods and composites on the base of Ce0.8(Sm0.8Sr0.2)0.2O2−d electrolyte as a component of electrochemical devices such as solid oxide fuel cell, gas sensors and as a component of the mixed ionic and electronic conducting (MIEC) membranes for hydrogen and syngas gas production are cited.The present work was financially supported by Russian Foundation for Basic Research and Government of Sverdlovsk region, grant no. 13-03-96098

On the chemical stability of the structure and physical characteristics of the high-temperature spintronic composite EuO:Fe under normal conditions

The possibility of forming a limited solid solution Eu 1-x Fe x O in the structure of a spintronic composite material EuO:Fe obtained by the high-temperature solid-phase reduction method of a mixture of higher metal oxides is discussed. Its prevailing role in the formation of outstanding physical properties of this composite as a high-temperature spin injector is described from experimental and theoretical data. © 2018 Russian Academy of Natural Science. All Rights Reserved

The development of electrolytes for intermediate temperature solid oxide fuel cells

This report describes a number of experimental studies on the solid state electrolytes for intermediate temperature solid oxide fuel cells (IT-SOFCs): Ce1-xLnxO2-δ (Ln = La, Nd, Sm, Eu, Gd, Dy, Ho, Er, Yb), some multicomponent systems Ce1-xLnx/2Ln x/2O2-δ (x = 0 - 0.20; Ln = Sm, La, Gd and L'n = Dy, Nd, Y), some systems with simultaneous doping by rare earth and alkali earth elements Ce0.8(Sm1-xMx)0.2O2-δ (M = Ca, Sr; x = 0.0 - 1.0) and Ce0.8(Sm1-x-yBayMx)0.2O2-δ (M = Ca, Sr; x = 0, 0.15, 0.20; y = 0.05, 0.1). Two important aspects are emphasized: the effect of different dopants' ionic radius and concentration on the electrical properties of CeO2 based solid solutions and the influence of the method of preparation on the structural properties of ceria ceramics and the electrochemical performance of single SOFCs on their base. To describe the electrolytic properties of solid electrolytes the notation of the electrolytic domain boundary (EDB) - the critical oxygen partial pressure P*O2 at which the values of the electronic and ionic components of conductivity are equal, were calculated and presented. The interpretation of these data will lead to a better understanding of, subsequent improvements to and ultimately, the commercialization of IT-SOFCs in Russia. © 2014 WIT Press.International Journal of Safety and Security Engineering;International Journal of Sustainable Development and Planning;WIT Transactions on Ecology and the Environmen

Solution combustion synthesis of α-Al2O3 using urea

The processes involved in the solution combustion synthesis of α-Al2O3 using urea as an organic fuel were investigated. The data describing the influence of the relative urea content on the characteristic features of the combustion process, the crystalline structure and the morphology of the aluminium oxide are presented herein. Our data demonstrate that the combustion of stable aluminium nitrate and urea complexes leads to the formation of α-alumina at temperatures of approximately 600-800 °C. Our results, obtained using differential thermal analysis and IR spectroscopy methods, reveal that the low-temperature formation of α-alumina is associated with the thermal decomposition of an α-AlO(OH) intermediate, which was crystallised in the crystal structure of the diaspore. © 2012 Elsevier Ltd and Techna Group S.r.l

Spin transistor in the EuO:Fe/GaAs contact

Spin-wave structures with magnetic-field-driven current-voltage characteristics at room temperature were produced using a spintronic europium-monoxide-based thin-film emitter and a single-crystal n-GaAs semiconductor collector. This manifests practical implementation of the spin current transport and creation of a high-temperature spin transistor with the magnetic semiconductor/nonmagnetic semiconductor contact. © 2011 Pleiades Publishing, Ltd

Ferromagnetic composite material for spintronics

Translated from Doklady Akademii Nauk, Vol. 402, No. 3, 2005, pp. 181–183

Effect of dopants on CeO2 based solid state electrolytes for intermediate temperature electrochemical devices

The present work aims at the investigation of the influence of different dopants' ionic radii and their concentration on both the lattice parameters and the density of Ce1-xLnxO2-δ (x = 0-0.20; Ln = La, Nd, Sm, Eu, Gd, Dy, Ho, Er, Yb) solid solutions, multi-component Ce1-xLnx/2Ln'x/2O2-δ (x = 0-0.20; Ln = Sm, La, Gd and Ln' = Dy, Nd, Y), Ce0.8(Sm 1-xMx)0.2O2-δ (M= Ca, Sr, x=0.0-1.0) and Ce0.8(Sm1-x-yBayM x)0-2O2-δ (M=Ca, Sr, x=0, 0.15, 0.20; y=0.05, 0.1) systems. The electrical conductivity measurements of the samples were carried out by using the four-point dc technique in different atmospheres. Temperature and oxygen partial pressure were varied automatically by means of microprocessor system ZIRKONIA-318 in the range of 623-1173 K and 0.1-10 -23 atm, respectively. To describe the electrolytic properties of solid electrolytes the notation of the EDB (electorytic domain boundary) - the critical oxygen partial pressure (PO2*) at which the values of the electronic and ionic components of conductivity are equal- is often used. The values of the critical partial pressure of oxygen for different compositions at 1023 K were calculated from dependences of total conductivity vs. oxygen partial pressure in proposal that ionic conductivity depends on dopand's concentration, but isn't influenced by PO2