Showing papers in "Solid State Ionics in 1995"

TL;DR: In this article, the electrical conductivity and Seebeck coefficient as a function of the Co Fe ratio and temperature were investigated in the La0.8Sr0.2Co1−yFeyO3 with 0 ≤ y ≤ 1.

TL;DR: In this paper, a semi-empirical model was developed which took into account the thermally activated disproportionation of Co 3+ ions into Co 4+ and Co 2+ pairs, and the ionic compensation of oxygen vacancies formed at high temperatures.

TL;DR: In this article, the perovskite-type oxide solid solutions based on cerate or zirconate were used as a solid electrolyte for detecting hydrogen and other hydrogen-containing compounds.

TL;DR: In this paper, the evolution of transport properties with temperature is discussed in relation to structure, revealing a series of phase transitions between ambient temperature and 1000 °C, which is confirmed by measurement of water vapour transfer in a cell in which the perovskite is exposed to wet hydrogen on both sides.

TL;DR: In this paper, the phase diagram of SrCo 0.80 Fe 0.20 O 3 − δ membranes was discussed in relation to the phase diagrams of the surface exchange process, and it was shown that surface exchange is the rate limiting step in the overall permeation mechanism.

TL;DR: The ionic conductivities of cerium oxide doped with oxides of the entire rare earth series (except Pm) were measured using ac impedance in air at temperatures ranging from 400 °C to 900 °C as mentioned in this paper.

TL;DR: In this article, Li1 − zNi1 + xO2 with various x values were synthesized and their electrochemical properties, phase transitions, and ordering phenomena were investigated comparatively.

TL;DR: In this article, a review of perovskite-structured oxides found to be high-temperature protonic conductors is presented, and a simple first-order model is given to serve as a basis for consideration of various fundamental aspects of these conductors, such as the nature of proton incorporation by exposure to water vapor at high temperatures, the environment in which protons are located in the lattice, and the way proton migration.

TL;DR: The crystal structure and properties of La1 − xSrxCoO3 − y with strontium contents ranging from 0.1 to 0.7 have been studied in this paper.

TL;DR: In this paper, reversible lithium deintercalation of chromium-substituted spinel manganese oxides LiMn2 − yO4 (0 ≤ y ≤ 1) in the voltage range 3.4-5.4 V versus Li, occurs in two main steps for 0 < y < 1: one at about 4.9 V and the other at approximately 4 V.

TL;DR: In this paper, the conductance of Nafion membranes was investigated by means of impedance spectroscopy as a function of temperature and sample treatment, and an Arrhenius-type analysis showed two regimes, with a change in activation energy observed at transition temperatures between 225 and 260 K which depends on the water content.

TL;DR: In this paper, the electrical conductivity change with annealing at 1000 °C in the Yb 2 O 3 ZrO 2 (YbSZ) and Sc 2 O3 -Zr O 2 (ScSZZ) systems were examined.

TL;DR: In this article, a simple equivalent circuit has been used to identify experimentally accessible parameters which may control the oxygen flux through a variety of technological devices, in particular the oxygen surface exchange coefficient (k cm s−1), which can be determined by isotopic exchange measurements is proportional to a characteristic electrode current density (jEA cm−2) which determines the electrode resistance (RE Ωcm2).

TL;DR: In this article, the effects of the addition of small amount of rare earth cations were investigated for the suppression of hole conduction in the high oxygen partial pressure range, with La 0.8 Sr 0.2 Ga 0.

TL;DR: In this paper, the deintercalation process and magnetic properties were clarified for lithium nickel oxides with different sample compositions which were characterized by neutron and X-ray diffraction measurements, and their interactions were discussed on the basis of weak magnetic-field magnetization measurements.

TL;DR: In this paper, the role of the oxygen vacancies with respect to the ionic conductivity in perovskites and brownmillerite phases is discussed in detail, and the structures of these phases containing oxygen vacancies are surveyed.

TL;DR: In this article, electrical conductivity measurements are reported on the rare earth pyrochlore compound Gd2Ti2O7 as a function of temperature, oxygen partial pressure and aliovalent dopant concentration.

TL;DR: In this paper, the authors used Wagner theory in conjunction with data of oxygen nonstoichiometry and vacancy diffusion coefficients from literature, and found that the experimental flux values deviated from the model calculations with factors up to 2.5.

TL;DR: A nearly single-phase θ-Al2O3 scale has been grown on two FeCrAl alloys, according to a time-temperature-transformation relationship for the formation of external alumina scales as mentioned in this paper.

TL;DR: In this article, the role of grain boundary phases and their influence on grain boundary resistivity in ZrO 2 -based electrolyte systems have been investigated by impedance spectroscopy and microstructural analysis.

TL;DR: LaPO 4 with nominally 5 atom% Ca or Sr was synthesised using co-precipitation, cold-pressed to bars, and sintered at 1300 °C as mentioned in this paper.

TL;DR: In this paper, a galvanic cell type of hydrogen sensor was developed using CaZrO3-based proton conductor as a solid electrolyte, which could be used for the accurate determination of hydrogen concentration in molten aluminum alloys.

TL;DR: In this article, the electrical conductivity of monocrystalline (3.0, 9.5, 12.0 and 17.9 mol% yttria)-doped zirconia samples was studied using impedance spectroscopy in the temperature range of 250-1200 °C.

TL;DR: In this article, the intrinsic grain-boundary resistivity in stabilized-ZrO 2 was considered to originate from the V O depletion in the space-charge layers, and a model was developed.

TL;DR: In this paper, rare earth or alkaline earth oxide-substituted ceria (CeO 2 ) powders were successfully prepared via hydrothermal synthetic route.

TL;DR: In this article, the elementary steps of proton conductivity in oxides, proton transfer and hydroxyl ion reorientation, are investigated and the anticipated H D isotope effects of their rates are compared to those of Proton (deuteron) conductivity.

TL;DR: In this paper, photo-cross-linking reactions of three different polyether triacrylate oligomers in the presence of lithium salts were performed to obtain network polymer electrolytes.

TL;DR: In this article, the deviation from stoichiometry in (CrxFe1−x)3−δO4 was measured by thermogravimetry at 1200 °C as a function of oxygen activity, aO2, and cationic composition.

TL;DR: In this paper, a defect chemistry model is proposed for brownmillerite oxides with high oxygen ion conductivity, and its electrical conductivity and transport properties have been studied in detail.

TL;DR: In this article, a tubular fixed bed reactor at various temperatures was used to study the reaction of the non-stoichiometric iron oxide Fe1−yO and mixed iron manganese oxides (Fe1−xMnx)1−YO (x ≤ 0.3) by water.