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Although cobalt-containing cathode materials are widely used in protonic ceramic fuel cells (PCFCs) because of its high catalytic activity, cobalt diffuses into the proton-conducting electrolyte, thereby decreasing the power generation performance. To achieve a higher power generation performance in PCFCs with a cobalt-free cathode, we fabricate anode-supported PCFCs using BaZr0.8Yb0.2O3–δ as the electrolyte, and composite cathodes of La0.65Ca0.35FeO3−δ (LCaF) and BaZr0.1Ce0.7Y0.1Yb0.1O3−δ (BZCYYb). The mixing weight ratios of LCaF and BZCYYb are varied to 80:20, 70:30, 60:40, 50:50, and 30:70. The PCFC with LCaF–BZCYYb (60:40) composite cathode exhibits the highest power generation performance in the operating temperature range of 500–700 °C with a maximum power density (MPD) of 0.41 W cm−2 at the operating temperature of 600 °C. This MPD value is higher than that obtained in our previous study using a PCFC with a La0.6Sr0.4Co0.2Fe0.8O3−δ –BZCYYb composite cathode.

The crystal structures, thermal expansions, chemical expansions, and CO2 resistances of Ba(Ce0.7Zr0.1Y0.1Yb0.1)O3-δ (BCZYYb7111) and Ba(Ce0.4Zr0.4Y0.1Yb0.1)O3-δ (BCZYYb4411) have been investigated via high-temperature X-ray diffraction (HT-XRD) in controlled atmospheres (dry N2, wet N2, and dry 33.3 vol% CO2 - 66.6 vol% N2) on cooling from 1173 to 298 K. Two phase transitions, cubic to trigonal and trigonal to monoclinic, were observed for BCZYYb7111, whereas one phase transition, cubic to trigonal for BCZYYb4411. BCZYYb7111 and BCZYb4411 exhibited the linear thermal expansion coefficients of 10.6 × 10-6 K-1 and 9.8 × 10-6 K-1 between 773 and 1173 K in dry N2, respectively. The maximum chemical expansion rates of 0.33 % and 0.30 % were observed at 773 K for BCZYYb7111 and BCZYYb4411, respectively. BCZYYb4411 having lower Ce/Zr ratio and higher symmetry showed higher CO2 resistance than BCZYYb7111.

In light emitting diodes, Y3Al5O12:Ce (YAG:Ce) is used as a yellow phosphor in combination with blue LEDs but lacks a red component in emission. Therefore, considerable efforts have been directed toward shifting the emission of YAG:Ce to longer wavelengths. In this study, a Y3Al5O12 (YAG) crystal incorporating a high content of Ce, (Y1−xCex)3Al5O12 (0.006 ≦ x ≦ 0.21), was successfully prepared by a polymerized complex method in which low-temperature annealing (650–750 °C) was employed prior to sintering at 1080 °C. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis indicated that the obtained sample was a single phase YAG crystal with x ≤ 0.21. Interestingly, orange-red emission was observed with x ≥ 0.07 with UV-blue light irradiation. With excitation at 450 nm, the emission peak increases from 538 nm (x = 0.006) to 606 nm (x = 0.21). This massive red shift in the high-x region was not observed without the 1st step of low-temperature annealing, which implied that low-temperature annealing was essential for incorporating a high concentration of Ce. The precursor formed by low-temperature annealing was amorphous at x = 0.04, whereas CeO2 nanocrystals were formed in the amorphous material with x ≥ 0.11, based on the XRD and TEM results. CeLIII X-ray absorption edge structure revealed that Ce existed as Ce4+ in the precursor and Ce3+ in the obtained crystal. It was speculated that CeO2 was formed at low temperature, releasing oxygen, with sintering at 1080 °C, leading to the incorporation of Y3+ in the Ce–O framework. The lattice constant increased significantly from 12.024 A to 12.105 A with increasing x, but the crystal field splitting did not increase and was constant from x = 0.06 to x = 0.21. Hence, the massive red shift in emission was not explained by the large crystal field splitting, but instead by the Stokes shift.

Perovskite oxides ABO3 (A = Sr, Ba, B = Ti, Zr, Hf) were prepared at around room temperature using the reaction between alkaline earth hydroxides and metal oxide hydrous gels. The products of the reaction crystallized without any calcination. High-symmetry perovskite oxides, such as cubic perovskite, were obtained at lower temperatures. The Madelung energy of each perovskite oxide was calculated from the crystal structure and the lattice parameter obtained by XRD measurement. The calculated Madelung energy change in the synthesis reaction showed a linear relationship with the synthesis temperature. A rise in the synthesis temperature increased the change of the Madelung energy. The results thus confirmed that the synthesis temperature depended on the symmetry of the perovskite oxide in this study. Drawing from these results, we concluded that the synthesis temperature could be estimated by considering the crystal structure and Madelung energy change in the synthesis reaction.

Acids such as aqua regia, a 3:1 mixture of hydrochloric acid (HCl) and nitric acid, that contain strong oxidizing agents are used in the dissolution-based recovery of platinum group metals (PGMs). However, nitrate-nitrogen emission has become subject to increasingly strict environmental regulations in recent years. Accordingly, we herein propose a dissolution process for PGMs via the formation of complex oxides using HCl alone. We prepared complex oxides of alkali metals and rhodium (Rh), which is particularly hard to dissolve, and investigated their dissolution behaviors in HCl. Rh-containing complex oxides were prepared by calcining Rh powder and alkali metal salts in air, and dissolution tests using HCl were conducted on the complex oxides obtained. It was found that Rh-containing complex oxides were completely dissolved under appropriate calcination and dissolution conditions.

Extended X-ray absorption fine structure (EXAFS) analyses of the Eu2Zr2O7 and La2Zr2O7 pyrochlore composition oxides were performed to examine differences in the local structures around the Zr atoms. In the EXAFS analyses of Eu2Zr2O7, the amplitude reduction factor of Zr16c-O8a was considerably large, indicating that a part of the oxygen vacancy site (8a) was occupied by oxide ions. Furthermore, the occupancy of the 8a site determined by Rietveld refinement of the X-ray diffraction data for Eu2Zr2O7 was 0.32(2), which was consistent with the EXAFS results. From the EXAFS analyses of La2Zr2O7, oscillation in the high wavenumber k-range sharpened with decreasing temperature, and the mean square relative displacement (MSRD) values of the Zr O peak in the R-space were small compared to those of Eu2Zr2O7. Therefore, the disorder in the local structures around the Zr atoms of La2Zr2O7 was determined to be smaller than that of Eu2Zr2O7.

Although protonic ceramic fuel cells (PCFCs) have a great potential to realize higher energy-conversion efficiency compared with all other conventional devices, actual PCFCs have shown current leakage loss due to their intrinsic transport property with electron-hole conduction of proton-conducting electrolytes, resulting in a decrease in efficiency. The present study shows a new finding that open-circuit voltage (OCV), which is an indicator of current leakage loss, depends on the ratio of the electrode polarization resistance to the electrolyte ohmic resistance within a PCFC and experimentally demonstrates improvement in OCV by developing high-performance cathode and anode. Results show that our anode-supported PCFC with BaZr0.1Ce0.7Y0.1Yb0.1O3−δ electrolyte and high-performance electrodes achieves extremely high OCV, e.g., 1.112 V at 600 °C (≈ 98% of the theoretical OCV) and 1.132 V at 550 °C (≈ 99% of the theoretical OCV). Compared with recently reported OCVs for PCFCs, these measured OCVs are remarkabl...

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Solid oxide electrolysis cells can theoretically achieve high energy-conversion efficiency, but current density must be further increased to improve the hydrogen production rate, which is essential to realize widespread application. Here, we report a structure technology for solid oxide electrolysis cells to achieve a current density higher than 3 A cm−2, which exceeds that of state-of-the-art electrolyzers. Bimodal-structured nanocomposite oxygen electrodes are developed where nanometer-scale Sm0.5Sr0.5CoO3−δ and Ce0.8Sm0.2O1.9 are highly dispersed and where submicrometer-scale particles form conductive networks with broad pore channels. Such structure is realized by fabricating the electrode structure from the raw powder material stage using spray pyrolysis. The solid oxide electrolysis cells with the nanocomposite electrodes exhibit high current density in steam electrolysis operation (e.g., at 1.3 V), reaching 3.13 A cm−2 at 750 °C and 4.08 A cm−2 at 800 °C, corresponding to a hydrogen production rate of 1.31 and 1.71 L h−1 cm−2 respectively., High-temperature solid oxide electrolysis cells are a promising technology for energy conversion, but higher current density is needed to increase efficiency. Here the authors design nanocomposite electrodes to improve electronic and ionic conductivity to achieve a high current density.

An improved method to correct observed shift and asymmetric deformation of diffraction peak profile caused by the axial-divergence aberration in Bragg–Brentano geometry is proposed. The method is based on deconvolution–convolution treatment applying scale transform of abscissa, Fourier transform, and cumulant analysis of an analytical model for the axial-divergence aberration. The method has been applied to the powder diffraction data of a standard LaB6 powder (NIST SRM660a) sample, collected with a one-dimensional Si strip detector. The locations, widths and shape of the peaks in the deconvolved–convolved powder diffraction data have been analyzed. The finally obtained whole powder diffraction pattern ranging from 10° to 145° in diffraction angle has been simulated by the Pawley method applying a symmetric Pearson VII peak profile model to each peak with ten background, two peak-shift, three line-width, and two peak-shape parameters, and the Rp value of the best fit has been estimated at 4.4%.

Four series of small parasite peaks observed in powder diffraction data recorded with a Cu-target X-ray tube and a Ni filter on the diffracted beam side in Bragg–Brentano geometry are investigated. One series of the parasite peaks is assigned to the tungsten Lα-emission. Other three types of the parasite peak series are likely to be caused by the K-emissions of Ni, but the peak locations are deviated from those predicted by the Bragg's law. An empirical formula to locate the parasite peaks and a method to remove them from observed powder diffraction data are proposed. The method is based on the whole-pattern deconvolution–convolution treatment on the transformed scale of abscissa. The parameters optimized for the diffraction data measured for Si powder has been applied on treatment of the data of LaB6 powder recorded under the same experimental conditions. It has been confirmed that the parasite peaks in the observed data can effectively be removed by the deconvolution treatment with parameters determined by a reference measurement.

A method to remove small CuKβ peaks and step structures caused by NiK-edge absorption as well as CuKα2 sub-peaks from powder diffraction intensity data measured with Cu-target X-ray source and Ni-foil filter is proposed. The method is based on deconvolution–convolution treatment applying scale transform of abscissa, Fourier transform, and a realistic spectroscopic model for the source X-ray. The validity of the method has been tested by analysis of the powder diffraction data of a standard LaB6 powder (NIST SRM660a) sample, collected with the combination of CuKα X-ray source, Ni-foil Kβ filter, flat powder specimen and one-dimensional Si strip detector. The diffraction intensity data treated with the method have certainly shown background intensity profile without CuKβ peaks and NiK-edge step structures.

Diffusion behavior of Ni during high temperature co-sintering was quantitatively investigated for anode-supported solid oxide fuel cells (SOFCs) that had BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3− δ (BZCYYb) proton-conducting electrolyte and NiO-BZCYYb anode. Although diffused Ni in such SOFCs effectively acts as a sintering aid to densify the BZCYYb electrolyte layer, it often negatively affects the electrolyte conductivity. In the present study, field emission electron probe microanalysis (with wavelength dispersive X-ray spectroscopy) clearly revealed that Ni diffused into the BZCYYb electrolyte layer, and that the amount of diffused Ni increased with increasing co-sintering temperature. In particular, relatively high Ni concentration within the electrolyte layer was observed near the electrolyte/anode interface, e.g., approximately 1.5 and 2.8 wt% at co-sintering temperature of 1300 and 1400 °C, respectively. Electrochemical measurements showed that, compared with the lower co-sintering temperatures (1300–1350 °C), the highest co-sintering temperature (1400 °C) led to the highest ohmic resistance because of lower electrolyte conductivity. These results suggest that high co-sintering temperature causes excessive Ni diffusion into the BZCYYb electrolyte layer, thus degrading the intrinsic electrolyte conductivity and consequently degrading the SOFC performance.

Widespread application of PCFCs will require higher performance even at lower temperatures (0.1Ce0.7Y0.1Yb0.1O3–δ (BZCYYb1711) functional interlayer and a BaZr0.8Yb0.2O3−δ (BZYb20) electrolyte. In this PCFC, a zirconate-based oxide with high durability against CO2, BZYb20, is selected as the electrolyte material, and a BZCYYb1711 functional interlayer is applied between the dense BZYb20 electrolyte and a cathode to achieve higher power density and higher open-circuit voltage (OCV) of the PCFC. In cell fabrication via conventional wet process and co-sintering, although Ni diffusion occurs from NiO-BZYb20 anode into the approximately 8-μm-thick BZYb20 electrolyte, almost no Ni diffuses into the BZCYYb1711 functional interlayer. Compared to a PCFC without this functional interlayer, the proposed PCFC exhibits higher electrochemical performance. Results showed that the BZCYYb1711 functional interlayer reduces cathode polarization resistance and increase power density of the PCFC. Moreover, the OCV increases because the BZCYYb1711 functional interlayer suppresses the current leakage caused by hole conduction of the BZYb20 electrolyte. In conclusion, this bi-layered structure effectively improves both the power density and OCV of PCFCs.

This paper reports our development of protonic ceramic fuel cells (PCFCs) with BaZr0.8Yb0.2O3−δ (BZYb) electrolyte. Although PCFCs can theoretically achieve ultra-high energy-conversion efficiency for power generation, higher power density even at lower temperatures below 600°C is required to widespread application. Here, a zirconate-based oxide of BZYb was selected as electrolyte material of PCFCs because of its high chemical stability against CO2. Also, cost-effective conventional wet processes were used to fabricate the PCFCs. High-temperature co-sintering successfully produced a dense and thin BZYb electrolyte. The PCFC showed a stable operation for 400 h without significant degradation. Investigation into changing parameters of large-size PCFCs (50 × 50 mm) such as anode porosity, interlayer function, electrolyte thickness, and cathode material improved the power density of the PCFCs with BZYb electrolyte. At 600°C, the power density reached 0.38 and 0.48 W cm−2 at 0.85 and 0.75 V, respectively.

A multi-layered electrolyte structure is proposed for proton-conducting solid oxide fuel cells (SOFCs) to achieve higher power density and higher open-circuit voltage (OCV). Although recent proton-conducting SOFCs have demonstrated high power density, their OCVs have been lower than that of conventional SOFCs with stabilized zirconia because proton-conducting oxides intrinsically have electron-hole conduction. The proposed electrolyte structure has a porous BaZr0.1Ce0.7Y0.1Yb0.1O3–δ (BZCYYb) layer deposited on a dense BZCYYb layer. This structure effectively improves both cathode polarization and ionic transport property, resulting in higher power density with higher OCV. Also, discussion based on an equivalent circuit model of proton-conducting SOFCs clearly reveals a mechanism that determines OCV, namely, higher ohmic resistance and lower electrode polarization resistance lead to higher OCV. Our results suggest that higher electrode performance is essential for proton-conducting SOFCs to achieve higher OCV, particularly in the case of anode-supported configurations with thin electrolyte.

A solid oxide fuel cell (SOFC) for high power density operation was developed with a microstructure-controlled cathode using a nano-composite powder of Sr-doped LaMnO 3 (LSM) and Y 2 O 3 -stabilized ZrO 2 (YSZ) synthesized by spray pyrolysis. The individual LSM-YSZ nano-composite particles, formed by crystalline and amorphous nano-size LSM and YSZ particles, showed spherical morphology with uniform particle size. The use of this powder for cathode material led to an extremely fine microstructure, in which all the LSM and YSZ grains (approximately 100–200 nm) were highly dispersed and formed their own network structures. This microstructure was due to the two phase electrode structure control using the powder, namely, nano-order level in each particle and micro-order level between particles. An anode-supported SOFC with the LSM-YSZ cathode using humidified H 2 as fuel and ambient air as oxidant exhibited high power densities, such as 1.29 W cm −2 under a voltage of 0.75 V and a maximum power density of 2.65 W cm −2 at 800 °C. Also, the SOFC could be stably operated for 250 h with no degradation, even at a high temperature of 800 °C.

We measured the coefficient of thermal expansion (CTE) of conducting composite ceramics 30 vol.% CuO-mixed CaCu3Ru4O12 together with CaCu3Ru4O12 and CuO. Although conducting ceramics tend to show higher CTE values than insulators, and its CTE value does not match with other ceramic materials, the CTE of CaCu3Ru4O12 (7&ndash, 9 &times, 10&minus, 6/K) was as small as those of insulators such as CuO (9 &times, 6/K), alumina (8 &times, 6/K), and other insulating perovskite oxides. We propose that the thermal expansion of CaCu3Ru4O12 was suppressed by the Cu-O bond at the A-site due to the Jahn&ndash, Teller effect. This unusually small CTE of CaCu3Ru4O12 compared to other conducting oxides plays a vital role enabling successful coating of 30 vol.% CuO-mixed CaCu3Ru4O12 thick films on alumina substrates, as demonstrated in our previous study.

The crystal structures of H 2 O treated 20 mol% Sr-doped LaScO 3 perovskite-type oxide, (La 0.8 Sr 0.2 )ScO 3 H 0.18 (LSS) have been investigated at 3, 150, and 298 K using a powder neutron diffraction (ND) method. All the diffraction peaks of LSS could be indexed as an orthorhombic GdFeO 3 -type perovskite structure (space group: Pnma , No.62) between 3 and 298 K. The Rietveld refinement and subsequent maximum-entropy-method (MEM) analysis results of ND data at 3 K revealed that protons are associated with the O1 oxygen (4 c ) site in the La and Sr containing mirror plane and exist in the space consists of two tilting ScO 6 octahedra. The O1 H bond distance was found to be 1.12(2) A at 3 K.

Crystal structures of Nd2Zr2O7 were refined by the Rietveld analysis of neutron diffraction data at 1098, 1217, 1348 and 1467 K, while those of La2Zr2O7 were refined at 1070, 1188, 1306 and 1435 K. Nd2Zr2O7 had the pyrochlore-type structure with the oxygen vacancy distributed over all oxide-ion sites between 1098 and 1467 K. On the other hand, La2Zr2O7 had the pyrochlore-type structure with almost complete ordering for oxygen vacancy up to 1070 K. The change in oxide-ion conductivity (σ) in Nd2Zr2O7 and La2Zr2O7 can be related to a change in the product of site occupancy (g48f) and the oxygen vacancy rate (1-g48f) in the O3 (48f) site, g48f(1-g48f).

It was found that oxide-ion conductivity of Nd-doped CeO2 (Ce1-xNdxO2-x/2) increased with an increase in Nd content x up to x = 0.2, showing a maximum value at x = 0.2, and then decreased with x. In order to clarify the origin of the decrease in the conductivity of the heavily Nd-doped CeO2, Rietveld analyses of the X-ray diffraction and neutron diffraction data were carried out, assuming two phases with oxygen deficient fluorite-type and rare-earth C-type structures (0.45 ≤ x ≤ 0.7). The oxide-ion conductivity of the heavily Nd-doped CeO2 is discussed in relation to the formation of the rare-earth C-type structure, which derives from the oxygen ordering of the defect fluorite-type structure.

Perovskite-type proton conductors can be used as the electrolyte materials in fuel cells, hydrogen sensors, hydrogen separation apparatus, and the other electrochemical devices. In this paper, the crystal structure analysis of perovskite-type proton conductors under cell operating conditions by using a laboratory X-ray diffractometer with a parallel beam optics are introduced. The crystal structures of A3+B3+O3-type perovskite proton conductors, (La0.9Sr0.1) MIIIO3-δ (MIII=Sc, In, and Lu) are reported, and the expected change in proton conduction path is discussed with an increase in tilting angles of BO6 (=MIIIO6) octahedra. In addition, the electron density distribution of (La0.8Sr0.2) ScO3-δ compound is shown.

We have found a new route for preparing Pt containing perovskites. Ba containing perovskite powder, (La0.7Sr0.2Ba0.1)ScO3–δ (LSBS), reacted with Pt foil at 1898 K in air, and formed ultramarine colored Pt containing perovskite, (La0.7Sr0.2Ba0.1)(Sc,Pt)O3–δ, without changing the GdFeO3-type structure. The chemical compositions of the samples before and after firing, measured with inductively coupled plasma (ICP) optical emission spectrometry, were La: Sr: Ba: Sc = 0.70(1): 0.206(4): 0.101(2): 0.98(2) and La: Sr: Ba: Sc: Pt = 0.70(1): 0.197(4): 0.085(2): 0.95(2): 0.0062(2), respectively. The reaction proceeded not only at the interface between perovskite powder and Pt foil, but also over whole powder surface. We name this new preparation method the “solid-phase elution (SE) method”, because the process involves elution of Pt ions from the Pt foil to the LSBS perovskite lattice. It is expected that we can control the amount of Pt introduced into perovskites by using the SE method after optimizing the reaction time and temperature.

We report a juvenile case of diffuse sclerosing osteomyelitis of the mandible that showed a favorable response to pamidronate, a bisphosphonate derivative. Although conventional treatments had been ineffective for five years, pamidronate administration brought about conspicuous improvement both clinically and radiographically. Severe adverse reaction was not found except for low-grade fever and lassitude only on the day following administration. During the course of the treatment, however, nonsuppurative osteomyelitis of the right humerus also occurred, leading to the established diagnosis of chronic recurrent multifocal osteomyelitis. Then, pamidronate therapy was again performed successfully with almost disappearance of clinical symptoms. Both bone-specific alkaline phosphatase (bone formation marker) and pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICPT) (bone resorption marker) showed a marked decrease with pamidronate therapy, which suggested that pamidronate is useful for the treatment of chronic recurrent multifocal osteomyelitis with inhibitory effect on bone turnover.

It has been found that Pt eluted into the (La0.7Sr0.2Ba0.1)ScO3-δ perovskite oxide exhibited higher catalytic activity for CO oxidation than for H2 oxidation under separate reaction conditions, a behaviour which differs from that of conventional Pt catalysts. The unique activity appeared when ionic Pt in the perovskite lattice was partly reduced, forming Pt nanoparticles on the surface.

Transport properties of A 2+ B 4+ O 3 -type perovskite, Ba(Zr 0.8 Y 0.2 )O 3 − δ (BZY82) dense ceramics were investigated under controlled atmospheres between 423 and 1273 K. The “charge carrier map” of BZY82 has been prepared, which shows the predominant proton, oxide ion, and hole conduction domains. The predominant proton conduction appeared below 873 K in the presence of water vapor and/or hydrogen. The proton conductivity was 4.2 × 10 − 3 S/cm at 873 K and the apparent activation energy for proton conduction was 0.38 eV between 723 and 873 K in wet 40% H 2 atmosphere ( P (H 2 O) = 0.042 atm). The BZY82 also showed predominant oxide-ion conduction under dry and low P (O 2 ) conditions. The oxide-ion conductivity was 4.1 × 10 − 3 S/cm at 1273 K. The higher apparent activation energy for oxide-ion conduction of 0.75 eV was presumed to arise from the local distortion of BO 6 octahedra introduced by the mismatch of large Y 3+ ions (0.90 A) doping to Zr 4+ (0.72 A) sites and by the nature of Y 3+ ions trying to keep the C-type (cubic) earth structure.

The relationship between oxide-ion conductivity and ordering of oxide ion in the (Y 1− x La x ) 2 (Ce 1− x Zr x ) 2 O 7 system having a pyrochlore-type composition was investigated. The crystal phase of the system with a variable cation radius ratio, but with a constant lattice parameter, changed from a rare-earth-C (C)-type phase to a pyrochlore (P)-type phase through a fluorite (F)-type phase with increase in the composition ( x ), depending on the cation radius ratio r (A 3+ )/ r (B 4+ ), which is a measure of ordering degree of oxygen vacancies. The oxide-ion conductivity increased once up to x = 0.15, and then decreased with increasing x . This change of the electrical conductivity was understood on the basis of the ordering degree of oxide ion. The Rietveld analyses of X-ray and neutron diffraction patterns, and Raman spectroscopy supported the ordering effect of oxide ion on the conductivity.

Lanthanum-containing perovskites, LaMO3 (M=Al, Sc, Cr, Mn, Fe, Co, Ni, Ga, and In), have been synthesized in molten carbonates from a mixture of lanthanum carbonate and an M-containing oxide or an acetate, or from a co-precipitation mixture of metal (M) and lanthanum. Metal aluminum, chromium, and iron, immersed in a mixture of molten (Li0.52Na0.48)2CO3 and lanthanum carbonate at 923 K, were covered, respectively, with LaAlO3, LaCrO3, and LaFeO3. Ceramic and single-crystal α-Al2O3, immersed in molten (Li0.52Na0.48)2CO3 mixed with lanthanum carbonate, were also covered with LaAlO3. In situ X-ray diffractometry revealed that La2O2CO3 reacted with α-LiAlO2 to yield LaAlO3; the reaction proceeded faster under N2 than under a CO2 atmosphere.

We investigated the chemical reactivities of (La0.7Sr0.2Ba0.1)ScO3−δ (LSBS) and LaScO3 powders and Pt foil as functions of reaction temperature, T, oxygen partial pressure, P(O2), and reaction time...