Nominal Formula Research Articles

Analysis of the Sr2GdTi2Nb3O15 ceramic: Investigation into its structural properties and complex impedance spectroscopy

In this study, we successfully synthesized tetragonal tungsten bronze with the nominal formula Sr2GdTi2Nb3O15 and systematically examined of its structure, dielectric, and electrical properties. The material was synthesized through the solid-state reaction technique at a temperature of 1350 °C. The formation of the tetragonal tungsten bronze in the P4/mbm space group was verified via Rietveld refinement using X-ray diffraction data. The electrical characteristics of the ceramic were examined using non-destructive complex impedance spectroscopy (CIS) across a range of frequencies (10–106 Hz) at various temperatures. The real component of impedance (Z') displayed a decrease with rising frequency, suggesting a negative temperature coefficient of resistance (NTCR) for this sample. The Cole-Cole plot of the compound exhibits two semicircles, with the compound's resistance gradually decreasing as the temperature increased. Moreover, the activation energy (Ea) was found to be approximately 0.9 eV, which confirms that oxygen vacancies are responsible for the observed relaxation behavior. Complex modulus analysis confirmed the presence of non-Debye relaxations. These results contribute to a thorough comprehension of the structural and electrical characteristics of Sr2GdTi2Nb3O15, opening avenues for potential applications in diverse electronic devices.

Effect of high pressure synthesis conditions on the formation of high entropy oxides

High entropy materials are often entropy stabilized, meaning that the configurational entropy from multiple elements sharing a single lattice site stabilizes the structure. In this work, we study how high-pressure synthesis conditions can stabilize or destabilize a high entropy oxide (HEO). We study the high-pressure and high-temperature phase equilibria of two well-known families of HEOs: the rock salt structured compound (Mg,Co,Ni,Cu,Zn)O, including some cation substitutions, and the spinel structured compound (Cr,Mn,Fe,Co,Ni)3O4. Syntheses were performed at various temperatures, pressures, and oxygen activity levels, resulting in dramatically different synthesis outcomes. In particular, in the rock salt HEO, we observe the competing tenorite and wurtzite phases and the possible formation of a layered rock salt phase while the spinel HEO is highly susceptible to partial decomposition into a mixture of rock salt and corundum phases. At the highest tested pressures, 15 GPa, we discover the transformation of the spinel HEO into a metastable modified ludwigite-type structure with the nominal formula (Cr,Mn,Fe,Co,Ni)4O5. The relationship between the synthesis conditions and the final reaction product is not straightforward. Nonetheless, we conclude that high-pressure conditions provide an important opportunity to synthesize high entropy phases that cannot be formed any other way.

Simplified Formula for Nominal Force at Critical Welds in the Lower Chord Node of a Novel Bracket-Crane Truss Structure

In the realm of practical engineering, engineers commonly employ rod system models for modeling and analysis, which consequently precludes them from calculating the nominal forces exerted on welds at intricate nodes. This paper addresses the design challenges of the innovative bracket-crane truss structure by proposing a simplified nominal force calculation formula for critical welds of the integrated node. This study commences with the establishment of the frame model and ABAQUS multiscale models, utilizing engineering project drawings and data, followed by a verification of the similarities between the two simulation methods. This similarity of outcomes provides a foundation for directly using the computational results from the frame model in future calculations of the forces at the weld locations. From a mechanical standpoint, this paper derives nominal force calculation formulas for horizontal and vertical welds at critical locations for three node types. Additionally, a formula for calculating nominal shear forces in vertical welds at the end plate of support nodes is introduced. The applicability of these derived formulas is subsequently validated, ensuring their efficacy in accurately capturing relevant forces at critical locations. The presented nominal force calculation formula serves as a valuable tool for optimizing the design and guaranteeing the structural integrity of the integrated node within this distinctive engineering context.

Different Chain Length Tannic Acid Preparations as Coating Agents for Zein Nanoparticles

Proteins that are amphiphilic and have low water solubility can self-assemble into nanoparticles useful in food science, pharmaceutical science, or biotechnology. However, protein nanoparticles exhibit drawbacks such as low stability unless the particles are coated. In the current study, tannic acid is the coating agent for nanoparticles synthesized from the protein zein. Tannic acid is a hydrolyzable tannin comprising a polyol esterified with galloyl residues. The nominal molecular formula of tannic acid (C76H52O46) suggests the material is decagalloyl glucose, obscuring its complex composition as a mixture of galloyl esters of glucose. We prepared hollow zein nanoparticles and coated them with tannic acid preparations that had short or long galloyl ester chains. The % α-helix of zein in nanoparticles is lower than in native zein but there is no effect of coating the particles with tannic acid. Interactions between the tannic acid and the zein slightly perturb the IR spectrum of the protein but there is no effect of galloyl chain length. We confirmed that tannic acid-coated particles have a more negative zeta potential, suggesting greater stability compared to uncoated particles. Coating with longer chain length tannic acid reduces particle diameter and tends to decrease polydispersity but does not change particle digestibility. Coating with shorter galloyl chain length tannic acid tends not to change particle diameter, reduces polydispersity of the particles, and stabilizes particles to enzymatic digestion. Tannic acid is a naturally occurring tunable coating for nanoparticles that can be used to adjust properties such as particle size, polydispersity, and digestibility for specific purposes.

Effect of Mn (as an acceptor) on the structural and electrical properties of non-stoichiometry Sodium Bismuth Titanate/NBT ceramics

The lead free Na0.5Bi0.5TiO3 (NBT) ceramic is proven as a potential piezoelectric candidate; however, non-stoichiometry NBT serves as an outstanding oxide-ion conductor proposed by (M. Li et al., Nature Materials 13 (2014) 31–35). According to this point here we have systematically report the structural and electrical properties of non-stoichiometry Na0.5Bi0.49TiO3/NB0.49T and B-site Mn3+ acceptor-modified NB0.49T system. Therefore, we are trying to prepare the nominal formula of Na0.5Bi0.49Ti1-xMnxO3; NB0.49T ceramic with 0.0≤x ≤ 0.05 by solid state reaction method. The bulk oxide ion conductivity gradually increases with respect to the doping concentration and the maximum value was obtained for x = 0.05 composition. This conductivity maximum is in good consistent with R. A. De Souza's oxygen vacancy diffusivity limit concept for perovskite systems (Advanced Functional Materials, 25 (2015)). On doping of 5mol% of Mn in the Ti-site/B-site NB0.49T system, it was observed that the oxygen-ion conduction inside the grain boundary increased considerably. Grain conductivity of NaBi0.49TiO3 at 500 °C is ∼3.0 ± 0.5 mS cm−1, which is approximately 122 % greater than that pure NBT compositions. Additionally, NB0.9T -exhibited a conductivity value of 4.7 mS/cm at 500 °C, which increases to 9.2 mS/cm on 5 mol% Mn-modification. The observed increase in conductivity was ascribed due to the electrostatic interactions between Mn–Ti or Mn–O bond. Therefore, our current findings on NB0.49T illustrates that present approach should be applicable to modify the system for SOFC application.

New test-based detail categories for fatigue design of crane runway beams

Top-running overhead bridge cranes are frequently supported by welded crane runway beams whose wheel loaded constructional details, such as the welded flange-to-web connections and the continuous double fillet welds to fasten the crane rail, are subject to multiaxial fatigue. The fatigue stressing is composed by normal and shear stresses due to the local wheel load introduction and global bending. As the fatigue stressing exhibits a phase shift of the stress components, it is referred to as nonproportional. The currently applicable detail category of welded flange-to-web connections according to EN 1993-1-9 (2005) is theoretically derived and does not appropriately address the specifics of these connections. A classification of rail welds including a detail-related nominal stress formula is missing. A design proposal for both constructional details is presented that is based on fatigue tests on girders with travelling and stationarily pulsating wheel loads to simulate the nonproportional fatigue stressing. To derive new detail categories from the test results, a fatigue failure hypothesis is formulated modifying Findley’s critical plane approach for the evaluation of welded constructional details with partial penetration and weld root failure on the basis of notch stresses.

Nominal stresses in continuous and intermittent rail welds of crane runway beams

Crane runway beams of hot-rolled I sections are frequently the supporting structures of top-running overhead bridge cranes. In case of light crane service, the crane rails are usually fastened to the top flange of the crane runway beams by fillet welds. A survey among steel construction companies revealed that continuous rail welds as well as intermittent rail welds are commonly used. The rail welds are subject to multiaxial fatigue since they are exposed to normal and shear stresses due to the local wheel load introduction and global bending. Currently, the design standards EN 1993-1-9 (2005) and EN 1993-6 (2007) neither provide an appropriate detail category nor a nominal stress formula for rail welds. The paper focuses on the calculation of the nominal stresses in rail welds as basis of the fatigue action effect within the nominal stress method. It describes the differences in the nominal stresses of continuous and intermittent rail welds because of the contact between rail and top flange that has to be assumed for intermittent rail welds. Based on work samples, the contact conditions of intermittent rail welds are characterized as ‚technical contact‘ (in contrast to ‚ideal contact‘) due to imperfections within the contact surfaces that are described in detail. A Finite Element model is presented that accounts for the ‚technical contact‘ between rail and flange. This model is analyzed in a parametric study to identify the decisive parameters on the nominal stresses in intermittent rail welds.

High-entropy cobalt-free perovskite as a high-performing nanofiber cathode for solid oxide fuel cells

Enhanced oxygen reduction reaction over a high-entropy cobalt-free perovskite with a nominal formula of La1/6Pr1/6Nd1/6Ba1/6Sr1/6Ca1/6FeO3−δ.

Proton conductivity of fluorite based rare earth titanates (LnxTi1-x)4O8-2x (Ln = Yb, Er, Ho, 0.667 ≤ x ≤ 0.765).

Solid solutions of rare earth titanates with high contents of rare earth oxides of up to 50-62% have been synthesized by the co-precipitation method and their structure, microstructure and conductivity in dry and wet air have been studied. Proton conductors have been found for the first time in solid solutions of rare earth titanates with a high content of Ln2O3 (>50%) with a nominal formula composition of (LnxTi1-x)4O8-2x (Ln = Yb, Er, Ho, 0.667 ≤ x ≤ 0.765). Among (LnxTi1-x)4O8-2x (Ln = Yb, Er, Ho, x = 0.684), (HoxTi1-x)4O8-2x (x = 0.684) showed the maximum conductivity in wet air. In this context, four additional compositions (HoxTi1-x)4O8-2x (x = 0.718, 0.734, 0.75, and 0.765) were synthesized in the holmium series. An increase in the holmium content leads to an increase in the proton transfer coefficients; at the same time, a more complex nature of the dependence of the conductivity under dry and wet atmospheres is observed. For the fluorite-like solid solution (HoxTi1-x)4O8-2x (0.701 ≤ x ≤ 0.765), the proton transfer coefficients were found to be ∼0.9 in the range of 200-450 °C. As the temperature continues to rise, the proton conductivity decreases quite sharply and the transfer coefficient becomes as low as 0.3 at 700 °C. The increase in proton conductivity in the Yb-Er-Ho series is associated with an increase in the hydrophilic properties of rare earth cations. In the (HoxTi1-x)4O8-2x (x = 0.667 ≤ x ≤ 0.765) series, the conductivity in wet air was ∼1 × 10-6 S cm-1 at 450 °C for most compositions. The conductivity of ceramics with x = 0.701 and 0.75 is about 2 times higher, which may be due to the optimal size of pyrochlore nanodomains in the fluorite matrix for x = 0.701 and the formation of pure fluorite for x = 0.75, respectively.

Synthesis, characterization, and first-principles analysis of Mo2NiB2-type high-entropy boride ceramic

A Mo2NiB2-type high-entropy boride ceramic with the nominal formula of (Mo0.5W0.5)2(Fe0.3Co0.35Ni0.35)B2 (abbreviated as X3B2) was synthesized by vacuum sintering. The phase structure, crystalline construction, bonding, and hardness properties were clarified in detail by first-principles calculations and experiment. The results show that the as-synthesized sample exhibits single phase and satisfied compositional homogeneity. Moreover, it can be obtained that both Mo–B bonds and W–B bonds in X3B2 exhibit the covalent characteristics, while the binding of Mo–B is stronger than the other. Initial property assessments show that the Vickers hardness of X3B2 is generally more than 20% higher than the reported Mo2NiB2. These results suggest an idea to achieve high hard and high-performance materials via exploring high-entropy ternary-boride ceramic.

Anti-occupation defect dipole and gradient interface induced excellent giant permittivity in Sr0.95Bi0.05TiO3 ceramics

In this research, non-stoichiometric Bi doped SrTiO3 (ST) ceramics with nominal chemical formula of BixSr1-xTiO3 (x = 0, 0.01, 0.03, 0.05, 0.07) were produced through a conventional solid-state reaction route. A giant permittivity (ε) ∼30000 and low dielectric loss (tanδ) ∼0.03 were obtained in Bi0.05Sr0.95TiO3 ceramic. The temperature-ε and frequency-ε plots were conducted to investigate dielectric properties of the ceramics. The results of dielectric property plots revealed that the Bi0.05Sr0.95TiO3 ceramic has excellent dielectric stability within the range of 103–106 Hz and 30–250 °C. The fine scan XRD analysis, X-ray photoelectron spectrometer (XPS) and first principles calculation results showed that giant permittivity property of the Bi0.05Sr0.95TiO3 ceramic maybe attributed to the Bi‘Ti−VO∙∙−Bi‘Ti defect dipoles caused by Bi anti-occupation doping. And the gradient interface formed by Bi excessive doping also contributed to the giant permittivity. This study offers a new approach for achieving a giant permittivity with low dielectric loss in ST ceramic capacitors.

Self‐Configured Composites of Ruddlesden‐Popper Perovskite and Pr6O11 as Efficient and Durable Air Electrodes for Reversible Protonic Ceramic Electrochemical Cells

AbstractA breakthrough in the development of air electrodes is critical to minimizing the performance deterioration of reversible protonic ceramic electrochemical cells (R‐PCECs), which have demonstrated the potential to be the most promising electrochemical device for energy storage and conversion. Here, a Co‐doped Ruddlesden‐Popper (RP) perovskite with a nominal formula of Pr2Ni0.6Co0.4O4‐δ is reported, which is self‐configured into a composite of Pr4Ni1.8Co1.2O10‐δ (PNCO, 89.57 wt.%) and Pr6O11 (10.43 wt.%), suggested by the X‐ray diffraction refinement. The composite electrodes exhibit improved electrochemical activity with an area‐specific resistance of 0.33 Ω cm2 at 600 °C after being treated with wet air, due primarily to the raised surface exchange, bulk diffusion capabilities, and the increasing amount of Pr6O11 with catalytic activity. The R‐PCECs with the composite electrodes achieve a maximum power density of 1.32 W cm−2 and a current density of 3.09 A cm−2 at 1.3 V with acceptable Faradaic efficiencies at 650 °C. Furthermore, the composite electrodes show benign operational durability in fuel cell mode (‐0.5 A cm−2 for 167 h) and electrolysis mode (+0.5 A cm−2 for 176 h), and promising cycling stability (+/‐0.5 A cm−2) of 124 h at an interval of 2 h.

Synthesis of ZnFe2O4 spinel nanoparticles at varying pH values and application in anode material for lithium-ion battery

Spinel materials have attracted increasing attention as anode materials for lithium-ion batteries (LIBs) owing to their unique structures. ZnFe2O4 spinel was synthesized by a co-precipitation method at different pH values — pH 11, pH 12, and pH 13 — followed by annealing in air at 750 °C for 3 h. The pH of the medium significantly influences the properties of ZnFe2O4. At pH 11, ZnFe2O4 particles of sizes 25–70 nm were covered by amorphous layers with thicknesses of approximately 2 nm, whereas higher degrees of crystallinity and larger particle sizes were obtained at higher pH values (12 and 13). Additionally, at pH 12, the Zn:Fe molar ratio in the prepared sample was 1:1.3, which deviated significantly from the nominal formula (1:2). Possibly, owing to the presence of amorphous layers that allow an isotropic volume change during the lithiation/delithiation steps, ZnFe2O4 prepared at pH 11 exhibited the best performance when employed as an anode material in LIBs. Namely, its reversible specific capacity at the 1st and the 160th cycles at 0.1 A g−1 were 0.69 Ah g−1 and 0.72 Ah g−1, respectively. Although ZnFe2O4 prepared at pH 12 gave an initial reversible specific capacity up to 0.89 Ah g−1, its capacity retention after 160 cycles was only 20%. Therefore, adjusting the pH of the coprecipitation step can improve the final lithium storage performance by controlling the degree of crystallinity, particle size, and chemical composition of the anode material ZnFe2O4.

In Situ Generation of Pseudorutile Oxide as the Cathode for Direct Electrolysis of CO2.

The conversion of CO2 into CO in high-temperature solid oxide electrolysis cells (SOECs) is an attractive route for the CO2 utilization using the intermittent renewables. The low-cost and highly catalytic cathode is important for the direct electrolysis of pure CO2. In this study, non-perovskite Fe0.5Mg0.25+0.5xTi0.25-0.5xNb1-xMoxO4 oxides (denoted as Mo-x when x is equal to 0, 0.1, and 0.2) are evaluated as the cathode of an SOEC for the direct electrolysis of CO2. Mo6+ doping converted the wolframite Mo-0 into an α-PbO2-type with cation disordering, while further doping to Mo-0.2 showed a wolframite with cation ordering again. The SOEC with Mo-0.2 as the cathode exhibits the best electrochemical performance for the direct electrolysis of CO2 as a large portion of the oxide converted into oxygen-deficient pseudorutile-type oxide with a nominal formula of M5O9 (M = cation). The pseudorutile, a crystallographic shear phase of rutile, can be obtained after 60 h of direct electrolysis in CO2 at a 1.3 V bias rather than a reduction under 5% H2. The SOEC with Mo-0.2 as the cathode imparted a stable current density of 0.45 A cm-2, which could be related to the production of pseudorutile decorated with nanoparticles of MoO2. These results show that molybdenum doping is an effective strategy for developing oxygen-deficient rutile (pseudorutile) for the electrolysis of CO2.

Perovskite-Type Nd1-XBaxCo0.8Fe0.2O3-δ (0 ≤ x ≤ 0.7) Cathodes for Intermediate Temperature Solid Oxide Fuel Cells

Perovskite-type metal oxides with a nominal chemical formula of Nd1-xBaxCo0.8Fe0.2O3-δ (NBCF) (0 ≤ x ≤ 0.7)were prepared by solid-state synthesis method at 1300 °C in air. Powder X-ray diffraction showed that the x =0.25 member is a single-phase perovskite-type Nd0.75Ba0.25Co0.8Fe0.2O3-δ in the Pnma space group and all othermembers were found to be multiphase. All the investigated NBCF compositions show minor reactivity with theSr and Mg-co-doped lanthanum gallate (LSGM) when sintered with 30 wt.% LSGM at 1050 °C but maintaintheir perovskite-type structure. 4-probe DC chronopotentiometry measurements were performed on the sinteredsample pellets. The x = 0.4 member reaches a maximum conductivity of 1068 S/cm at 300 °C in air. Among thesamples studied, the x = 0.55 member exhibits the lowest area specific polarization resistance (ASR) of 0.026 Ωcm2 at 750 °C in air.

Figures of merit of PLZT ferroelectric ceramics for practical applications

Structural, microstructural and pyroelectric properties were investigated in PZT-based ferroelectric ceramics for a composition close to the morphotropic phase boundary (Zr/Ti = 53/47), as a function of the lanthanum content. The samples were prepared via the conventional solid-state reaction sintering method. Three compositions were synthetized and studied following the PbZr0.53Ti0.47O3 + x mole% La nominal formula, where x = 0.0, 2.5 and 5.0. The structural characterization confirmed the presence of both tetragonal and rhombohedral phases for all the studied compositions, showing a decrease in the tetragonality factor (c/a) with the increase of the lanthanum concentration. The observed decrease in the stability of the ferroelectric phase (in favor of the paraelectric one) have been discussed in light of the solubility of the doping cation into the studied PZT perovskite structure. Microstructural properties revealed low pores concentration micrographs, showing homogeneous microstructures and uniform grain-sizes. The pyroelectric response of the as-prepared PLZT samples was also investigated in a wide temperature interval. The lower lanthanum content composition exhibited the best properties, characterized by a high pyroelectric coefficient and enhanced figures of merit. These characteristics make such a composition a promising material for practical applications.

On the role of copper as a sintering aid in proton conducting Gd-doped barium cerate (BCGO)

Several orthorhombic perovskite products with nominal chemical formula BaCe0.85Gd0.15O3–δ (BCGO), doped with variable amounts (0–5 mol%) of CuO and characterized by high total ionic conductivities, were synthesized by a sol-gel method followed by a calcination step at 1200 °C to induce the formation of a perovskite single phase. The products were characterized by X-ray Diffraction (XRD), Rietveld refinement, Scanning Electron Microscopy (SEM), Raman spectroscopy and Electrochemical Impedance Spectroscopy analysis (EIS). The powders were sintered into highly dense bodies (greater than 99 % for the best sample) through a relatively mild sintering process, i.e. 1350 °C for 6 h. The positive effect of copper as a sintering aid was revealed when a threshold content value (around 2 mol%) was e. Indeed, beyond such a limit, by calcination at 1200 °C, a secondary phase, a mixed oxide of Cu, Ba and Gd (very likely with chemical formula GdBa4Cu3O9.18) appears in the precursor powders strongly enhancing the densification process, reasonably via partial liquid-phase sintering. Finally, remarkable grain growth also occurred, enhancing the overall conductivity of BCGO due to the positive effect of the reduction of grain boundary dimensions.

Perovskite-Type Nd1-XBaxCo0.8Fe0.2O3-δ (0 ≤ x ≤ 0.7) Cathodes for Intermediate Temperature Solid Oxide Fuel Cells

Perovskite-type metal oxides with a nominal chemical formula of Nd1-xBaxCo0.8Fe0.2O3-δ (NBCF) (0 ≤ x ≤ 0.7) were prepared by solid-state synthesis method at 1300 °C in air. All members were found to be multiphase. 4-probe DC chronopotentiometry measurements were performed on the sintered sample pellets. The x = 0.4 member reaches a maximum conductivity of 1068 S/cm at 300 °C in air. Among the samples studied, the x = 0.55 member exhibits the lowest area specific polarization resistance (ASR) of 0.026 Ω cm2 for the oxygen reduction reaction (ORR) at 750 °C in air.

Loveringite from the Khamal Layered Mafic Intrusion: The First Occurrence in the Arabian Shield, Northwest Saudi Arabia

Loveringite, a rare member of the crichtonite group with nominal formula (Ca,Ce)(Ti,Fe,Cr,Mg)21O38, was found in the Khamal layered mafic intrusion, the first known locality for this mineral in the Arabian Shield. The Khamal intrusion, a large post-collisional mafic complex, is lithologically zoned, bottom to top, from olivine gabbro through gabbronorite, hornblende gabbro, anorthosite, and diorite to quartz diorite. Loveringite is found near the base of the complex, as an intercumulus phase in olivine gabbro. Most loveringite grains are homogeneous, although a few grains are zoned from cores rich in TiO2, Al2O3, Cr2O3, and CaO towards rims rich in FeO*, ZrO2, V2O3, Y2O3, and rare earth elements (REE). Petrographic relations indicate that loveringite formed after crystallization of cumulus olivine, pyroxenes, and plagioclase. Anhedral and corroded crystals of loveringite are surrounded by reaction rims of Mn-bearing ilmenite and baddeleyite, suggesting that the residual liquid evolved into and subsequently out of the stability field of loveringite. The budget of incompatible elements (Zr, Hf, REE, U, and Th) hosted in loveringite is anomalous for a primitive mafic liquid. Saturation in loveringite is likely the result of early contamination of the primary melt by anatexis of country rock, followed by isolation of evolving liquid in intercumulus space that restricted communication with the overlying magma chamber. The zoned crystals likely reflect diffusive equilibration between residual loveringite grains and their reaction rims of ilmenite.

Preparation and characterization of La1.75Y0.25Mo2-xAlxO9-δ as solid electrolyte for intermediate temperatures SOFC

Yttrium and aluminium co-substitutions on lanthanum molybdate ceramics with the nominal formula La1.75Y0.25Mo2-xAlxO9-?? (LYMA, x = 0, 0.1, 0.2, 0.3 and 0.4) were synthesized by citric acid-nitrate combustion method and used for preparation of solid electrolyte for intermediate-temperature solid oxide fuel cells (ITSOFCs). Phase composition, structure, conductivity and electrical properties of LYMA have been investigated as a function of aluminium content by X-ray diffraction, scanning electron microscopy and electrochemical impedance spectroscopy, respectively. Experimental results showed that the substitution of La and Mo with appropriate amounts of Y and Al can effectively stabilize the ?-form of La2Mo2O9 at room temperature and inhibit its phase transition to ?-form. The LYMA synthesized by combustion method exhibited a better sinterability where relative density of the samples sintered at 950?C for 4 h was higher than 95%TD. The performance of the LYMA electrolyte was found to be related to Al-content. The La1.75Y0.25Mo1.8Al0.2O8.7 exhibited high oxide ion conductivity (?= 42mS/cm at 800?C) and low electrical activation energy (Ea = 1.18 eV). These preliminary results indicate that the LYMA is a promising electrolyte for IT-SOFCs.