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A significant structural modification and enhancement of the electrical and magnetic properties with dilute substitution of Zr (≤1mol.%) in the Bi0.8La0.2Fe1-xZrxO3 system has been reported. A mixture of rhombohedral and orthorhombic phases was detected in these conventionally sintered ceramics. Transition from a leaky state to an insulating state was observed upon Zr substitution. This is the first time that a drop in the electrical conductivity as large as 6 orders of magnitude for doping as small as 0.25mol. % in bismuth ferrite systems has been reported. An investigation on the nature of this abrupt transition revealed the dominant role of defects. A proper consideration of possible defect reactions taking place during and after sintering satisfactorily accounts for the observed modulation in the electrical properties. Both AC and DC measurements indicate that, before Zr substitution, ptype hopping conduction prevails with an activation energy as low as ~0.57 eV, whereas the Zr substitution makes oxide ion migration the central mechanism for conduction with the activation energy of ~0.96-1.08 eV. In contrast to that, the magnetic properties of the compounds experience a more subtle effect; a gradual modification of saturation magnetization and coercivity with Zr substitution is observed. Curve fitting of the magnetic hysteresis loops not only allowed extraction of three separate contributions from the magnetic response but also helped to explain the effects of Zr on the magnetic properties. Modifications of structural characteristics and magnetic anisotropy of the samples are believed to be the primary driving force behind the improvement in the magnetic properties. [ABSTRACT FROM AUTHOR]

The systematic study on structural properties of Ba-substituted La0.9Sr0.1Al0.9Mg0.1O3-δ and its correlation with conductivity was carried out. X-ray diffraction patterns indicated that the system formed a single phase composition up to 3% of Ba double substitution at the La-site. Energy dispersive X-ray spectroscopy and XPS results confirmed elemental compositions and revealed the maximum deficiency in oxygen for the 3% Ba-substituted sample. Dense grain formation is observed in SEM images, complementing higher density of these samples (>93%). Electrical conductivity was found to be in correlation with a new structural parameter of the critical triangle of (La/Sr/Ba)- Al/Mg-(La/Sr/Ba). The value of conductivity increased by an order of 2 in a substituted sample as compared to pure LaAlO3. The activation energy can be correlated with the area of the critical triangle of (La/Sr/Ba)-Al/Mg-(La/Sr/Ba). The migration path for ionic conduction of the oxygen ion was mapped out using the correlation of bulk conductivity with the A-A-B angle (β) and dc conductivity with the A-B-A angle (α). [ABSTRACT FROM AUTHOR]

In this study, polymeric films based on chitosan (CS) doped with Lanthanum oxide nanoparticles at different weight percentages (5, 10, 15, and 20% La2O3/CS) were prepared using the simple solution cast transformation. The dielectric constant increases with increasing the La2O3 content, and this could be attributed to the induced defects, as a result more dipoles are produced in the polymer matrix. Also, the values of Z′ and Z″ increase with La contents. On other hand, we noticed that the plot of the normalized-imaginary electric modulus versus the frequency shows a clear peak at high frequency for all samples. This peak is associated with ionic conduction. The AC conductivity increased by increasing the La2O3 content. Furthermore, AC conductivity increases with frequency because the absorbed energy from the electric field can increase the number of charge carriers that are participating in the electric conduction. Moreover, the values of the universal exponents were larger than the unity and increase with increasing temperatures which means that the conduction process may be pertinent to reorientational (or localized) mechanism. [ABSTRACT FROM AUTHOR]

In this work, we have studied electrical conductivity and dielectric properties of polycrystalline La2_xYxMo2O9 (0.05 = x = 0.3) compounds in the temperature range from 358 K to 1088 K and the frequency range from 10 Hz to 3 GHz. The bulk and grain boundary contributions to the overall conductivity of these compounds show Arrhenius type behavior at low temperatures. The random free-energy barrier model has been used to analyze the frequency dependence of the conductivity. The charge carrier relaxation time and its activation energy have been determined from the analysis of the conductivity spectra using this model. The results obtained from the random free-energy barrier model satisfy Barton-Nakajima-Namikawa relation. The conduction mechanism has been also predicted using random free-energy barrier model and the scaling formalism. We have observed that the dielectric relaxation peaks arise from the diffusion of oxygen ions via vacancies. [ABSTRACT FROM AUTHOR]

The electrical conduction mechanism in La3Ta0.5Ga5.5O14 (LTG) was studied from the standpoint of defect formation during growth caused by the nonstoichiometry of the crystal. Since the stoichiometric composition of LTG does not coincide with the congruent composition, single crystals grown from the stoichiometric melt under an atmosphere of O2/Ar in the oxygen partial pressure range from 0.005 to 1 atm was Ta-poor. Ta vacancies were formed during the growth, and their population was predominated by the growth-pO2. With increasing temperature up to 600 °C, the Ta vacancies were ionized to yield holes, and thus the electrical conductivity of the LTG crystal varied with temperature and growth-pO2. In contrast, Ga vacancies as a carrier source would form by Ga evaporation during growth under pO2 below 0.005 atm. The growth-pO2 dependence of the electrical conductivity was opposite to the case for Ta vacancies. For the case of sintered LTG with the exact stoichiometric composition, impurity defects dominated electrical conduction below 600 °C, where the impurity concentration was higher than the cation vacancies arising from the nonstoichiometry of the sintered LTG. Thus, electrical conductivity was almost independent of the sintering atmosphere of pO2. Above 700 °C, the dominant carrier in both single crystal and sintered LTG was ions related to oxygen defects formed by the anion Frenkel reaction. [ABSTRACT FROM AUTHOR]

The electrical conduction mechanism in La3Ta0.5Ga5.5O14 (LTG) was studied from the standpoint of defect formation during growth caused by the nonstoichiometry of the crystal. Since the stoichiometric composition of LTG does not coincide with the congruent composition, single crystals grown from the stoichiometric melt under an atmosphere of O2/Ar in the oxygen partial pressure range from 0.005 to 1 atm was Ta-poor. Ta vacancies were formed during the growth, and their population was predominated by the growth-pO2. With increasing temperature up to 600 °C, the Ta vacancies were ionized to yield holes, and thus the electrical conductivity of the LTG crystal varied with temperature and growth-pO2. In contrast, Ga vacancies as a carrier source would form by Ga evaporation during growth under pO2 below 0.005 atm. The growth-pO2 dependence of the electrical conductivity was opposite to the case for Ta vacancies. For the case of sintered LTG with the exact stoichiometric composition, impurity defects dominated electrical conduction below 600 °C, where the impurity concentration was higher than the cation vacancies arising from the nonstoichiometry of the sintered LTG. Thus, electrical conductivity was almost independent of the sintering atmosphere of pO2. Above 700 °C, the dominant carrier in both single crystal and sintered LTG was ions related to oxygen defects formed by the anion Frenkel reaction. [ABSTRACT FROM AUTHOR]

Thermoelectric properties of layered oxyselenides La[sub 1-x]Sr[sub x]CuOSe (x=0.00 to 0.20) were investigated to evaluate the potential as thermoelectric material. Temperature dependence of the electrical conductivity and Seebeck coefficient measured in a temperature range of 373 to 673 K indicated that nondoped LaCuOSe was a p-type degenerate semiconductor due to Cu vacancies, while Sr-doped materials with x=0.05 to 0.20 were p-type metals. The electrical conductivity increased and Seebeck coefficient decreased with increasing Sr concentration up to x=0.10 in La[sub 1-x]Sr[sub x]CuOSe, suggesting that the effective hole carriers increase with increasing Sr content up to x=0.10. Thermoelectric power factors were drastically enhanced by the Sr doping, and the value reached 1.0-1.4×10[sup -4] W m[sup -1] K[sup -2] for La[sub 0.95]Sr[sub 0.05]CuOSe. Thermal conductivities measured for the materials with x=0.00 and 0.05 were 2.1 W m-1 K-1 and 2.3 W m-1 K-1 at room temperature, respectively. These results lead to an estimation of Z value of 4.4×10[sup -5] K[sup -1] for La[sub 0.95]Sr[sub 0.05]CuOSe. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Effect of particles size on the behavior of magnetoimpedance, magnetodielectric and detailed electrical properties of structural characterized LaFeO3 nanoparticles prepared through chemical 'pyrophoric reaction' technique having particles size of ~ 21, 43 and 51 nm have investigated. Dielectric constant of these nanoparticles gives the evidence of space charge polarization in the sample at lower frequency regime. Maximum magnetodielectric effect is obtained to ~ 61% at room temperature for particle size of ~ 21 nm, which may be due to the large surface to volume ratio of this nanoparticles compared to other particles size attributing the enhancement of space charge polarization. The maximum value of magnetoimpedance is found to ~ 92% for ~ 21 nm nanoparticle at room temperature. Magnetic field and frequency dependence room temperature magnetoimpedance are decreased with particles size of the nanoparticles. This behaviour has been explained through the light of classical electrodynamics, which reveals that this effect is depending on the magnetic field and ac signal frequency. Impedance spectroscopy is employed to study the electrical transport properties of the samples considering an equivalent circuit model for the effect of nanometric grain size. The electrical relaxation process of these materials is temperature dependent. Furthermore, ac conductivity curves follow the Jonscher's power law for electrical conduction process of the system through polaronic hopping. [ABSTRACT FROM AUTHOR]

Abstract Single-phase Ruddlesden popper of La 2-x Sr x CoO 4 nanopowders with x = 0.7, 0.9, 1.1 and 1.3, were successfully synthesized by a modified sol-gel method. Structural stability and morphology of the prepared samples were examined using HT-XRD analysis, FE-SEM and SEM techniques. HT-XRD analysis of the samples, in the range of room temperature to 850 °C, revealed that the structure of all samples was tetragonal. The electrical conductivity measurements, in the range of room temperature to 850 °C, indicated that by increasing the temperature the electrical conductivity mechanism inverts from variable range hopping to the nearest-neighbor hopping of small polarons. In addition, it was found that by increasing Sr concentration the structure of the sintered samples becomes more stable. The electrochemical characterization was carried out using the impedance spectroscopy (EIS) measurements on symmetrical cells at three different temperatures, 650 °C, 750 °C and 850 °C. The area specific polarization resistance (ASR) of La 2-x Sr x CoO 4 -CGO-La 2-x Sr x CoO 4 symmetrical cell, in oxygen flow, was obtained about 1.07, 0.35, 0.33 and 0.43 Ωcm2 at 850 °C for the samples with x = 0.7, 0.9, 1.1 and x = 1.3, respectively. According to our EIS results, the main rate-limiting step for La 2-x Sr x CoO 4 cathode performance is the dissociation process of oxygen at the surface of cathode at 650 °C and the charge transfer limiting in the cathode/electrolyte at 750 °C and 850 °C. Our results showed that the samples with Sr contents of x = 0.9 and x = 1.1 can be the promising cathodes for IT-SOFC applications. [ABSTRACT FROM AUTHOR]

La0.6Ca0.3Ag0.1MnO3 system has been synthesized using the cheap solid-solid process. Structural analysis indicates that the sample exhibits a single phase of intragranular. Electrical and dielectric data, over a wide temperature range and frequencies have been recorded with impedance spectroscopy. We visualize the conductivity, whose activation energy is low, as a successive hopping of electrons as polaron does. Further, the conductivity is governed by the small polaron hopping model at higher temperature region while it fits well with the variable range hopping model at a lower temperature range. Dielectric data has been represented in different alternative complex formalisms, from which complementary information has been extracted. The complex impedance diagram suggests the contribution of only two active microstructures, ruling out the electrode polarization effect. We adopt the spectrum of the imaginary component of the electric modulus M″ to distinguish long range hopping from short range hopping. The relative permittivity spectrum permits to identify the possibility of the existence of electric polarizations. Further, it reveals colossal static dielectric constant, which makes it suitable for multitude potential applications in electronic industrial fields. [ABSTRACT FROM AUTHOR]

Fundamental aspects of the phase formation and morphology of films of the proton-conducting solid electrolyte La0.95Sr0.05ScO3-δ, produced by wet deposition from inorganic salts on a porous cathode substrate La0.6Sr0.4MnO3-δ. The conditions in which gas-tight films are deposited onto substrates with porosity of up to 25% were determined. The electrical conductivity of La0.95Sr0.05ScO3-δ films was examined in relation to temperature and gas-phase composition (рН2О, рО2). The effect of the architecture of the electrolyte membrane on its transport properties was analyzed. The results of the study are of fundamental importance for development of proton-ceramic fuel cells with a supporting electrode. [ABSTRACT FROM AUTHOR]

Mo-doped La 2 Ce 2 O 7 with varied concentrations are prepared by the traditional citrate-nitrate combustion method. The effects of the phase structure of Mo-doped La 2 Ce 2 O 7 are investigated by X-ray diffraction, scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and conductivity measurements. X-ray diffraction patterns reveal that all La 2-x Mo x Ce 2 O 7+δ samples have a cubic structure. Neverly, hole can be found on the surface of the samples from scanning electron microscopy. Raman spectra show that the different vibrating structures of pellets can be changed by introducing Mo into La 2 Ce 2 O 7 . Detailed X-ray photoelectron spectroscopy studies on the oxidation states of La 2 Ce 2 O 7 and La 1.85 Mo 0.15 Ce 2 O 7+δ indicate ratios of O C to O T (O T = O C + O L ) are between 32.21% and 46.24%. The conduction behaviour of Mo doped La 2 Ce 2 O 7 electrolyte is seriously researched under air and 5%H 2 -95%Ar conditions at 350–700 °C, and the highest conductivity of 7.36 × 10 −3 and 1.65 × 10 −2 Scm −1 , respectively, are obtained with La 1.85 Mo 0.15 Ce 2 O 7+δ pellets at 700 °C. The highest power density of single cells with the La 1.85 Mo 0.15 Ce 2 O 7+δ electrolyte is approximately 0.643 Wcm −2 at 700 °C, suggesting that Mo-doped La 2 Ce 2 O 7 can be used to substantially improve the electrochemical performance of low-temperature solid oxide fuel cells. [ABSTRACT FROM AUTHOR]

Ferrite perovskites have exhibited promising p-type conductivity and oxygen evolution reaction (OER) activity. In this work, we investigate heteroepitaxial p-n junctions formed by La0.88Sr0.12FeO3 and n-SrTiO3(001). Sr substitution for La in LaFeO3 is shown to be effective for introducing p-type conductivity, lowering the optical bandgap, and enhancing electrocatalytic OER. A staggered, type-II band alignment with a large built-in potential within the LSFO forms due to the polar interface. This electronic structure facilitates charge transfer across the p-n junction and accounts for the strongly thickness-dependent extent of OER we observe. [ABSTRACT FROM AUTHOR]

We report the thermoelectric (TE) properties of (1-x)LaCoO 3 .xLa 0.7 Sr 0.3 MnO 3 (0 < x < 0.50) composite in a temperature range 320–800  K . Addition of La 0.7 Sr 0.3 MnO 3 to LaCoO 3 in small amount (5 weight %) improves the overall Seebeck coefficient ( α ) at higher temperatures. The electrical conductivity however decreases due to a decrease in carrier concentration of the composite. The decrease in electrical conductivity of the composite at high temperature may be attributed to the insulating nature of the LSMO above room temperature. Thermal conductivity ( κ ) of all the samples increases with an increase in the temperature, but decreases with increasing LSMO content. We also report the local variation of Seebeck coefficient across the composite samples measured using a precision Seebeck measurement system. A maximum value of 0.09 for the figure of merit ( ZT ) is obtained for 0.95LaCoO 3 .0.05La 0.7 Sr 0.3 MnO 3 at 620 K which is significantly higher than the ZT of either of LaCoO 3 or La 0.7 Sr 0.3 MnO 3 at 620 K. This suggests the potential for enhancement of operating temperatures of hitherto well known low temperature thermoelectric materials through suitable compositing approach. [ABSTRACT FROM AUTHOR]

Li 3/8 Sr 7/16-3x/2 La x Zr 1/4 Nb 3/4 O 3 (x = 0, 0.05, 0.10, 0.15, 0.20) were synthesized using the conventional solid-state reaction method. In order to increase the vacancy concentration, La 3+ was doped on the Sr 2+ site. Crystal structures of doped samples were characterized by X-ray diffraction. Except, perovskite-type Li 3/8 Sr 7/16-3x/2 La x Zr 1/4 Nb 3/4 O 3 (x = 0, 0.05, 0.10, 0.15) samples were fabricated by heat treatment at 1250 °C, 1275 °C, 1275 °C and 1275 °C, respectively, for 15 h. Lattice sizes decreased with the increase of doping amounts because of the smaller ion radius of La 3+ compared to that of Sr 2+ . Ionic conductivities of the samples were measured by AC impedance spectroscopy. The results showed that the ionic conductivity increases at first and then decreases with raising doping amounts and sintering temperatures. So the optimized composition Li 3/8 Sr 7/16-3x/2 La x Zr 1/4 Nb 3/4 O 3 (x = 0.05) sintered at 1275 °C was selected with the highest total conductivity of 3.33 × 10 −5 S cm −1 at 30 °C and an activation energy of 0.27 eV. Additionally, potentiostatic polarization test was used to evaluate the electronic conductivity. The optimal composition Li 3/8 Sr 7/16-3x/2 La x Zr 1/4 Nb 3/4 O 3 (x = 0.05) as a possible Li-ion conducting solid electrolyte has an electronic conductivity of only 8.39 × 10 −9 S cm −1 . [ABSTRACT FROM AUTHOR]

Transparent conducting oxides (TCOs) are a unique series of materials combining electrical conductivity with optical transparency. Most of the commercially available TCOs are of the n-type. The performance of p-type TCOs, however, is far behind their n-type TCO counterparts primarily due to the doping bottleneck and low hole mobility. Herein, a Mott-Hubbard insulator of LaVO3 is proposed as the starting point for exploring p-type TCOs. Substitution of La3+ by Sr2+ can introduce high hole carrier concentration at the top of the valence band to overcome the doping bottleneck. Combining a modest carrier mobility with weak absorption in the visible region, La1-xSrxVO3 compounds can serve as new p-type TCOs and exhibit good balance of the tradeoffs between electrical conductivity and optical transparency. It is demonstrated that La2/3Sr1/3VO3 thin films exhibit a high conductivity of 742.3-872.3 S cm-1 at room temperature and a high transmission of 53.9-70.1% in the visible region, which leads to the highest figure of merit among p-type TCOs so far. [ABSTRACT FROM AUTHOR]

We report room temperature tunability of structural, dielectric, optical and magnetic properties by Ca/Mn co-substitution in LaFeO 3 . XRD reveals single phase formation. The co-substitution driven lattice strains are noticed in terms of changes in Fe/Mn–O–Fe/Mn bond angle and bond lengths. The XRD results on structural parameters are corroborated with Fourier transform infrared spectrum. The change in magnetic response appear to be well correlated with structural distortion in terms of Fe/Mn–O–Fe/Mn bond angle deviation and possible indirect exchange interactions between Fe and Mn via intervening oxide ion. Substantial improvement in dielectric response (ε r ∼ 10 3 ) at RT was noted on co-substitution in LaFeO 3 . The dielectric spectrum exhibits non Debye type behavior and the same is confirmed in modulus spectrum. Modulus spectrum confirmed the presence of concentration dependent relaxation. Dielectric and optical property seems consistent with electrical conductivity changes as a function of concentration. Evidence of thermally activated Arrhenius type conduction is noticed. [ABSTRACT FROM AUTHOR]

Systematic characterization of lanthanum tungstate (LWO) with a high La/W ratio was conducted to evaluate its suitability as a proton-conducting solid electrolyte for fuel cells operating at intermediate temperature. In this study, the crystal structure, ionic and electronic transport properties of LWO with a high La/W ratio (La/W = 6.7: LWO67), which had high proton conductivity, were investigated. Rietveld analysis using synchrotron powder X-ray diffraction confirmed the single-phase formation of LWO67 having a cubic crystal structure with the Fm 3 ¯ m space group. The coefficient of thermal expansion of LWO67 was also evaluated from Rietveld analysis at high temperatures. Thermogravimetric analysis indicated a good chemical stability of LWO67 under wet CO 2 conditions. The observed electrical properties indicated that the proton conductivity was dominant under wet conditions below 873 K. The dependence of the electrical conductivity on oxygen partial pressure suggested that the electron and hole conductivities were suppressed sufficiently below 973 K. Based on the observed transport properties, the superiority of LWO67 applied to a proton-conducting solid electrolyte fuel cells (p-ITFCs) was also discussed. The optimized electrolyte thickness of LWO67 was several tens of micrometers, which is more suitable than perovskite-type proton conductors such as BaZrO 3 and BaCeO 3 for electrode-supported fuel cells, when they are compared in terms of power generation efficiency. [ABSTRACT FROM AUTHOR]

Proton concentration of La 1.9 Ca 0.1 Zr 2 O 7 − α in H 2 O–O 2 atmospheres has been measured by means of the method of high temperature thermogravimetry. The oxygen diffusion coefficient and the oxygen surface exchange coefficient have been measured for La 1.9 Ca 0.1 Zr 2 O 7 − α over the temperature range of 600–900 °C using the oxygen isotope exchange method with gas phase equilibration. pO 2 -dependencies of the electrical conductivity have been determined in the temperature range 500–800 °C and oxygen partial pressure range of 10 − 20 < pO 2 < 0.21 atm in atmosphere saturated with water vapour at 25 °С ( p Н 2 О = 0.03 atm). Ionic conductivity has been divided into protonic and oxygen-ionic components. The influence of oxygen defect structure on the water uptake, oxygen diffusivity and electrical conductivity of La 1.9 Ca 0.1 Zr 2 O 7 − α has been discussed. [ABSTRACT FROM AUTHOR]

Sc-substituted La 0.6 Sr 0.4 FeO 3-δ (LSFSc) has been synthesized for utilization as an integrated ceramic interconnector of tubular-solid oxide cells (SOCs). Redox stability and electric conductivity of LSFSc were improved by optimizing the scandium (Sc) doping concentration, the pH of the synthetic solutions and the calcination temperature of the organic precursors. The crystalline phases of LSFSc were stable when the pH of the synthetic solution was below 2 and the calcination temperature was over 1200 °C. As the Sc concentration increased, redox stability was improved while the electrical conductivity decreased. To consider the trade-off relationship between electrical conductivity and phase stability, La 0.6 Sr 0.4 Fe 0.9 Sc 0.1 O 3-δ can be considered as one of the stable compositions for an integrated ceramic interconnector of tubular-SOCs. [ABSTRACT FROM AUTHOR]

Increasing electrical conductivity in oxides, which are inherently insulators, can be a potential route in developing oxide-based thermoelectric power generators with higher energy conversion efficiency. In the present work, environmentally friendly non-toxic double perovskite LaxSr2−xTiMoO6 (LSTM) ceramics were synthesized using a solid-state reaction route by optimizing the sintering temperature and atmosphere for high temperature thermoelectric applications. Rietveld refinement of XRD data confirmed a single-phase solid solution with a cubic structure in these double perovskites with the space-group Pm3̅m. SEM studies showed a highly dense microstructure in these ceramics. High electrical conductivity on the order of 105 S m−1 and large carrier concentration (∼1022 cm−3) were obtained in these materials. The temperature-dependent electrical conductivity measurement showed that the LSTM ceramics exhibit a semiconductor to metal transition. Thermopower (S) measurements demonstrated the conductivity switching from a p-type to n-type behavior at higher temperature. A temperature dependent Seebeck coefficient was further explained using a model for coexistence of both types of charge carriers in these oxides. A conductivity mechanism of these double perovskites was found to be governed by a small polaron hopping model. [ABSTRACT FROM AUTHOR]

The proton-conducting properties of lanthanum tungstates (LWOs) with high La/W ratios were investigated using electrochemical measurements and quantum chemical calculations. Single phases of LWOs with high La/W ratios (6.3≤La/W≤6.7) were synthesized by high-temperature sintering at around 1700 °C. The electrical conductivity of LWO increased with increasing La/W ratio in the single-phase region. The LWO synthesized at the optimum sintering temperature and time, and with the optimum La/W ratio gave the maximum conductivity, i.e., 2.7×10 −3 S cm −1 with La/W=6.7 at 500 °C. Density functional theory calculations, using the nudged elastic band method, were performed to investigate the proton diffusion barrier. The results suggest that the proton diffusion paths around La sites have the lowest proton diffusion barrier. These findings improve our understanding of LWO synthesis and the proton-conducting mechanism and provide a strategy for improving proton conduction in LWOs. [ABSTRACT FROM AUTHOR]

In this study, we introduced tungstate into solid oxide fuel cells (SOFCs) for the first time by using a La/Pr-doped CeO 2 (LCP)/K 2 WO 4 composite as the electrolyte, which exhibited remarkably enhanced grain boundary conduction compared to that of single-phase LCP. The composition dependence of the electrical conductivity was investigated. As a result, the composite with 10 wt% K 2 WO 4 was proven to be the optimum ratio, revealing a significantly higher ionic conductivity than LCP, along with a negligible electronic conductivity. The fuel cell using the LCP/K 2 WO 4 electrolyte displayed an encouraging performance of 500 mW cm − 2 at 550 °C. These findings indicate that the LCP/K 2 WO 4 composite is a promising electrolyte for low-temperature SOFCs. [ABSTRACT FROM AUTHOR]