Terms Of Phase Structure Research Articles

Development of high-performance perovskite La(Mg2/3Nb1/3)O3 electrolyte with hybrid protonic/oxide ion conduction for low-temperature solid oxide fuel cells

Perovskite structures material such as the doped barium cerate-zirconates possessing high concentration and mobility of proton defects have drawn substantial attention. However, the low thermodynamic stability of alkaline earth cations hinders it further application in solid oxide fuel cells (SOFCs). From this point of view, lanthanum-based perovskites without alkaline earth metals can be considered as suitable electrolyte material for SOFC. In this study, a new perovskite material La(Mg2/3Nb1/3)O3 (LMN) is introduced as a high performing electrolyte with considerable proton conduction conductivity of 0.0023S cm−1 at 550 °C for low temperature solid oxide fuel cells (LT-SOFCs). LMN electrolyte is characterized in terms of phase structure, morphological feature and surface properties. It is found that LMN sample is stable under fuel cell condition and deliver promising performance with a maximum output power density of 742 mW cm−2 at 550 °C. Moreover, concentration cells experiment confirmed that the LMN possessed hybrid proton/oxide conduction and was dominated by proton conduction surface properties. Our work thus vouch that LMN can be an efficient alternative electrolyte for low temperature fuel cell applications.

Micro/Nanostructured Bioactive Titanium Implant Surface with Sol-Gel Silicate Glass Nanoparticles.

To develop a surface coating of sol-gel 70S30C bioactive glass (BAG) nanoparticles on titanium disks and dental implants and characterize the BAG coating from the standpoint of average surface roughness, adhesion strength, and coating stability upon implant insertion under clinical settings. BAG was prepared using a modified sol-gel technique, then milled into nanoparticles. The resultant powder was characterized in terms of phase structure, composition, and particle size. Titanium disks and dental implants were coated with BAG nanoparticles via electrophoretic deposition. Surface characterization of coated implants was conducted. Uncoated and BAGcoated implants were examined for average surface roughness using a confocal laser scanning microscope. Pull-off tests were conducted to measure the adhesion strength of the BAG coating to the underlying disks. To measure the amount of coating loss and evaluate the effect of insertion on coating thickness, coated implants were inserted under clinical settings into artificial and natural bones. BAG nanoparticles had an amorphous structure with particle sizes < 20 nm in diameter. Electrophoresis resulted in a continuous coating that covered the whole implant surface. Microscopic analysis confirmed the porous nanostructure of the BAG coating, which formed a homogenous surface with microcracks. The BAG coating had a uniform thickness of 35.38 ± 4.67 μm. The average surface roughness was significantly lower for BAG-coated implants, with less surface irregularities (3.34 ± 0.45 μm for uncoated implants, 1.45 ± 0.23 μm for BAG-coated implants). An adhesion strength of 18.51 ± 3.37 MPa was recorded for the BAG coating. After insertion into artificial bone, 66.23 ± 10.23% of the coating weight remained on the implant surface. A reduction in the thickness of the BAG coating only occurred in sites of high friction with bone after implant insertion into bovine bone. Coating titanium implants with 70S30C BAG nanoparticles is attainable through electrophoretic deposition and results in a homogenous coating layer with a moderately rough surface, considerable adhesion strength, and high coating stability during implant insertion. Int J Oral Maxillofac Implants 2023;38:591-606. doi: 10.11607/jomi.10272.

Role of crystallized solid solution on the ductile/brittle behavior and tribological performance of Cr-V-C nanocomposite films

Cr-V-C nanocomposite films are experimentally and computationally studied in terms ofphase structure, hardness, and ductile/brittle behavior. Alloying Cr-C composite with V significantly promotes the film crystallization directly by encouraging face-centered-cubic (fcc) (Cr, V)C solid solution to form. The hardness and ductile/brittle behavior of Cr-V-C nanocomposite films are determined by the elastic property of crystalline (Cr, V)C compounds and the interfacial slip between the V-doped nanocrystalline and amorphous matrix. The addition of V atoms can effectively block the growth of columnar grains. The column-free V-rich nanocomposite films with dense structure and high hardness significantly resist destructive wear both in air and seawater conditions, exhibiting a minimal wear rate of about 8.0 × 10−7 mm3 /(Nm).

Enhancing ORR Catalytic Activity and Electrochemical Investigation of La1−2xBaxBixFeO3 Cathode for Low-Temperature Solid Oxide Fuel Cell

Perovskite cathodes have emerged as a promising alternative to traditional cathode materials in low-temperature solid oxide fuel cells (LT-SOFCs) due to their exceptional catalytic properties and high oxygen reduction reaction (ORR) activity. Their fast catalytic activity and chemical stability have drawn significant attention to lowering the operating temperature of SOFCs. In this study, Ba2+ and Bi3+ are doped into LaFeO3. The aim is to investigate the catalytic activity and electrochemical performance of LT-SOFCs. The presented cathode material is characterized in terms of phase structure, surface morphology, and interface studies before being applied as a cathode in SOFCs to measure electrochemical performance. The XPS study revealed that La1−2xBaxBixFeO3 (x = 0.1) exhibits enriched surface oxygen vacancies compared to La1−2xBaxBixFeO3 (x = 0.2). La1−2xBaxBixFeO3 with (x = 0.1 and 0.2) delivers a peak power density of 665 and 545 mW cm−2 at 550 °C, respectively. Moreover, impedance spectra confirmed that La1−2xBaxBixFeO3 with x = 0.1 exhibits lower electrode polarization resistance (0.33 Ω cm2) compared to La1−2xBaxBixFeO3 with x = 0.2 (0.57 Ω cm2) at 550 °C. Our findings thus confirm that LBBF cathode-based SOFCs can be considered a potential cathode to operate fuel cells at low temperatures, and it will open up another horizon in the subject of research.

Tribology comparison of laser-cladded CrMnFeCoNi coatings reinforced by three types of ceramic (TiC/NbC/B4C)

In this study, three composite coatings were prepared by laser cladding, selecting the ceramic particles (B4C, TiC, or NbC), together with the powders of high-entropy alloy (HEA), i.e. CrMnFeCoNi. The results demonstrate that the composite coatings reinforced by varied carbides exhibited special microstructures, which lead to the features of micro-cutting wear, three-body wear, and fatigue wear, respectively. Therefore, the differences between the three composite coatings were compared, and evaluated in terms of phase structure, microstructure, chemical composition, nanoindentation, and phase interface correlation. Ultimately, the wear resistance mechanisms of selected ceramic particles reinforced HEA coatings were explained, and their applicability was estimated.

Micro/nanostructured bioactive titanium implant surface with sol-gel silicate glass nanoparticles

Andrew M. Shenoda, BDS/Maged A. Gadallah, MSc/Rahaf M. Darwish, MSc/Mona S. Saad, PhD/Mona K. Marei, PhD: Purpose: To develop a surface coating of sol-gel 70S30C bioactive glass (BAG) nanoparticles on titanium disks and dental implants and to characterize the results in terms of average surface roughness, adhesion strength, and coating stability upon implant insertion under clinical settings. Materials and Methods: BAG was prepared with the modified sol-gel technique, then milled into nanoparticles. The resultant powder was characterized in terms of phase structure, composition, and particle size. Titanium disks and dental implants were coated with BAG nanoparticles by electrophoretic deposition. Surface characterization of coated implants was conducted. Uncoated vs BAG-coated implants were examined for average surface roughness by a confocal laser scanning microscope. The pull-off test was conducted to measure the adhesion strength of BAG coating to the underlying disks. Coated implants were inserted under clinical settings into artificial and natural bone to measure the amount of coating loss and to evaluate the effect of insertion on coating thickness. Results: BAG nanoparticles had an amorphous structure, with a particle size of < 20 nm in diameter. Electrophoresis resulted in a continuous coating covering the whole implant surface. Microscopic analysis confirmed the porous nanostructure of BAG coating, which formed a homogenous surface with microcracks. BAG coating had a uniform thickness of 35.38 ± 4.67 μm. Average surface roughness was significantly lower for BAG-coated implants, with a reduction of surface irregularities (3.34 ± 0.45 μm for uncoated implants, 1.45 ± 0.23 μm for BAG-coated implants). Adhesion strength of 18.51 ± 3.37 MPa was recorded for BAG coating, and 66.23% ± 10.23% of the coating weight was found to remain on the implant surface after insertion into artificial bone. A reduction in BAG coating thickness occurred only in sites of high friction with bone after implant insertion into bovine bone. Conclusion: Coating titanium implants with 70S30C BAG nanoparticles is attainable through electrophoretic deposition and results in a homogenous coating layer with a moderately rough surface, considerable adhesion strength, and high coating stability observed during implant insertion.

A novel water quench approach for enhancing the surface characteristics of electroless nickel phosphorous deposit

Usually, heat-treated electroless NiP deposits (NiP) were cooled using air quenching (AQ) process for enhancing its surface properties. As of now, no research work reported the surface characteristics of heat-treated NiP followed by water quenching (WQ) process. Hence, a novel attempt has been made to report the preliminary investigation on the properties of WQ-NiP. The deposits were heat treated (400°C, 500°C, 600°C and 700°C) at the rate of 0.5°C/s followed by air and water cooling. Comparative investigations have been made between the as-plated, AQ-NiP, WQ-NiP in terms of phase structure, crystallite size, residual stress, rockwell hardness, microstructure, and work of adhesion. Additionaly, the failure mechanisms of various heat-treated NiP during indentation were investigated and reported in this article. There is a restriction observed in the growth of crystallite for WQ-NiP as compared to the as-plated and AQ-NiP. The solubility of the intermediate phases has induced compressive residual stress for both AQ-NiP and WQ-NiP at 600°C and 700°C. Nickel oxide precipitate was observed in the microstructure of AQ-NiP and WQ-NiP heat treated at 700°C. The work of adhesion is considerably increased for WQ-NiP as compared to AQ-NiP. Maximum hardness of about 53.7 HRC was obtained for WQ-NiP treated at 400°C.

Construction and Mechanism Analysis of a Self-Assembled Conductive Network in DGEBA/PEI/HRGO Nanocomposites by Controlling Filler Selective Localization.

Herein, a feasible and effective approach is developed to build an electrically conductive and double percolation network-like structure via the incorporation of highly reduced graphene oxide (HRGO) into a polymer blend of diglycidyl ether of bisphenol A/polyetherimide (DGEBA/PEI). With the assistance of the curing reaction-induced phase separation (CRIPS) technique, an interconnected network of HRGO is formed in the phase-separated structure of the DGEBA/PEI polymer blend due to selective localization behavior. In this study, HRGO was prepared from a unique chemical reduction technique. The DGEBA/PEI/HRGO nanocomposite was analyzed in terms of phase structure by content of PEI and low weight fractions of HRGO (0.5 wt.%). The HRGO delivered a high electrical conductivity in DGEBA/PEI polyblends, wherein the value increased from 5.03 × 10−16 S/m to 5.88 S/m at a low content of HRGO (0.5 wt.%). Furthermore, the HRGO accelerated the curing reaction process of CRIPS due to its amino group. Finally, dynamic mechanical analyses (DMA) were performed to understand the CRIPS phenomenon and selective localization of HRGO reinforcement. The storage modulus increased monotonically from 1536 MPa to 1660 MPa for the 25 phr (parts per hundred in the DGEBA) PEI polyblend and reached 1915 MPa with 0.5 wt.% HRGO reinforcement. These simultaneous improvements in electrical conductivity and dynamic mechanical properties clearly demonstrate the potential of this conductive polyblend for various engineering applications.

Origin of high piezoelectricity in low-temperature sintering PZT-based relaxor ferroelectric ceramics

Multilayer piezoelectric devices need to co-sinter the piezoelectric ceramic layers and the Ag-rich Ag–Pd internal electrode layers at a low temperature (less than the Ag melting point of 961.78 °C), and need to use Sn–Zn-based lead-free solder to weld the components at 260 °C. This requires low-temperature sintering of high-performance piezoelectric ceramics with a Curie temperature (Tc) higher than 260 °C. Thereby low-temperature (940 °C) sintering 0.09 Pb(Ni1/3Nb2/3)O3‒ 0.03 Pb(Mg1/2W1/2)O3‒0.88 Pb(Zr0.5Ti0.5)O3 ceramics are prepared via the solid-state reaction method. Samples added with different Ta2O5 contents are fabricated and compared in terms of phase structure, microstructure, piezo-/ferro-electric properties, and dielectric relaxation. High piezoelectric properties (d33 = 640 pC/N, d33∗ = 676 p.m./V, Tc = 303 °C) are achieved in the 0.70 wt% Ta2O5 added ceramic with a minimum activation energy of domain wall movement (Ea) of 0.025 eV. Rietveld refinement and Raman spectroscopy show that all the ceramics exhibit rhombohedral-tetragonal (R-T) coexistence and the distortion degree of crystal structures increases with the increase of Ta2O5 content. Our results show that the larger the content of the tetragonal phase (CTP), the lower the Ea, the smaller the domain, and the higher the piezoelectric response. Low Ea favors orientation and extension of polar regions and facilitates the formation of the nanometer-size domain structure (polar nanoregions) which is observed by using piezoresponse force microscopy, thus resulting in high piezoelectric properties. This mechanism associated with the CTP, the Ea and the domain structure reveals the origin of the high piezoelectricity in the low-temperature sintering PZT-based relaxor ferroelectric ceramics.

Shape manipulation of porous CeO2 nanofibers: facile fabrication, growth mechanism and catalytic elimination of soot particulates

In this work, shape manipulation in porous CeO2 nanofibers was successfully achieved by a simple electrospinning technology with high quality and high reproducibility. By simply tuning the electric field strength during electrospinning, the diameter of as-spun nanofibers composed of Ce(acac)3 and polyvinylpyrrolidone can be precisely controlled. As a result, the morphology of nanofibers can change from columnar to celery-like and belt-like structure. The formation mechanism of this intriguing diameter-dependent morphology can be assigned to the gradient evaporation of solvent across the nanofiber. After calcination at 500 °C, porous CeO2 nanofibers were obtained, showing unusually observed celery-like or belt-like morphologies. These intriguing CeO2 nanofibers exhibited good thermal stability in terms of phase structures and morphologies up to 700 °C. The fibrous CeO2 mats were active toward soot combustion with decreased activation energy, compared with commercial samples. Among three kinds of shapes, the fibrous CeO2 mats made of columnar-like nanofibers were endowed with the lowest activation energy of 120.1 kJ/mol, due to the most effective contact between soot and CeO2 surface, regardless a loose contact mode.

Structural and Mechanical Characteristics of Cu50Zr43Al₇ Bulk Metallic Glass Fabricated by Selective Laser Melting.

In this work, the structural and mechanical characteristics of Cu50Zr43Al7 bulk metallic glass (BMG) fabricated by selective laser melting (SLM) are studied and the impacts from the SLM process are clarified. Cu50Zr43Al7 alloy specimens were manufactured by the SLM method from corresponding gas-atomized amorphous powders. The as-built specimens were examined in terms of phase structure, morphologies, thermal properties and mechanical behavior. The x-ray diffraction and differential scanning calorimetry results showed that structural relaxation and partial crystallization co-exist in the as-fabricated Cu50Zr43Al7 glassy samples. The nano- and micro- hardness and the elastic modulus of the SLM-fabricated Cu50Zr43Al7 BMG were higher than CuZrAl ternary BMGs with similar compositions prepared by conventional mold casting, which can be attributed to the structural relaxation in the former sample. However, the macro compressive strength of the SLM-fabricated Cu50Zr43Al7 BMG was only 1044 MPa mainly due to its porosity. This work suggests that the SLM process induced changes in structural and mechanical properties are significant and cannot be neglected in the fabrication of BMGs.

Mechanical properties of 1 mol% CeO2‐10 mol% Sc2O3 co‐doped and stabilized ZrO2 synthesized through hydro/solve‐thermal method

AbstractUltra‐fine 1 mol% CeO2‐10 mol% Sc2O3 co‐doped and stabilized ZrO2 (1Ce10ScSZ) powders with average grain size less than 10 nm in diameter were prepared by hydro/solve‐thermal method using either deionized water, ethanol, or methanol as solvent. As‐synthesized powders were characterized in terms of phase structure, particle morphology, and chemical composition by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), high‐resolution transmission electron microscopy (HRTEM), and inductively coupled plasma‐optical emission spectroscopy (ICP‐OES), respectively. Sintering studying was conducted on pellets of 15 mm in diameter and 3 mm in thickness under uniaxial compaction using 25 MPa at either 600, 800, 1000, 1100, 1200, 1400, or 1500°C for 1 hour. Phase transitions and grain morphologies of those sintered samples were characterized by XRD and field emission scanning electron microscopy (FESEM). Mechanical properties were characterized on dense pellets sintered at 1500°C by nanoindentation. Experimental results showed that ethanol was more effective to synthesize agglomerate‐free 1Ce10ScSZ powders as compared with deionized water and methanol. Choice of solvent affected the environment of hydro/solve‐thermal solution, which led to variation of chemical compositions of powders and porosities of sintered pellets, and therefore, influenced their mechanical performance. Our study showed that solvent was important to make dense, thin, and mechanically robust 1Ce10ScSZ electrolyte for potential applications in electrochemical devices. Absolute values of hardness (H) and Young's modulus (E) measured from our samples are much higher and more consistence than those results obtained from commercial vendors reported in literatures.

Hydrogen generation from hydrolysis of NaBH4 based on high stable NiB/NiFe2O4 catalyst

Recently environment-friendly hydrogen generation for NaBH4 hydrolysis using improved method has attracted much attention. Here a novel catalyst NiB/NiFe2O4 was developed through an impregnation-chemical reduction method, which was utilized in hydrogen production from NaBH4 hydrolysis. In this study, NiFe2O4 ferrite supports were prepared via a combined EDTA-citric acid complexing method. NiFe2O4 ferrites were characterized in terms of phase structure and surface morphologies using X-ray diffractometer as well as scanning electron microscopes. It can be found that the particle size of NiFe2O4 calcined at 873 K is about 30–40 nm which exhibits an optimized spherical morphologies. The factors such as active metal loading amount, reaction temperature and recycling number on NiB/NiFe2O4 catalyst were investigated in detail. A hydrogen generation rate as high as 299.88 ml min−1 g−1 for NiB/NiFe2O4 catalyst can be achieved using 5wt.% NaBH4 solution at 298 K which is much higher than pure NiB. Moreover, an improved recycling stability can be obtained for supported NiB/NiFe2O4 catalyst. The 83.3% of initial catalytic activity can be retained for NiB/NiFe2O4 catalyst after the fifth run. The experimental results show that the usage of NiFe2O4 support can enhance the catalytic activity and recycling stability of NiB active metals.

Enhanced surface properties of plain carbon steel using plasma nitriding with austenitic steel cathodic cage

Non-alloyed steels are very popular in a wide range of applications due to their low cost, but unfortunately, they are not favorable to surface enhancement by nitriding process because of high brittleness. This problem can be overcome by introducing special alloying elements (such as chromium) on the surface by pre-treatment or admixing of alloys in the bulk, but it is not very cost effective. In this study, plain carbon steel specimens are processed by the cathodic cage plasma nitriding (CCPN) technique using an austenitic stainless steel cathodic cage (CC) having variable diameters (13–21cm). It is observed that the nitriding process significantly improves the hardness without any pre-treatment or admixing of alloys, which is very useful for industrial applications due to reduced cost and processing time. Also, the corrosion and wear rates are significantly reduced. The results are understood in terms of phase structure, crystalline size and strain using XRD analysis, reactive species emission from the plasma using optical emission spectroscopy and SRIM simulation.

One‐Step Surfactant‐Free Hydrothermal Synthesis of Platelike Sodium Niobate Template Powders

A one‐step surfactant‐free hydrothermal route is developed to prepare platelike NaNbO3 template powders. At optimal KOH concentration, pure platelike NaNbO3 with rhombohedral structure (width and thickness of 20 and 2 μm, respectively) is obtained at 200°C for 16 h. After calcination at 600°C for 4 h, the structure of the hydrothermally synthesized NaNbO3 changes from rhombohedral to orthorhombic, whereas the initial platelike morphology is maintained. Such characteristics in terms of phase structure, elemental composition, and morphology render our hydrothermally synthesized NaNbO3 suitable for textured ceramic fabrications.

Application of symmetric solid oxide fuel cell in fuel containing sulfur: I. Effect of electrodes

Symmetric solid oxide fuel cells (SFCs) with double perovskite materials serving as symmetric electrodes are applied for the first time in fuel containing sulfur, aiming to explore solution to sulfur poison. Temperature-programmed techniques, including H2-TPR, O2-TPD, were used to evaluate catalytic activities of electrodes in different atmosphere, while stabilities of electrode materials in sulfur containing fuel gas were characterized in terms of phase structures, conductivity, and microstructures by SEM, four-probe method and XRD as a function of temperature and operating time. It is evidenced that Sr2CoMoO6 (denoted as SCMO) possesses better hydrogen reducibility, oxygen desorption and stability in sulfur containing fuel gas. In configuration of Sr2XMoO6 (X = Co, Ni)|Ce0.85Sm0.15O2−δ (SDC)|Sr2XMoO6, the maximum power density Pmax reaches 95 mW cm−2 for SCMO and 68 mW cm−2 for SNMO with H2-0.1% H2S at 750 °C. Lower polarization resistance of SCMO (about 2.7 Ω cm2 at 750 °C) is achieved. It is interestingly noted that SFC performance composed of ex-situ regenerated symmetric electrodes SCMO falls only by 21%, as compared to that of fresh electrodes. The combinations of thermal analysis (TG-DTA) and surface analysis (XPS) convince that an ex-situ regeneration of symmetric electrode can be realized.

Suppression effect of decarburization by dry-ice blasting on plasma-sprayed steel coatings: Structure, wear performance and magnetic properties

Steel coatings prepared by atmospheric thermal spraying with dry-ice blasting were studied in terms of phase structure, magnetic and wear behaviors. It was found that dry-ice blasting could suppress the volatilization of carbon during spraying process due to the exclusion effect of carbon dioxide gas sublimated from dry-ice pellets on the oxygen. Moreover, the fractographic observation of the deposited coatings proved the removal effect of dry-ice blasting on the splashing particulates which were distributed with poor bonding strength between the splat layers. In addition, it has been found that the magnetic properties are sensitive to the direction in the coating, although steel coating presents a ferromagnetic character in the parallel and vertical directions. Steel coating deposited with dry-ice blasting possesses a relatively lower saturation magnetization but has a superior wear resistance because of the suppression of decarburization during the spraying process.

Enhanced Performance of Alkaline Niobate-Based Ceramics Manufactured by Two-Step Sintering

In this paper, a typical Li- and Ta/Sb- modified alkaline niobate-based ceramics are prepared by conventional sintering and two-step sintering respectively. The ceramics sintered by two-step sintering exhibit better electrical properties than the samples prepared by conventional sintering. The related mechanisms are also discussed in terms of phase-structures and microstructures. Results show that two-step sintering can restrain the volatilization of alkali elements and compositional segregation during the process of sintering dense alkaline niobate-based ceramics, and enhance the electrical properties accordingly. Therefore, two-step sintering is a promising approach to achieve high performance alkaline niobate-based ceramics.

Nanostructure of a Glass-Like Carbon Characterized by X-Ray Diffraction and Electron Energy Loss Spectroscopy

In our present study, phenolic resins heated at different temperatures from 600 oC to 3000 oC were analysised in terms of phase structure and chemical structure using X-ray diffraction and high resolution transmission electron microscopy equipped with an electron energy loss spectrometer (EELS). It is shown that materials appear to be amorphous with many micro-pores surrounded by crystalline graphite layers; the formation of the pore is due to the gas evolution reaction. Using the intensities of peaks in EELS CK-ionization edge which arise from transition of an atomic 1s electron to the π* and σ* antibonding band-like states, the percentage of sp2-bonded carbon have been analyzed and the results reveal notable differences with heat treatment temperature.

Preparation and evaluation of new composites as anodes for intermediate-temperature solid oxide fuel cells

Composites, which consist of Sr-doped LaCrO 3, CeO 2, and NiO, were prepared according to a general formula (La 0.7Sr 0.3) 1−xCe xCr 1−xNi xO 3−δ (x = 0–0.6) and were assessed as anodes for intermediate-temperature solid oxide fuel cells (ITSOFCs) in terms of phase structure, electrical conductivity, thermal expansion coefficient, and fuel cell performance. Results showed, for x > 0.2, CeO 2 and NiO precipitated after being calcined at 800–1450 °C and dispersed on a doped LaCrO 3 support. At 800 °C, the electrical conductivities of the composites (for x = 0.2, 0.4 and 0.6) in a humidified 3% H 2O hydrogen atmosphere were 0.72, 1.22 and 4.89 Scm − 1 , respectively. The average values of the thermal expansion coefficients of the composites (in a temperature range of 30–800 °C) were 11 × 10 − 6 (x = 0.2) and 11.5 × 10 − 6 K − 1 (x = 0.6). SOFCs with different anodes were characterized by current–voltage measurements and electrochemical impedance spectroscopy. The peak power density of a single cell with different composite anodes increased with increasing x. At 800 °C, the maximum power density was 81.5 mW cm − 2 , and the area specific resistances of the single cells under open circuit condition were 3.1 (x = 0.2) and 1.6 Ω cm − 2 (x = 0.6) using humidified (3% H 2O) hydrogen as fuel and ambient air as oxidant.