TiO3 Composites Research Articles

Investigation on coupling between ferro-orderings and energy harvesting properties of nickel ferrite and strontium modified barium titanate composites

Environment-friendly, low power-consuming magnetoelectric composites possess the interesting coupling between various ferro-order parameters and find applications in magnetic sensors, waveguides, transducers, spintronics, four-state memory devices, etc. The particulate composites (x)NiFe2O4–(1 − x)Ba0.9Sr0.1TiO3 were prepared using the hybrid sol-gel method using the conventional ceramic double-sintering method. The ferromagnetic nickel ferrite crystallized into a cubic crystal structure whose x-ray diffraction (XRD) peaks could be indexed to Fd3¯m space group. The ferroelectric strontium-substituted barium titanate crystallized to a tetragonal crystal structure with P4mm space group. Presence of both crystal symmetries and elemental compositions as per the proposed stoichimetry were observed from experimental results (XRD and electron microscopy techniques). Koop's phenomenological theory could be employed to explain the impedance spectra in the range of 1 kHz to 1 MHz. The effect of Maxwell–Wagner polarization and space charge polarization on the dielectric properties of composites have been observed. The Arrott plot technique successfully explains the suitability of composites for high-energy storage applications. The coupling between both ferro-orderings has been revealed from the magneto-dielectric curves and its dependency on the microstructure has been observed. The magnetocapacitance increased with the increase in NiFe2O4 composition in the (x)NiFe2O4–(1 − x)Ba0.9Sr0.1TiO3 composite. The 30% NiFe2O4 in (x)NiFe2O4–(1 − x)Ba0.9Sr0.1TiO3 composite exhibited overall better energy harvesting (η = 62.9%) and magnetodielectric properties (MC = 1.4%, MI = 20% at 1 kHz).

Mn-Doped NaNbO3/Na0.5Bi0.5TiO3 Lead-Free Ferroelectric Ceramics with Enhanced Energy Storage Performance

NaNbO3-based ferroelectric composites are regarded as a highly promising typical energy storage material. In this work, 0.02xMnO2−(1−x)NaNbO3−xBi0.5Na0.5TiO3 composites were prepared by the solid-state sintering method and their microstructure, energy storage performance, and temperature stability were analyzed. As observed by the SEM images, the addition of Bi0.5Na0.5TiO3 to NaNbO3 in appropriate amounts can effectively suppress grain growth, which is beneficial for improving the breakdown field strength. When x = 0.3, an optimal value of 210 kV/cm is achieved. Meanwhile, as 2θ = 33.2°, the most intense XRD peak can be observed, indicating excellent solid solubility between the phase components. Consequently, 0.006MnO2–0.7NaNbO3–0.3Bi0.5Na0.5TiO3 composites demonstrated an impressive discharging storage density of 2.464 J/cm3 and a considerable energy storage efficiency of 85.8%. In addition, within the temperature range of 30–80 °C, the fluctuation in energy storage density remains below 10%. All the above performances indicate that this type of material exhibits excellent practicality in the field of pulse power supply.

Thermoelectric enhancement in perovskite type textured Me0.85TiO3 ceramics by synergistic high-entropy and microstructure manipulations

Enhancing the figure-of-merit (ZT) for thermoelectric ceramics essentially needs strategies that aim to concurrently optimize electron and phonon transport properties to decouple their coupling relationship. This work developed 〈001〉 -textured Me0.85TiO3(Me = La, Sr, Ba, Ca) ceramics (LSBC-T) with a texture fraction of 92 % fabricated by a tape casting process combined with template grain-growth method, in which 10 wt% (001) oriented plate-like SrTiO3 serves as template seed and A-site deficient high-entropy (La0.25Sr0.25Ba0.25Ca0.25)0.85TiO3 composite was used as matrix material. A peak ZT of 0.27 was attained at 1073 K in the sample parallel to the tape casting direction which was twice the ZT = 0.13 of the non-textured sample. Quantitative analysis of atomic displacement disorder of A-site elements would provide an atomistic-scale understanding of grain orientation evolution with high texture degree and the low thermal conductivity of 1.79 W/(m‧K) at 1073 K. The complex multi-scale defects consist of cation and oxygen vacancies, edge dislocations, parallel grain boundaries, phase interfaces, nanoscale metal/inorganic coexisting clusters, and metal Bi sandwich layer, which act as additional phonon scattering centers while affecting carrier transport, covering all frequency phonons (100 GHz-15 THz). In addition, multi-scale parallel interfaces, including atomic-scale crystal (00l) plane of SrTiO3 seed, nano-scale “core-shell” interface parallel to the (00l) plane, metal Bi particle forming a sandwich layer in SrTiO3 seed, and “brick-wall” textured grain boundaries, make the electrical and thermal conductivity exhibiting obvious anisotropy in this LSBC-T high-entropy textured ceramics. By utilizing texture engineering in high-entropy systems, this work provides a theoretical foundation and technical support for the advancement of microstructure manipulations to reduce the inherent lattice thermal conductivity, achieve electrical and thermal conductivity anisotropy to decouple the electron–phonon coupling relationship, and thereby enhance thermoelectric properties.

Quenching induced modified nanoarchitectonics in the dielectric and energy storage behavior of poly (vinylidene fluoride)/Ba0.7Sr0.3TiO3 composites thick films

Quenching induced modified nanoarchitectonics in the dielectric and energy storage behavior of poly (vinylidene fluoride)/Ba0.7Sr0.3TiO3 composites thick films

Structural and electrical characterization of Gd and Li modified Bismuth Sodium Strontium Titanate

Structural and electric characteristics of Gd, Li and Sr modified Bismuth Sodium Titanate i.e. (Bi0.5Na0.5)0.6(Gd0.5Li0.5)0.2Sr0.2TiO3 (BNGLST) composition is demonstrated. BNGLST was synthesized by the solid-state mixed oxide method using the stoichiometrically weighed constituent oxides and carbonates. The homogenously wet mixed powder was calcined at 1000 °C for 12h and compressed pellets were sintered at 1250 °C for 2h. X-ray diffraction was carried out to confirm the phase formation. Crystallographic information was extracted from the Rietveld refinement of the XRD data. Dielectric measurement was carried out from room temperature to 300 °C at 1 kHz − 1 MHz frequencies. The a.c. conductivity associated with oxygen ion conduction is discussed in detail as a function of temperature and frequency.

Electrical properties and electromagnetic radiation characteristics of cement/Ba0.06Bi0.47Na0.47TiO3 composites

Electrical properties and electromagnetic radiation characteristics of cement/Ba0.06Bi0.47Na0.47TiO3 composites

Resonant Magnetoelectric Coupling of Fe-Si-B/Pb(Zr,Ti)O3 Laminated Composites with Surface Crystalline Layers.

The resonant magnetoelectric (ME) effect of Fe78Si9B13/Pb(Zr,Ti)O3 (FeSiB/PZT) composites with a surface-modified Fe78Si9B13 amorphous alloy has been studied. The surface-modified FeSiB can improve the ME coefficient at the resonant frequency by optimizing the magnetomechancial power conversion efficiency. The maximum ME coefficient of the surface-modified ribbons combined with soft PZT (PZT5) is two-thirds larger than that of the composites with fully amorphous ribbons. Meanwhile, the maximum value of the ME coefficient with surface-modified FeSiB ribbons and hard PZT (PZT8) is one-third higher compared with the fully amorphous composites. In addition, experimental results of magnetomechanical coupling properties of FeSiB/PZT composites with or without piezoelectric layers indicate that the power efficiency of the composites first decreases and then increases with the increase in the number of FeSiB layers. When the surface crystalline FeSiB ribbons are combined with a commercially available hard piezoelectric ceramic plate, the maximum magnetoelectric coupling coefficient of the ME composite reaches 5522 V/(Oe*cm), of which the electromechanical resonant frequency is 23.89 kHz.

Effect of k-ion-rich substitution on structural, thermally assisted relaxation processes in Na0.5Bi0.5TiO3 relaxor ferroelectric

Utilizing a complex impedance technique, we employed a probing approach to investigate the dielectric relaxation and electrical transport characteristics in lead-free Na0.5-xKxBi0.5TiO3 compositions (where x = 0.30, 0.35, 0.40, and 0.45). X-ray diffraction and Raman analysis confirmed the tetragonal phase of all compositions. This study affirms the presence of mostly bulk resistive (grain) contributions in the materials. The most notable grain resistance (Rg) was found at approximately 0.8 M ohm-m for the composition with x = 0.45 at a temperature of 500 °C. The increase in Rg strongly supports the role of K+1 as a suppressor of grain growth, leading to an increased presence of grain boundaries with an enhancement in intrinsic breakdown strength. This study validated the occurrence of non-Debye-type dielectric relaxation across all examined compounds with Negative Temperature Coefficient of Resistance (NTCR) type behavior. The pivotal role of oxygen vacancies in the conduction mechanism was affirmed through Arrhenius's theory. Particularly, the most elevated Ea values, 1.37 eV, and 1.48 eV, were observed in the case of x = 0.45 (NKBT-45). The similarity between activation energies derived from conduction and relaxation processes supports that the responsible charge carriers governing electrical transport remain consistent. Moreover, evidence of Polar Nanoregions (PNRs) formation is indicated by the separation observed between normalized Z″(f) and M″(f) peaks in NKBT-45. This observation suggests a transition from long-range conduction to localized dipolar relaxation.

Structural and Dielectric Investigation of Lithium and Strontium Modified Bismuth Sodium Titanate Composite

Crystal structure and Dielectric properties investigation of lead-free Bi0.35Na0.25Li0.1Sr0.3TiO3 (BNLST) composite is reported. The required solid solution was synthesized using oxides and carbonates via the solid-state reaction method. The stoichiometrically weighed and mixed powder was calcined at 800 °C for 12 h, and the pellets were sintered at 1250 °C for 2 h. XRD measurements confirm the formation of single-phase rhombohedral perovskite structure and the crystal structure was refined using the X’Pert High-score plus software. The full-width half maxima of the XRD peak was used to compute the average crystallite size employing the Debye-Scherrer, Williamson-Hall, and Halder-Wagner techniques. The BNLST's dielectric measurements were performed as a function of temperature at five distinct frequencies in the range of 100 Hz–1 MHz. The phase transition temperatures are shifted toward room temperature with the doping of Li and Sr. The diffuseness parameters of the phase transition, the a.c. electrical conductivity and the activation energy are estimated for the BNLST composite.

Degradability of methylene orange synthetic dyes of multiferroic NiFe2O4–Ba0.8Sr0.2TiO3 composites

Five samples of xNiFe2O4/(1 − x)Ba0.8Sr0.2TiO3 (where x = 0, 0.1, 0.2, 0.3, and 0.4) multiferroic nanocomposites have been successfully fabricated using ball milling combined with heat treatment in a short time. X-ray diffraction patterns indicated the coexistence of two phases, namely, NiFe2O4 (NFO) and Ba0.8Sr0.2TiO3 (BSTO). The average grain size obtained is about 50–100 nm, and NFO and BSTO phases are evenly distributed in the samples. With an increase in the content of NFO, the values characterizing the ferroelectric and ferromagnetic properties improve significantly. Furthermore, the bandgap energy (Eg) value was also strongly reduced. The results on the degradability of methylene orange show that the apparent first-order rate of composites containing NFO with x = 0.4 was found to be k = 0.0228 min−1, which is significantly higher than that of pure BSTO (k = 0.0166 min−1), suggesting that NFO/BSTO multiferroic nanocomposites could be considered as candidate photocatalysts for the degradation of pollutants.

Modified poly(phenylene oxide)/(CaSr)TiO3 composites with ultrahigh permittivity and low loss for microwave substrates

Polymer/ceramic composites used as microwave dielectric combine the excellent dielectric properties of ceramic with the toughness of polymer. The properties of composites are not only determined by the properties of components but also influenced by the polymer-ceramic interface. In this work, we conducted experiments and simulations on the dielectric properties and thermal conductivity of modified poly(phenylene oxide)/(CaSr)TiO3 (mPPO/CST) composites. A comparison of composites filled with different sizes (2.5, 11, and 20 µm) of CST fillers demonstrates that smaller particle (more filler-matrix interface) is beneficial to mechanical properties but detrimental to dielectric properties and heat transfer. The finite element simulation results are in good agreement with the experimental values, which is of significance for guiding future experiments. The composite filled with 80 wt. % CST20 has a high relative density of 97%, an ultrahigh εr of ∼20, and a low tan δ of 0.0019 at 10 GHz. Meanwhile, the mPPO/CST composites are eco-friendly and suitable for mass production and are promising candidates for automotive and aerospace applications.

Magnetoelectric response in laminated BaFe12O19/Pb(Zr,Ti)O3 composites

The magnetoelectric (ME) response of laminated composites consisting of BaFe12O19 and Pb(Zr,Ti)O3 ceramics is systematically investigated. A butterfly-shaped curve of a magnetoelectric coefficient emerges in both three-layer and multilayer composites. We show that the appearance of a 7 ppm residual strain in the BaFe12O19 layer after magnetization is the main reason for this special curve. We also observe the self-biasing effect of the composites and a maximum ME response from 0.6 to 5 mV/(Oe cm) in laminated composites with magnetic and ferroelectric layers of different thicknesses that can be measured at a zero-bias magnetic field. The repeatable and stable maximum and minimum values of the magnetoelectric coefficient can be obtained under periodically applied biasing magnetic fields, which is important for a practical device application. An electric-field control of ferromagnetism, evidenced by a 17%–19% enhancement in the magnetization of the BaFe12O19 layer after Pb(Zr,Ti)O3 is polarized, is observed in the composites, implying potential applications in memory devices for the composites. Our work indicates that both magnetic field-controlled polarization and electric-field-controlled magnetization exist in BaFe12O19/Pb(Zr,Ti)O3 laminated composites.

Studies on structural, dielectrics and magnetics properties of two stage sintered (1-x) Mg0.3Zn0.7Fe2O3–xBa0.7Sr0.3TiO3 composite

The (1-x)Mg0.7Zn0.3Fe2O4 – (x)Ba0.7Sr0.3TiO3 composites with x = 0.40, 0.50 and 0.60 were prepared by solid state reaction under two step sintering. Two step sintering conditions were determined by the first step (T1) at 1350 °C for holding time of 60 min and cooled down to the second sintering temperature (T2) with different temperatures between 900 and 1100 °C for holding time of 5 h. The sample with high percentage of shrinkage and dense ceramic was obtained from 0.4Mg0.7Zn0.3Fe2O4-0.6Ba0.7Sr0.3TiO3 with sintering of T2 at 1100 °C. XRD pattern showed combination of ferrite phase (Mg0.7Zn0.3Fe2O4) and ferroelectric phase (Ba0.7Sr0.3TiO3) and secondary phase of ZnO. Rietveld analysis confirmed main phases of Mg0.7Zn0.3Fe2O4 and Ba0.7Sr0.3TiO3, including MgFe2O4 and ZnO as secondary phase. It was found that the unit cell volume of Ba0.7Sr0.3TiO3 was smaller than Mg0.7Zn0.3Fe2O4 unit cell volume. Therefore, the short distance between ions of Ba0.7Sr0.3TiO3 phase produced the dense composites with increasing ferroelectric phase contents. The average grain size of ceramic was in the range of 0.74–1.07 µm with grain square shape in Mg0.7Zn0.3Fe2O4 phase and the average grain size of 0.59–0.70 µm with round oval shape in Ba0.7Sr0.3TiO3 phase. The dielectric constant was between 0.8 × 103 and 5.4 × 103 in the temperature range of 275 °C − 360 °C. The highest dielectric constant was obtained from 0.6Mg0.7Zn0.3Fe2O4 −0.4Ba0.7Sr0.3TiO3 with T1 at 1350 °C with holding time for 60 min and T2 at 900 °C with holding time for 5 h. The hysteresis measurement was carried out to determine saturation magnetization, remanent magnetization and coercivity of the composites. The results revealed that higher concentration of ferrite led to optimal magnetic properties.

Magnetically Tuned Impedance and Capacitance for FeGa/PZT Bilayer Composite under Bending and Longitudinal Vibration Modes

A magnetically tunable magnetoelectric transducer consisting of rectangular Fe82Ga18(FeGa)/Pb(Zr,Ti)O3(PZT) composites is developed, and their magnetoimpedance and magnetocapacitance effects are investigated under bending and longitudinal modes. Specifically, the composites' impedance and capacitance are found to vary with dc magnetic field Hdc, which results from the varied effective dielectric permittivity of the FeGa/PZT composite with Hdc due to the delta E effect, magnetostrictive effect of FeGa and mechanism responsible for ME coupling between the FeGa and PZT layers. Furthermore, the FeGa/PZT bilayered composite exhibits both bending and longitudinal vibration modes due to the asymmetrical stress distributions. The maximum ΔZ/Z of the FeGa/PZT composite is about 215% at the antiresonance frequency fa = 28.78 kHz of the bending-mode, which is 2.53 times as high as that at the antiresonance frequency fa = 107.9 kHz of the longitudinal mode, while the maximum ΔC/C of the FeGa/PZT composite is about 406% at the resonance frequency fr = 28.5 kHz of the bending mode, which is 3.5 times as high as that at the antiresonance frequency fa = 106.6 kHz of the longitudinal mode. This study plays a guiding role for the design and corresponding application of magnetic sensors, magnetic-field-tuned electronic devices and multiple frequency ultrasonic transducers.

Preparation and catalytic properties of ZnO/ Na0.5Bi0.5TiO3 composites

ZnO/Na0.5Bi0.5TiO3 composites were prepared by chemical hydrothermal deposition and hydrothermal method and the effects of ZnO adding on the properties of Na0.5Bi0.5TiO3 were investigated. The results show that the ZnO/Na0.5Bi0.5TiO3 composite with 5% ZnO content has the best photocatalytic performance and good cycling stability. Under simulated sunlight irradiation, the degradation rate for MB (10 mg/L) by ZnO/Na0.5Bi0.5TiO3 composites reached 100% within 20 minutes, and the reaction rate constant was 0.07427min−1, which were 27.51 and 6.00 times higher than those of Na0.5Bi0.5TiO3 (NBT, 0.0027 min−1) and ZnO (0.01237min−1), respectively. The incorporation of ZnO on the Na0.5Bi0.5TiO3 can form Z-scheme heterostructure ZnO/Na0.5Bi0.5TiO3 and increase the specific surface area, inhibiting the recombination of electron and hole and improving separation and transfer carriers efficiency. ZnO/Na0.5Bi0.5TiO3 composites have potential applications in high-efficiency and high-activity photocatalysts to degrade organic pollutants.

Effect of Crystal Structure and Phase on the Dielectric, Ferroelectric, and Piezoelectric Properties of Ca2+- and Zr4+-Substituted Barium Titanate

Barium titanate (BaTiO3) and its associate ternary metal oxide systems constitute versatile materials with immense potential for various technological applications in electronics and optoelectronics. Herein, we report on the synthesis and property optimization of lead-free ceramic samples, namely BaTiO3 (BT), BaZr0.2Ti0.8O3 (BZT), Ba0.7Ca0.3TiO3 (BCT), and BaZr0.2Ti0.8O3–0.5 Ba0.7Ca0.3TiO3 (BZT–BCT) composites. All of these materials were synthesized by the standard solid-state chemical reaction method, where tuning the composition and the crystal structure yields materials suitable for multifaceted applications related to capacitors, memory storage, and high-energy switching and transducers. Structural studies carried out using X-ray diffraction and Raman spectroscopy confirm the tetragonal phase for BT, BZT, and BZT–BCT samples, whereas BCT is a biphasic crystal system, which contains a small amount of the CaTiO3 phase. Scanning electron microscopy characterization of the surface morphology indicates the granular-dense microstructures of all of the samples. Energy dispersive spectroscopy confirms the high degree of purity and chemical homogeneity of the synthesized samples in addition to a well-maintained composition. Density measurements using Archimedes principles show that all of the samples have densities above 4.96 g/cm3. All of these materials exhibit typical polarization–electric field (P–E) hysteresis and field-induced strain butterfly (S–E) loops, which confirm their ferroelectric and piezoelectric nature. The frequency response of the dielectric constant shows a maximum dielectric constant of 2441 for pure BT and it decreases for higher frequencies, above 0.1 MHz. The dielectric properties of BT imply significant prospects for its future capacitor applications. Ferroelectric measurements, which are established by measuring the P–E hysteresis loop at 300 K, show that the BCT samples exhibit a 0.50 squareness ratio. The detailed analyses indicate that BCT is a candidate material for permanent memory storage device (FeRAM) applications, whereas BZT is good for switching applications. Furthermore, a moderately higher remnant polarization (Pr = 10.81 μC/cm2) is obtained for BT and a lower coercive field (Ec = 0.78 kV/cm) is obtained for the BZT sample. Also, piezoelectric coefficient and strain measurements show that BT has a piezoelectric coefficient of 183 ± 1 pC/N and a converse piezoelectric coefficient of 365.7 ± 2 pm/V, which are the highest values. The Q-factor for the BZT–BCT composite was observed to be 4.16 × 10–4 (cm2/μC)2, which is maximum, implying that BZT–BCT is suitable for energy conversion transducer applications. In this work, we comprehensively elucidate and discuss the properties and potential applications of BT and its associated ternary metal oxide systems.

Sintering Temperature Driven Structural, Dielectric, Ferroelectric, and Piezoelectric Properties of 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 Lead-Free Composites

Lead-free 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 composites have been synthesized via sol-gel chemical route. We have systematically investigated the influence of sintering temperature on the structural and electrical properties of the BZT-BCT composites. The 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 composites were prepared by combining Ba(Zr0.2Ti0.8)O3 (BZT) and (Ba0.7Ca0.3)TiO3 (BCT) powders and sintered at different temperatures 900-14000C. The electrical properties of BZT-BCT composites improve with increasing sintering temperature. The composites sintered at 1300 and 14000C exhibit enhanced ferroelectric properties with spontaneous polarization Ps ~ 11.2 μC/cm2 and 8.66 μC/cm2 respectively. The dielectric and piezoelectric properties of BZT-BCT composites also improve with increasing sintering temperature. The dielectric constant value εʹ ~ 2938, tan δ ~ 0.016 and piezoelectric co-efficient d33 ~ 278 pC/N were measured for BZT-BCT composite sintered at 14000C while observing a considerably high transition temperature of Tc ~ 1200C. The observed results are discussed in terms of structural and microstructural analysis as a function of sintering temperature.

Effective dielectric properties of Cement/Ba0.06(Na0.5Bi0.5)0.94TiO3 composites: A comparative approach

Lead-free ceramic powder of a morphotropic phase boundary composition Ba0.06(Na0.5Bi0.5)0.94TiO3 (BNBT) was prepared from a solid-state synthesis route. The cement-ceramic (1−ϕ)cement/ϕBNBT; 0 ≤ ϕ 1.0 composites were fabricated. The filler concentration-dependent values of the bulk density and real part of complex permittivity showed an increasing trend of variation while the apparent porosity and imaginary part of complex permittivity followed a decreasing trend. In order to test the acceptability of dielectric mixture equations of the inclusion material in the mixture, five such equations have been chosen. The Bruggeman, and Rother-Lichtenecker equations showed their coherence with minimal deviation from the experimental results of the real part of complex permittivity for the entire measurement range of volume fractions. Also, a first-order exponential growth/decay type of mathematical model was suggested which could fit the experimental data excellently well (r2 > 0.97).

Study of piezo-sensing characteristics of 0–3 cement/Ba0.06Na0.47Bi0.47TiO3 composite using drop weight impact method

In this work the voltage response and the generated electrical energy of cement/Ba0.06Na0.47Bi0.47TiO3 (60:40 wt%) (Cement/BNBT) composite under impact loading (drop-weight impact method) are presented. The MPB composition of Ba0.06Na0.47Bi0.47TiO3 (BNBT) ceramic powder has been prepared by a solid-state synthesis process at 1140 °C/4h in the air atmosphere. The formations of BNBT and Cement/BNBT composite were ascertained from the X-ray diffraction study. Also, the surface morphology of Cement/BNBT(40%) composite was examined from a scanning electron microscope. The output voltages and the generated electrical energy of Cement/BNBT(40%) were increased with the increase in the applied mechanical energy. The mechanical impact sensing characteristics of Cement/BNBT(40%) from the drop weight impact method by making use of IC-555 timer in astable mode connection has also been undertaken. The output pulse width and dielectric constant were found to increase with the increasing applied mechanical energy. Hence, the present piezo-composite system could be utilized as a sensing material for structural health monitoring applications in different civil infrastructures.

Electrical Properties of Novel La0. 2Sr0.7-xCaxTi0.95Fe0.05O3-δ Based Fuel Electrode for Solid Oxide Cell

As the fuel electrode is a central component of solid oxide fuel cell (SOFCs), evaluation of novel fuel electrode materials for SOFCs has become a favorite research subject. Perovskite structure offers an excellent framework for altering the chemical and physical properties of a material due to its ability to accommodate many different cations. In the present research novel La0.2Sr0.7-xCaxTi0.3Fe0.7O3-δ (LSCFT) fuel electrode compositions have been synthesized by glycine-nitrate reaction for high-temperature solid oxide fuel cell application. For analysis of the influence of Sr/Ca ratio on the electrical conductivities of different compositions of LSCFT, the DC four-probe conductivity measurement method has been performed. Conductivities have been measured at three different atmospheres: synthetic air; 97% H2 + 3% H2O and in 1%H2 + 3% H2O + 96% Ar. The crystal structure and microstructure have been studied using X-ray diffraction and SEM, respectively to confirm the purity of phase and percentage of porosity.In previous studies by Irvine et al. [1] has been demonstrated the effect of calcium doping on A-site deficient lanthanum strontium titanate, which displayed enhancement of its electrical conductivity and maximum conductivity was observed for La0.20Sr0.25Ca0.45TiO3 (LSCT) composition. Moreover, the same composition was tested and it confirmed as an active fuel electrode in fuel cell conditions, where good performance was achieved [2].Keywords: Fuel electrode, Electrical conductivity, Layered Perovskite, MIEC material, high temperature SOFC.[1] Aljaberi AD, Irvine JTS. Ca-substituted, A-site deficient perovskite La0.2Sr0.7TiO3 as a potential anode material for SOFCs. J Mater Chem A 1 (2013) 5868-74.[2] Verbraeken MC, Iwanschitz B, Mai A, Irvine JTS. Evaluation of Ca doped La0.2Sr0.7TiO3 as an alternative material for use in SOFC anodes. J Electrochem Soc 159 (2012) F757-62.