Chemical State, Site, Solid Solubility, and Magnetism of Fe in the Ferropericlase (Mg1–x Fe x )O Produced by Ball Milling of MgO and Fe

Ferropericlase (Mg_1–x Fe _x )O solid solution was prepared by ball milling of the mixture of MgO with a rock-salt structure and metal Fe powders in atmosphere and at room temperature. Differing from (Mg_1–x Fe _x )O prepared at high temperature by using MgO and FeO as starting materials, the solution of Fe in MgO is not continuous but limited in the ball milling process, and the solubility limit is less than 30 at. pct. About 92 pct of the Fe ions occupy the site of tetrahedral oxygen coordination in trivalent Fe (Fe³⁺) with high spin, whereas about 8 pct of the Fe ions occupy the site of octahedral oxygen coordination in bivalent Fe (Fe²⁺) with high spin. The Fe³⁺ and Fe²⁺ ions do not show a ferromagnetic but show a paramagnetic state. The as-milled (Mg_1–x Fe _x )O is metastable and decomposes to ferropericlase (Mg_1–y Fe _y )O (where y < x) and MgFe₂O₄ with spinel structure as annealed above 773 K (500  °C), and the content of Fe in the (Mg_1–y Fe _y )O increases with increasing annealing temperature. A bulk (Mg_1–x Fe _x )O was fabricated by annealing the as-milled (Mg_1–x Fe _x )O powders at 973 K (700  °C). It shows n-type conductivity, which is attributed to an electronic small polaron with an activation energy of 0.135 eV.     

Wastewater treatment using Fe-doped perovskite manganites by photocatalytic degradation of methyl orange,crystal violet and indigo carmine dyes in tungsten bulb/sunlight

We documented(ⅰ) the decolorization of wastewater in visible light,which contains methyl orange,crystal violet and indigo carmine dyes,using La_0.7Sr_0.3Mn_1-xFe_xO₃(x=0.0,0.05,0.1 and 0.5) manganites and(ⅱ) efficient separation of photocatalysts from water using magnetic field.These ceramic photocatalysts were sintered at 1050℃ for 12 h.Ceramics were characterized by X-ray diffraction(XRD),soft X-ray absorption spectroscopy(SXAS),Fourier transf...     

Effect of doped strontium on catalytic properties of La1‒xSrxMnO3 for rhodamine B degradation

A series of La_1‒xSr_xMnO₃ samples were prepared by sol–gel method and used to degrade rhodamine B (RhB) in water. All samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N₂ adsorption–desorption, temperature-programmed reduction of H₂ (H₂-TPR) and temperature-programmed desorption of O₂ (O₂-TPD). The results show that the degradation of RhB is highly dependent on the initial pH value of solution. Sr doping enhances the degradation ability of LaMnO₃ for RhB in the time range of 0–40 min under a strong acidic environment, but all samples exhibit similar degradation rate from 40 to 60 min. In La_0.7Sr_0.3MnO₃–RhB reaction system, there are two different degradation pathways, including N-de-ethylation, chromophore cleavage, ring-opening and mineralization. La_1‒xSr_xMnO₃ (x ≤ 0.3) has the perovskite structure of La–Mn oxides, while La_0.6Sr_0.4MnO₃ exhibits a Sr_0.4MnLa_0.6O_2.98 perovskite phase. Sr doping leads to distortion of rhombohedral crystal structure and increases the relative content of Mn⁴⁺. The perovskite structure is stable in strong acidic environment during RhB degradation, but the relative content of Mn⁴⁺ and Mn³⁺ on the material surface changes. Sr doped LaMnO₃ achieves specific surface area of 58.8 m²/g and total pore volume of 0.152 cm³/g. Furthermore, Sr²⁺ doping improves redox properties of La–Mn oxides, and the presence of defects makes oxygen diffusion easier compared with the undoped samples.     

Mechanical properties,thermophysical properties and electronic structure of Yb3+ or Ce4+-doped La2Zr2O7-based TBCs

First-principles calculations based on density functional theory were performed to investigate the cohesive energies, elastic modulus, Debye temperatures, thermal conductivities and density of states of La_2−xYb_xZr₂O₇, La₂Zr_2−xCe_xO₇ and La_2−xYb_xZr_2−xCe_xO₇ (x = 0.00, 0.25, 0.50, 0.75, 1.00) ceramics. The results show that doping Yb³⁺ or Ce⁴⁺ into La₂Zr₂O₇ reduces its elastic modulus, thermal conductivity and Debye temperature. Compared with La_2−xYb_xZr₂O₇ (x ≠ 0.00), La₂Zr_2−xCe_xO₇ compounds have better ductility and lower Debye temperature. The Debye temperature values of La₂Zr_2−xCe_xO₇ (x ≠ 0.00) compounds are in the range of 485.0–511.5 K. Among all components, the fluorite-type La_2−xYb_xZr_2−xCe_xO₇ (x = 0.75, 1.00) compounds exhibit better mechanical and thermophysical properties, and their thermal conductivity values are only 1.213–1.246 W/(m∙K) (1073 K), which are 14.5%–16.7% lower than that of the pure La₂Zr₂O₇. Thus, our findings open an entirely new avenue for TBCs.     

Study on electrical conductivity of FexO–CaO–SiO2–Al2O3 slags

The composition dependences of electrical conductivity of Fe_xO–CaO–SiO₂–Al₂O₃ slags at different oxygen potentials and temperatures have been studied experimentally in the present work. From the experimental results, the total electrical conductivity and electronic conductivity for all the slags monotonously decrease as increasing CO/CO₂ ratio from about 0 to 1. With the increase of Fe_xO content, the total electrical conductivity and electronic conductivity increase at a fixed CO/CO₂ ratio. It is also found that the ionic conductivity of all the studied slags increases as increasing the CO/CO₂ ratio, which is resulted from the increase of Fe²⁺ ion concentration. In addition, the temperature dependences of ionic, electronic and total conductivity for different compositions obey the Arrhenius law. The electronic transference number exhibits a strong relationship with oxygen potential, but is independent of temperature.     

Variation of optimum yttrium doping concentrations of perovskite type proton conductors BaZrl_xYxO3-~ （0~~~_0.3） with temperature

A solid state reaction method was used to prepare the perovskite-structured compounds BaZrl-xYxO3-a （x=0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3）. The X-ray diffraction （XRD） pattern indicated that the target perovsldte phases were obtained. With increasing Y con- centration the unit cell parameters of BaZrl-xYxO3-a samples were expanded, and Y doping became more difficult. However, high synthesis temperature is helpful to promote Y doping. The SEM results showed that the samples exhibited poor sinterability with in- creasing Y-doping content. Thermal gravimetric （TG） curves analysis showed the more mass decreasing of BaZrl-xYxO3-a （0≤x≤0.3） samples at high temperature with more Y doping and more proton introducing. The electrochemical impedance spectra （EIS） of specimens showed that conductivities of BaZrl_xYxO3（0≤x≤0.3） increased with increasing temperature from 300 to 900 ℃ in wet air. At 900 ℃, the conductivity of BaZrl-xYxO3-a （0≤x≤0.3） first increased with increasing doped amount of Y, and reached the high- est value of 1.07x 104 S/cm when x was 0.2, then decreased gradually with further increasing Y content. At 600 ℃, BaZr0.75Y0.2503-a displayed the highest conductivity, while the conductivity of BaZro.rYo.303-a was the highest at 300 ℃. The results indicated that there should be an optimum Y doping concentration yielding the highest conductivity at a constant temperature, and the optimum Y doping concentration should increase in the humidity atmosphere as the temperature decreases. So increasing the Y-doping concen- tration is helpful to improve the conductivities of BaZrl-xYxO3-a materials at low temperature.     

Photoluminescent properties of tunable green-emitting oxynitride （Baa-xSrx）Si6012N2 ：Eu2＋ phosphor and its application in white LEDs

Green emitting Eu2＋-doped （Ba3_xSrx）Si6012N2 solid solutions were synthesized through solid state reaction at 1350 ℃ for 10 h under a N2/H2 atmosphere. The XRD patterns revealed that the solid solution series of （Ba3 x-ySrx）Si6Ol2N2：yEu2＋ with x value ranging from 0-0.6 were established. An efficient and intense tunable green light was observed by varying the cation Sr/Ba ratio. The emission spectra exhibited an entire shift towards long wavelength with increasing ofx value, which was caused by large crystal field splitting and Stokes shift. The x value dependence of emission intensity was discovered and explained by the enhanced probability of electron from excited 4f state to 5d ground state via nonradioactive transition. Highly thermal stability and feasible color coordinates were verified. White LEDs with excellent photochromic properties were fabricated by packing GaN based blue chips and （Ba Sr）3Si6012N2：Eu2＋ phosphors. All results indicated that the （Ba3_xSrx）SirO12N2：Eu2＋ phosphors were confirmed to be a promising candidate for pc-white LEDs in solid state lighting.     

Preparation and characterization of Ce_(0.8)La_(0.2–x)Y_xO_(1.9) as electrolyte for solid oxide fuel cells

In this study, ultrafine Ce0.8La0.2–x Y x O1.9（for x=0, 0.05, 0.10, 0.15, 0.20） powders were successfully prepared by the sol-gel method.The samples were characterized by fourier transform infrared（FTIR）, thermogravimetric and differential scanning calorimetry（TG-DSC）, X-ray diffraction（XRD）, scanning electron microscopy（SEM）, AC impedance and thermal expansion measurements.Experimental results indicated that highly phase-pure cubic fluorite electrolyte Ce0.8La0.2–x Y x O1.9 powders were obtained after calcining at 600 °C.The as-synthesized powders exhibited high sintering activity, the Ce0.8La0.2–x Y x O1.9 series electrolytes which have higher relative densities over 96% could be obtained after sintered at 1400 °C for 4 h.Ce0.8La0.15Y0.05O1.9 electrolyte sintered at 1400 °C for 4 h exhibited higher oxide ionic conductivity（σ800 oC=0.057 S/cm）, lower electrical activation energy（E a=0.87 e V） and moderate thermal expansion coefficient（TEC=15.5×10-6 K-1, temperature range 25–800 °C）.     

Effect of rare earth and transition metal La-Mn substitution on electrical properties of co-precipitated M-type Ba-ferrites nanoparticles

In the current research work Ba_(1-x)La)xMn)yFe_(12-y)O_(19) hexa-ferrite nanoparticles of different compositions were synthesized using chemical co-precipitation technique. The structural properties were explored using X-ray diffractions(XRD), scanning electron microscopy(SEM) and Fourier transmission infrared spectroscopy(FTIR). XRD indexed pattern confirms the formation of M-type hexagonal phase. The crystallite size of synthesized samples ranges from 13 to 34 ± 2 nm. FTIR peaks observe also confirmed the presence of metaloxygen bond of the desired product. The position of peak at 467 cm~(-1) corresponds to A_2 u vibration for octahedral Fe(4+)-O and peak position E1 u corresponds to vibration of Fe(3+)O4 octahedral bonds. The band v_1 in range(677-559 cm~(-1)) and v_2 in frequency range(356-419 cm~(-1)) are associated to A and B sites.Dielectric properties of all compositions were measured with frequency. The dielectric constant, loss and tangent loss decrease from 26 to 9, 25 to 2 and 0.94 to 0.14, respectively with frequency. DC electrical resistivity is increased with dopant concentration increasing from 2.15 × 10~4 to 1.92 ×10~5 Ω·cm.     

Structural and electrical properties of La2-xSrxMo2O9-δ

Sr-doped La2Mo2O9 were prepared by solid state reaction and characterized by XRD,impedance spectroscopy and HebbWagner polarization method.XRD patterns of the samples indicated that the solubility limit of Sr2+ in La2-xSrxMo2O9-δ was in the range of 7 mol.% to 7.5 mol.%,i.e.,the maximum stoichiometric coefficient x in La2-xSrxMo2O9-δ was larger than 0.14 and less than 0.15.The cubic lattice parameter of La2-xSrxMo2O9-δ(0相似文献   

Synthesis and characterization of tungsten and barium co-doped La_2Mo_2O_9 by sol-gel process for solid oxide fuel cells

Herein, we demonstrate the synthesis of W and Ba co-doped La_2Mo_2O_9(LBMWO) nanocrystalline powder by a sol-gel process. In all the compositions have general formulae La_(1.9)Ba_(0.1)Mo_(2-x)W_xO_(8.95)(x = 0-0.40). The crystal structure, microstructure and conductivity of LBMWO were characterized by X-ray diffraction, scanning electron microscopy and electrical impedance spectroscopy. In addition, the thermal and decomposition properties of the LBMWO gel were analyzed by differential scanning calorimetry-thermogravimetric. The results reveal that all LBMWO powders calcined at 700 ℃ have a cubic structure;the average crystallite size is about 48 nm. The unit cell parameter of LBMWO powders increases with increase in W content. The as-synthesized nanocrystalline LBMWO samples exhibit excellent sinterability and a relatively lower sintering temperature of 900 ℃. A high relative density of -96% is achieved after sintering at 900 ℃ which is in good agreeme nt with the re sults of the SEM. Moreover, W and Ba codoping suppresses the phase transition and effectively stabilizes the β-phase at low temperature. At the same time,La_(1.9)Ba_(0.1)Mo_(1.85)W_(0.15)O_(8.95) exhibits high ionic conductivity, 3.07 x 10~(-2) S/cm at 800 ℃. It is therefore concluded that co-doping can improve the properties of La_2MO_2O_9 electrolytes.     

Influence of partial substitution of cerium for lanthanum on magnetocaloric properties of La_(1–x)Ce_xFe_(11.44)Si_(1.56) and their hydrides

The structure and magnetocaloric properties of La1–xCexFe11.44Si1.56 and their hydrides La1–xCexFe11.44Si1.56Hy（x=0, 0.1, 0.2, 0.3, 0.4） were investigated.The samples crystallized mainly in the cubic Na Zn13-type structure with a small amount of α-Fe phase as impurity.The lattice constants and Curie temperature presented the same change tendency with increasing of Ce content.For the hydrides, the influence of Ce content on lattice constants was weakened and the values of H concentration y were approximate to be 1.56.The La1–xCexFe11.44Si1.56 compounds exhibited large values of isothermal entropy change –ΔSm around the Curie temperature TC under a low magnetic field change of 1.5 T.The value of –ΔSm increased and then decreased with increasing Ce content, reached the maximum, 26.07 J/kg·K for x=0.3.TC increased up to the vicinity of room temperature by hydrogen absorption for the Ce substituted compounds, but TC only slightly decreased with increasing Ce content.The first-order metamagnetic transition was still kept in the hydrides and the maximum values of –ΔSm were lower than those of the La1–xCexFe11.44Si1.56 compounds, but still remained large values, about 10.5 J/kg K under a magnetic field change of 1.5 T.The values of –ΔSm were nearly independent of the Ce content and did not increase with increasing x for the hydrides.The La1–xCexFe11.44Si1.56Hy（x=0–0.4） hydrides exhibited large magnetic entropy changes, small hysteresis loss and effective refrigerant capacity covered the room temperature range from 305 to 317 K.These hydrides are very useful for the magnetic refrigeration applications near room temperature under low magnetic field change.     

Synthesis and luminescence properties of a novel phosphor Ca2–x/2Si1–xPxO4:Eu2+for near UV-excited white-light-emitting diodes

A novel green-emitting phosphor,Eu2+-doped Ca2-x/2 Si1-x Px O4(0.25≤x≤0.30),was prepared through a conventional solidstate reaction.X-ray diffraction(XRD),photoluminescence(PL) and decay studies were employed to characterize the sample,which was assigned to P63mc space group in the hexagonal system.The effect of P-doping on the α-Ca2 SiO4 was studied and P2 O5 broken down by the raw material of(NH4)2 HPO4 played an important role in stabilizing α-Ca2 SiO4 which can only be stable at high temperature.The XRD patterns of the Ca2-x/2 Si1-x Px O4 host were found pure and optimized when the mole fraction of P2 O5 was 14.5%.The diffuse reflectance spectra of the Ca1.855 Si0.71 P0.29 O4 and Ca1.845 Si0.71 P0.29 O4 :0.01Eu2+covered the spectral region of 230-400 nm,implying that the phosphor was suitable for UV or near-UV LED excitation.The phosphor could be effectively excited in the near UV region with the maximum at 372 nm.The emission spectrum of the Ca1.845 Si0.71 P0.29 O4 :0.01Eu2+phosphor showed an asymmetrical single intensive band centered at 513 nm,which corresponded to the 4f65d1→4f7transition of Eu2+.Eu2+ions might occupy two types of Ca2+sites in the Ca1.855 Si0.71 P0.29 O4 lattice and form two corresponding emission centers,which led to the asymmetrical emission of Eu2+in Ca1.855 Si0.71 P0.29 O4.The effects of Eu2+-doped concentration in Ca1.855-x Si0.71 P0.29 O4 :xEu2+on the PL were also discussed,the optimum doping concentration of Eu2+was 1 mol.% and the critical distance of the energy transfer was also calculated by the concentration-quenching method.The non-radiative energy transfer between Eu2+seemed to be caused by the multipole-multipole interaction.The fluorescence lifetime of Eu2+was found to be 0.55711 μs.The results suggested that these phosphors might be promising candidates used for near UV light excited white LEDs.     

Experimental Liquidus Studies of the Pb-Fe-Si-O System in Equilibrium with Metallic Pb

Phase equilibria of the Pb-Fe-Si-O system have been investigated at 943 K to 1773 K (670 °C to 1500 °C) for oxide liquid in equilibrium with liquid Pb metal and solid oxide phases: (a) quartz, tridymite, or cristobalite; (b) (fayalite + tridymite) or (fayalite + spinel); (c) spinel (Fe₃O₄); (d) complex lead-iron silicates (melanotekite PbO·FeO_1.5·SiO₂, barysilite 8PbO·FeO·6SiO₂, 5PbO·FeO_1.5·SiO₂, and 6PbO·FeO_1.5·SiO₂); (e) lead silicates (Pb₂SiO₄, Pb₁₁Si₃O₁₇); (f) lead ferrites (magnetoplumbite Pb_1+x Fe_12?x O_19?x solid solution range); and (g) lead oxide (PbO, massicot). High-temperature equilibration on primary phase or iridium substrates, followed by quenching and direct measurement of Pb, Fe, and Si concentrations in the phases with the electron probe X-ray microanalysis, has been used to accurately characterize the system in equilibrium with Pb metal. All results are projected onto the PbO-“FeO”-SiO₂ plane for presentation purposes. The present study is the first systematic characterization of liquidus over a wide range of compositions in this system in equilibrium with metallic Pb.     

Er and Gd Co-Doped Ceria-Based Electrolyte Materials for IT-SOFCs Prepared by the Cellulose-Templating Method

Ce_0.9?x Gd_0.1Er _x O_1.9?x/2 (0 ≤ x ≤ 0.1) (EGDC) powders were successfully synthesized with a fast and facile cellulose-templating method for the first time and characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The samples were calcined at a relatively low calcination temperature of 773 K (500 °C). The sintering behavior of the calcined EGDC powders was also investigated at 1673 K (1400 °C) for 6 hours. Calcined Ce_0.9?x Gd_0.1Er _x O_1.9?x/2 (0 ≤ x ≤ 0.1) powders and sintered Ce_0.9?x Gd_0.1Er _x O_1.9?x/2 (0 ≤ x ≤ 0.1) pellets crystallized in the cubic fluorite structure. It was found that the relative densities of the sintered EGDC pellets were over 95 pct for all the Er contents studied. Moreover, the effect of Er content on the ionic conductivity of the gadolinium-doped ceria (GDC, Ce_0.9Gd_0.1O_1.90) was investigated. The highest ionic conductivity value was found to be 3.57 × 10^?2 S cm^?1 at 1073 K (800 °C) for the sintered Ce_0.82Gd_0.1Er_0.08O_1.91 at 1673 K (1400 °C) for 6 hours.     

Er3+-substituted W-type barium ferrite: preparation and electromagnetic properties

Er3+-substituted W-type barium ferrites Ba1-xErx(Zn0.3Co0.7)2Fe16O27(x=0.00,0.05,0.10,0.15,0.20)were synthesized by polymer adsorbent combustion method.Samples were characterized by X-ray diffraction analysis(XRD),X-ray fluorescence(XRF),scanning electron microscopy(SEM)and network analyzer to investigate the relationships among Er3+concentration,crystal structure,surface mcrphology and electromagnetic properties.All the XRD patterns showed pure phase of W-type barium ferrite when x≤0.15,while the impurity phase of ErFeO3 appeared when x=0.20.The pure W-type barium ferrite showed a hexagonal flake shape.In addition,the microwave electromagnetic properties of samples were analyzed in the frequency range of 2-18 GHz.It was indicated that the electromagnetic properties were significantly improved when Er3+doping content was 0.10.The reasons were also discussed using electromagnetic theory.The optimized ferrite exhibited excellent microwave absoption performance.The maximum of reflection loss(RL)reached about-27.4 dB and RL was below-10dB at the frequency range from 8.4 GHz to 18 GHz,when the thickness was 2.6 mm.     

Effect of dysprosium substitution on magnetic and structural properties of NiFe_2O_4 nanoparticles

This work investigated the effect of dysprosium(Dy)ions on the structural,microstructural and magnetic properties of nickel nanospinelferrite,NiFe_2 O_4.The nanoparticles(NPs)of NiDy_xFe_(2-x)O_4(0.0≤x≤0.1)were prepared via the hydrothermal method.The formation of cubic phase of Ni nanoferrite was confirmed through X-ray diffraction,field emission scanning and transmission electron microscopy.Moreover,the magnetic properties of NiDy_xFe_(2-x)P_4(0.01≤x≤0.10)NPs were discussed.The magnetization versus field,M(H)curves exhibit super paramagnetic nature at room temperature and ferrimagnetic nature at low temperature(10 K).A noticeable improvement in the different deduced magnetic parameters is obtained especially for the NiDy_(0.07)Fe_(1.93)O_4(x = 0.07)product.The obtained result is mostly derived from the substitution of Fe~(3+)ions of smaller ionic radii with Dy~(3+)ions of larger ionic radii that will strengthen the super exchange interactions among nanoparticles.The calculated squareness ratios are found to be much less than 0.5,due to the effect of spin disorder in the surface regions of NiDy_xFe_(2-x)O_4(0.01≤x≤0.10)NPs.The Dy~(3+) ions substitution increases the magnetic hardness(higher values of remanence M_r,coercivity H_c,and magnetic moment n_B)of nickel nanoferrite samples.     

Chemical interaction of Ce-Fe mixed oxides for methane selective oxidation

Chemical interaction of Ce-Fe mixed oxides was investigated in methane selective oxidation via methane temperature programmed reduction and methane isothermal reaction tests over Ce-Fe oxygen carriers. In methane temperature programmed reduction test, Ce-Fe oxide behaved complete oxidation at the lower temperature and selective oxidation at higher temperatures. Ce-Fe mixed oxides with the Fe content in the range of 0.1–0.5 was able to produce syngas with high selectivity in high-temperature range(800–900 °C), and a higher Fe amount over 0.5 seemed to depress the CO formation. In isothermal reaction, complete oxidation occurred at beginning following with selective oxidation later. Ce1–xFexO2–δ oxygen carriers(x≤0.5) were proved to be suitable for the selective oxidation of methane. Ce-Fe mixed oxides had the well-pleasing reducibility with high oxygen releasing rate and CO selectivity due to the interaction between Ce and Fe species. Strong chemical interaction of Ce-Fe mixed oxides originated from both Fe*activated CeO2 and Ce3+ activated iron oxides(FeOm), and those chemical interaction greatly enhanced the oxygen mobility and selectivity.     

Preparation and performance of Pr-doped Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ) cathode for IT-SOFCs

(Ba0.5Sr0.5)1-xPrxCo0.8Fe0.2O3-δ(BSPCFx;x=0.00-0.30) oxides were synthesized by a sol-gel thermolysis process using combination of PVA and urea,and were also investigated as cathode material for intermediate temperature solid oxide fuel cells(IT-SOFCs).X-ray diffraction(XRD) results showed that all the samples formed a single phase cubic pervoskite-type structure after being calcined at 950 oC for 5 h and the lattice constant decreased with the Pr content increasing.The electrical conductivity of Ba0.5Sr0.5Co0.8Fe0.2O3-δ(BSCF) was greatly enhanced by Pr-doping.The thermal expansion coefficient(TEC) of BSPCFx was increased with the content of Pr increasing,and all the thermal expansion curves had an inflection at about 250-400 oC due to the thermal-induced lattice oxygen loss and the reaction of Co and Fe ion.Ac impedance analysis indicated that BSPCFx possessed better electrochemical performance.The polarization resistance of the sample with x=0.2 was only ～0.948 Ω cm2 at 500 oC,significantly lower than that of BSCF(～2.488 Ω cm2).