BST Powders Research Articles

Y2O3-doped BST flexoelectric ceramic energy harvester

The study employed the water-based casting technique to prepare BST sheets, which were then combined with PDMS to BST composite sheets for wind energy harvesting. By adding 0.3–1.2 mol% Y2O3 as an additive, the dielectric constant and the flexoelectric coefficient of the BST sheets were significantly enhanced. The Y2O3 and BST powders were mixed to form a casting slurry with the appropriate viscosity, which was then cast into a sheet. After the sintering process, silver electrodes were coated on both surfaces of the sheet. To enhance the flexibility of the sheet, PDMS was applied to the silver-coated surfaces, creating a "sandwich structure" composite sheet. The flexoelectric properties of the composite sheets are characterized utilized the micro cantilever beam method. The energy harvesting experiments, conducted in a simulated wind tunnel environment, demonstrate that the composite sheets exhibit varying flexoelectric properties and energy conversion efficiencies, depending on their thickness. When the doping amount of Y2O3 is 0.6mol%, the composite sheets with a BST layer thickness of 200 μm exhibit the highest flexoelectric coefficient of 1.1 μC/m; the composite sheets with a BST layer thickness of 100 μm exhibit the strongest current output capability of 4.2 nA. These findings indicate that the developed composite sheets could be promising for applications in renewable energy harvesting, particularly for capturing and converting wind energy into useable electrical power.

Preparation of BST Powders and Ceramics via a Hybrid Method

Barium strontium titanate (Ba0.8Sr0.2TiO3; BST) ceramics, were prepared by the hybrid method between Solid-state reaction (SSR) and Sol-gel methods (SG) in a ratio of 1:0.1–1:0.5. The BST powder was successfully calcined at 850 °C for 2 h. This temperature is much lower than the calcination temperatures of the SSR method. The BST ceramics were sintered between 1150 and 1450 °C. All samples showed the pure perovskite structure corresponding to JCPDS no. 34-0411. The optimum sintering temperature was observed from the samples sintered at 1450 °C for 4 h, indicating a density of 5.26 g/cm3, dielectric constant of 7018, and ferroelectric properties: (P max = 13.8 μC/cm2, P r = 2.5 μC/cm2 and E c = 2.3 kV/cm at 30 kV/cm).

Synergistic Optimization of the Thermoelectric and Mechanical Properties of Large-Size Homogeneous Bi0.5Sb1.5Te3 Bulk Samples via Carrier Engineering for Efficient Energy Harvesting.

Manufacturing an economically viable, efficient commercial thermoelectric (TE) module is essential for power generation and refrigeration. However, mediocre TE properties, lack of good mechanical stability of the material, and significant difficulties involved in the manufacturing of large-scale powder as well as bulk samples hinder the potential applications of the modules. Herein, an economically feasible single-step water atomization (WA) is employed to synthesize BST powder (2 kg) by Cu doping within a short time and consolidated into large-scale bulk samples (500 g) for the first time with a diameter of 50 mm and a thickness of about 40 mm using spark plasma sintering (SPS). The incorporation of Cu into BST greatly boosts the carrier concentration, leading to a significant increase in electrical conductivity, and inhibits the bipolar thermal conductivity by 73%. Synchronously, the lattice contribution (κL) is greatly reduced by the effective scattering of phonons by comprising fine-grain boundaries and point defects. Therefore, the peak ZT is shifted to the mid-temperature range and obtained a maximum of ∼1.31 at 425 K and a ZTave of 1.24 from 300 to 500 K for the BSTCu0.05 sample, which are considerably greater than those of the bare BST sample. Moreover, the maximum compressive mechanical strength of large-size samples manufactured by the WA-SPS process is measured as 102 MPa, which is significantly higher than commercial zone melting samples. The thermoelectric module assembled with WA-SPS-synthesized BSTCu0.05 and commercial n-type BTS material manifests an outstanding cooling performance (-19.4 °C), and a maximum output power of 6.91 W is generated at ΔT ∼ 200 K. These results prove that the BSTCux samples are eminently suitable for the fabrication of industrial thermoelectric modules.

Ultrasonic-driven polycondensation nonaqueous precipitation synthesis of Ba0.7Sr0.3TiO3 ceramics

Ba0.7Sr0.3TiO3 ceramics have excellent electrical performance and wide applications in sensors, capacitors, dynamic random access memory, and so on. High-quality Ba0.7Sr0.3TiO3 powders preparation is the premise and basis for obtaining Ba0.7Sr0.3TiO3 ceramics with excellent properties. Monodispersed Ba0.7Sr0.3TiO3 powders were synthesized using a novel ultrasonic-driven polycondensation nonaqueous precipitation method with tetrabutyl titanate, anhydrous barium acetate, and anhydrous strontium acetate as precursor materials and glycol as the solvent. Ultrasonic irradiation promotes the polycondensation of raw materials; Ba–O–Ti and Sr–O–Ti bonds form in the precipitate, facilitating low-temperature synthesis of Ba0.7Sr0.3TiO3 at 550 °C. Ultrasonic irradiation also assists in the monodispersing of precipitates and BST powders and low-temperature sintering, and considerable properties of Ba0.7Sr0.3TiO3 ceramics. The Ba0.7Sr0.3TiO3 powder and ceramic particle sizes are approximately 30–50 nm and 100–150 nm, respectively. The proposed ultrasonic-driven polycondensation nonaqueous precipitation method is expected to be widely used for preparation of ceramic powders.

Flexible ball-milled Bi0.4 Sb1.6 Te3/methyl cellulose thermoelectric films fabricated by screen-printing method

Flexible Bi[Formula: see text]Sb[Formula: see text]Te3 (BST)/methyl cellulose (MC) thermoelectric composite films were prepared by a two-step process: BST powders were successfully prepared via a ball milling method, and then BST/MC composite films with different volume fractions of BST were screen printed on flexible mixed cellulose esters membrane. As the contents of BST powders increased, the electrical conductivity was significantly improved, while the Seebeck coefficient was nearly unchanged, and a room temperature power factor (PF) of 2.32 [Formula: see text]W m[Formula: see text] K[Formula: see text] was achieved when the volume fraction of BST was 80%. After the cold-pressing treatment, both the electrical conductivity and Seebeck coefficient were improved, and a highest PF of 10.07 [Formula: see text]W m[Formula: see text] K[Formula: see text] was obtained at room temperature for the film with 80 vol.% BST, which was [Formula: see text]4.3 times higher than that of the pristine sample (2.32 [Formula: see text]W m[Formula: see text] K[Formula: see text] at room temperature). The tendency of thermoelectric performance varying with BST proportion was explained by the percolation threshold theory. This work shows the great potential of screen-printing technology in flexible and wearable electronics.

Effects of in situ BiScO3 nanoparticles on the microstructure and dielectric properties of Ba0.7Sr0.3Ti0.9925Tm0.0103@BiScO3 ceramics

Ba0.7Sr0.3Ti0.9925Tm0.01O3 (BST) and core-shell structured BST@BiScO3 ceramics were prepared via a sol-precipitation and conventional sintering method. The single perovskite structure of the BST@BiScO3 ceramic powder and bulk materials were confirmed via X-ray diffraction. Additionally, transmission electron microscopy analysis revealed that the surface of the BST powder was successfully coated in situ with amorphous BiScO3 nanoparticles. Scanning electron microscopy analysis indicated that the grain sizes of the BST@x mol.% BiScO3 (x = 1, 2, 3) ceramics decreased with increasing coating amounts. For x = 4 mol.%, the grain size of the BST@BiScO3 ceramic significantly increased relative to that of BST@x mol.% BiScO3 (x = 1, 2, 3), and some smaller particles were found to have precipitated. The results revealed that the dielectric constants of the BST@BiScO3 ceramics decreased at room temperature, but remained above 10000, and that the dielectric loss was significantly reduced. In addition, the Curie peak of BST@x mol.% BiScO3 (x = 1, 2, 3, 4) broadened and shifted to a higher temperature. The Curie peak of the BST@4 mol.% BiScO3 ceramic material was nearly a flat line. In this work, dielectric materials with high dielectric constants and low dielectric losses were successfully prepared; thus, they met the requirements of miniaturization and temperature stability for dielectric ceramics.

3D printing fabrication of porous bismuth antimony telluride and study of the thermoelectric properties

This paper reports the successful preparation of porous thermoelectric samples of bismuth antimony telluride (Bi0.5Sb1.5Te3, BST) using 3D printing technology. The porous thermoelectric samples were fabricated with selective laser sintering (SLS) method using 100 mesh BST powders. Their thermoelectric performances, including electrical conductivity, Seebeck coefficient, and thermal conductivity in the temperature range of 25℃ - 250℃ were measured. The electrical conductivity was found to have a maximum value 4.03 × 104 S/m, lower than maximum value 7.36 × 104 S/m of the bulk BST. The Seebeck coefficient of the porous samples was found have a maximum value at 190.51 μV/K, slightly higher than that of the BST bulk alloy. The minimum thermal conductivity of the porous BST samples was measured to be 0.27 W/mK at 54℃, less than 18% of minimum that for the bulk BST alloy. The thermal conductivity is reduced due to boundaries and defects formed in SLS process as well as the porous structures of the samples. The figure of merit (ZT) of the porous samples was found to have a maximum value of about 1.29, higher than that of the BST bulk material.

Effect of potassium and magnesium codoping on the dielectric properties of BST powders

ABSTRACTK and Mg codoped BST powders were prepared by a sol-gel method, and the effect of doped concentration on the dielectric performances was studied. For comparison, pure, Mg doped and K doped BST powders were studied. XRD shows all powders reveal complete diffraction peaks and ABO3 cubic perovskite polycrystalline structures. Compared to the pure BST powder, Mg doped BST powder shows a little weaker crystallization, 5%∼15% K doped BST powders exhibit stronger crystallization, and the crystallization is getting stronger with increasing K doped concentrations from 2% to 15%. BST powder shows lattice parameter of 3.963 Å, Mg doping corresponds to 3.963 Å, 2%∼20% K doping correspond to 3.963 Å∼3.967 Å, and Mg and K codoping make lattice parameters increase from 3.967 Å to 3.974 Å. Mg2+ ion and K+ ion show acceptor doped mechanisms, Mg doping makes grains refine, and K doping makes grains grow. Pure BST powder and Mg doped BST powder show uniform grains with unclear grain boundaries, K doped BST powders can obtain uniform and dispersive grains with clear grain boundaries, but Mg and K codoping makes the uniformity and dispersity of the powders getting worse. Compared to pure BST powder, Mg doped BST powder shows smaller but more stable dielectric constant and dielectric loss, K doped powders tend to reveal larger and less stable dielectric constants and dielectric losses. Mg and K codoped BST powders show less than 35 dielectric constants, and lower than 0.02 dielectric losses. Dielectric properties are strongly dependent on the crystallization, doped mechanism and morphology. Mg doped and 2% Mg 2% K and 2% Mg 5% K codoped BST powders show low and stable dielectric constants and dielectric losses, thus can meet the requirements for tunable microwave applications and other applications.

Effect of SiO2 on dielectric properties of core-shell Sr and Tm co-doped BaTiO3@SiO2 ceramics

Sr and Tm co-doped Ba0.7Sr0.3Ti0.9925Tm0.01O3 (BST) and core-shell structured BST@SiO2 ceramics were prepared by sol-gel method and conventional sintering. Along with the obvious perovskite phases in the BST and BST@SiO2 powders, a new phase, Ba2TiSi2O8, was confirmed in the sintered BST@SiO2 bulk by XRD analysis. TEM analysis revealed that the BST powders were coated with an amorphous SiO2 film, while SEM analysis indicated that the SiO2 film plays a role in grain size reduction. The dielectric losses of BST@SiO2 ceramics reduced effectively compared to that of BST. In addition, the Curie peak of the BST@1%SiO2 ceramic significantly broadened and the Curie temperature shifted toward lower temperatures; this provides a new approach to improving the dielectric properties of BaTiO3 ceramics.

Synthesis and Characterization of Fe and Ni Co-Doped Ba0.6Sr0.4Tio3Prepared by Sol-Gel Technique

In this research work, Influence of Fe and Ni dopant on structural Ba0.6Sr0.4TiO3 nanocrystalline was studied. The pure and (Fe and Ni)-doped Ba0.6Sr0.4TiO3 (Ba1-xSrxTiO3, where (x=0.4), Ba1-xSrxTi1-yFeyO3, where (x=0.4, y=0.1) and Ba1-xSrxTi1-yNiyO3, where (x=0.4, y=0.1)) in powder, abbreviated as (BST), (BSTF) and (BSTN), respectively were prepared by a modified Sol-gel technique. In this process, stoichiometric proportions of barium acetate and strontium acetate were dissolved in acetic acid and titanium (IV) isopropoxide was added to form BST gel. The as-formed gels were dried at 200°C and then calcined at 850°C for crystallization. In order to improved crystallization, surface morphology and optimized grain size used Fe+3 and Ni2+ ions. Samples were characterized by Infrared spectroscopy method (FT-IR), UV-Visible spectroscopy, X-Ray Diffraction technique (XRD), Field Emission Scanning Electron Microscope (FESEM) and Energy Dispersive X-Ray Spectroscopy (EDS). The Nano-scale presence and the formation of the cubic perovskite phase as well as the crystallinity were detected using the mentioned techniques. The results showed that, the adding Fe and Ni to BST structure lead to decrease of the average size of nanoparticles and change the optical properties of the BST. The nanocrystallite sizes obtained were nearly 38, 37 and 34 nm, for BST, BSTF and BSTN powders calcined at 850°C, respectively.

Elucidating the effects of high temperature mixing method under hydrothermal condition (HTMM) on grain refinements and assembling structures

Crystal size and microstructure are of great importance in determining the physical and chemical properties of functional materials, and refine powders, especially their assembled porous structures have potential application in ceramic fabrication, absorption, catalysts and drug delivery, due to their characters of high activity and large specific surface area. Herein, high temperature mixing method under hydrothermal condition (HTMM) was adapted to synthesize barium strontium titanate [(Ba, Sr)TiO3, BST] powders with various Ba/Sr ratios (x=0.5, 1.0, 3.0 and 4.0). In comparison with conventional hydrothermal synthesis (CHS), the effects of HTMM on grain refinement and porous structure formation were exclusively investigated. XRD and SEM results indicated that, in the given condition, BST powders prepared by HTMM were much smaller than that by CHS, especially at a lower Ba/Sr ratio. Additionally, assembled porous architectures were constructed by HTMM. It's believed that the high temperature mixing process and continuous rotation contributed to the grain refinement and assembled porous structure, respectively. The assumption was further confirmed through the synthesis of sodium niobate (NaNbO3) powders by HTMM. It's demonstrated that HTMM is advantageous in preparation of refine powders and porous assembled architectures.

Dielectric and mechanical properties of poly(butylene succinate) thin film composites incorporated with barium strontium titanate powder

ABSTRACTHigh dielectric constant barium strontium titanate (Ba0.7Sr0.3TiO3 or BST) powder was prepared by sol-gel method for using as a filler in poly(butylene succinate) (PBS) composite with 0–3 connectivity system. Moreover, thermal and dielectric properties of poly(butylene succinate) integrated with BST powder were studied. The results showed the success of improving thermal stability and dielectric constant of poly(butylene-succinate) by increasing amount of BST powder. Therefore, the prepared PBS-BST composite thin films with good dielectric properties, flexibility, and processability could be applicable for the thin film capacitor for high-frequency electronic devices.

Structural and dielectric properties of Bi-doped barium strontium titanate nanopowders synthesized by sol–gel method

Nano-crystalline barium strontium titanate, Ba0.5Sr0.5TiO3, (BST) powders were synthesized by sol–gel method, and the effects of Bi-doped on the microstructure and dielectric properties of BST powders were investigated. At first, the stable BST sols with optimum molar ratio were prepared and then different precents of bismuth were doped in precursor solutions. The samples, after drying and calcination at 850°C for 2h, were characterized by TG-DTA, FTIR, XRD, FESEM and LCR meter equipments. The results showed that the crystallite size and lattice parameter changed by increasing doped Bi content of BST. Also, with increasing Bi content from 2 to 4mol%, average particle size of BSTB decreased from 40 to 35nm. The dielectric constant for all samples increased with increasing calcination temperatures and then decreased after Curie temperature. An increase in the dielectric constant was observed up to a maximum of 1040 at a temperature of 80°C for BSTB2 and 910 at 70°C for BSTB4, approximately. The maximum value of dielectric constant and dielectric loss of the Bi-doped BST ceramics decreased with increasing Bi content.

Effect of cerium doped concentration on grain growing modes of BST powder

ABSTRACTCerium (Ce) doped barium strontium titanate (Ce-BST) powder was prepared by sol-gel method, and the effect of Ce doped concentration on growing modes of grains of the Ce-BST powder was studied. X-ray diffraction (XRD) reveals that all Ce-BST powders show cubic perovskite structures. It can be found that increasing Ce doped concentration corresponds to decreasing lattice parameter until the doped concentration increases to 3% mol ratio, and then the continuingly increasing doped concentration corresponds to increasing lattice parameter. Scanning electron microscopy (SEM) exhibits that all powders are composed of nano-grains, but the growing modes of the grains strongly depend on the doped concentration. When doped concentration is not more than 1% mol ratio, the grains show globular growth; when the doped concentration is not less than 3% mol ratio, the grains show layered growth; when the doped concentration ranges from 1% mol ratio to 3% mol ratio, columnar grains appear in the globular powders. Also, the dielectric properties of the powders are presented and the related mechanisms are discussed.

The Effect of the Firing Conditions on the Properties of Barium Strontium Titanate Powders Prepared by Sol-Gel Combustion Method Using Citric Acid as Fuel

Barium strontium titanate (Ba0.7Sr0.3TiO3; BST) powders were prepared via sol-gel combustion method using citric acid as fuel. The molar ratio of sol powder: fuel = 1:1. All of the samples were calcined at 450–950°C for 2, 3 and 4 hours. The crystallinity of the powders was improved by increasing the calcination temperature indicated by the increasing of the perovskite peak intensity from the X-rays diffraction analysis. The pure perovskite phases were crystalline at temperature 750°C with calcination time 2, 3 and 4 hours, after that BST powders were applied with acid treatment process. The XRD result showed that the pure perovskite phase without the phase of pyrochlore in all of the samples.BST is in cubic structure, corresponding to JCPDS 34–0411. The morphology and microstructure of synthesized BST powders were analyzed by a scanning electron microscope (SEM). The particles were agglomerated, spherical shape and were larger corresponding with the increasing of calcination temperature and dwelling time. The average of particle size was about 50–115 nm.

Structure and Dielectric Properties of Lead-Free BaSn0.1Ti0.9O3-BaFe0.5Nb0.5O3 Ceramics

Binary solid solutions of the (1-x)BaSn0.1Ti0.9O3-xBaFe0.5Nb0.5O3 system, with x = 0, 0.05, 0.10, 0.15 and 0.20 were prepared via a solid-state processing technique. The BST and BFN powders were synthesized separately using a calcination technique with optimum temperature. XRD results revealed that the structures of the BST-BFN ceramics were of tetragonal symmetry and the tetragonality (c/a ratio) decreased with increasing BFN content. BFN caused enhanced dielectric constant of BST ceramics that increased with temperature. The highest dielectric constant was ∼120000 for x = 0.20 at temperature of 400°C (1 kHz).

Effect of carbon-dopant on the optical band gap and photoluminescence properties of [Ba0.5Sr0.5]TiO3 powders synthesized by the sol–gel process

In this paper we studied the effect of carbon-doped on the optical band gap and photoluminescence properties of barium strontium titanate powders, [Ba0.5Sr0.5]TiO3 (BST), that synthesized via the sol–gel process with internal carbon sources, i.e., methanol, ethanol, and 1-butanol acting as a solvent. The types of solvent governed on the in-gap mechanism of C-doped BST powders. The Ti4+ ions substitution with partial C4+ ions was clearly proved by Fourier transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy (XPS). As-synthesized pure BST powders were less weight losses and the carbonate species not observed. Indirect band gap of BST powders was examined by ultraviolet–visible spectroscopy. A possible in-gap mechanism between valence band maximum and conduction band minimum of BST powders was investigated by photoluminescence (PL) behavior. The PL emissions of pure BST powders appeared in five processes at 3.15, 2.95, 2.80, 2.55 and 2.33eV, whereas the C-doped BST powder did not appear at 2.95eV. Since the strong interaction of C–O bonds appeared that have been shared electrons of OåCåO bonds rather than transferred in the octahedral [TiO6] clusters. XPS and electron paramagnetic resonance spectra revealed the amount of oxygen deficiency was considerably formed by the long chain alcohol, while the short chain alcohol exhibited low amount. Besides that, (Ba+Sr)/Ti and (TiO5–VOX)/(TiO6) ratio increased gradually as molecular weight of alcohol.

Effects of sintering temperature on the properties of donor-acceptor codoped Ba0.67Sr0.33TiO3 ceramics for pyroelectric infrared detector applications

Ba0.67−xYxSr0.33Ti1−yMnyO3 [(Mn+Y: BST), x=0.006, y=0.005] ceramics were fabricated via using citrate–nitrate combustion derived powder, and their microstructure, dielectric properties and pyroelectric properties were systemically investigated within sintering temperature ranged from 1200°C to 1310°C. Slight agglomerated BST powders, with nano-size parties, were produced at calcining temperature of 800°C. Sintering temperature has a great influence on the microstructure and electrical properties of the ceramic samples. The dielectric and pyroelectric properties are improved with sintering temperature increased from 1200°C to 1280°C. At room temperature, the Mn+Y: BST ceramics sintered at 1280°C for 3h exhibit optimal electrical properties: dielectric loss tanδ=0.007, intrinsic pyroelectric coefficient γ=773nC/cm2K and figure-of-merit FD=134.5μPa−0.5 at 100Hz, respectively. Improvement of pyroelectric properties is beneficial to the development of infrared detectors.

Effect of the Fuel Type on the Synthesis of Barium Strontium Titanate by Sol-Gel Combustion Method

The ferroelectric ceramic, Barium Strontium Tinanate (Ba0.7Sr0.3TiO3), was prepared by the sol-gel combustion method using citric acid, urea, and glycine as the fuel for reduce the calcination temperature. The molar ratio of sol powderto fuel was 1:1. All of the samples were calcined at 450, 550, 650, 750, 850 and 950°C for 2 h. Then,Ba0.7Sr0.3TiO3powders were applied with acid treatment process. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscope (TEM) analysis were used to characterize the crystal structure and microstructure. The perovskite phases of BST and the pyrochlore (BaCO3,SrCO3) were obtained after the calcinations temperature of 550°C. BST powders were applied with acid treatment process.The XRD result showed the pure perovskite phase without the phase of pyrochlore in all of the samples. Ba0.7Sr0.3TiO3was in cubic structure, corresponding to JCPDS 34-0411. SEM analysis of BST powders calcined at 750°C.The particles were spherical morphology and had agglomerates while the particles sizes were larger corresponding with the increase of calcinations temperature.The results for TEM analysis of the BST powders prepared by using urea as the fuel had a smaller particles,and the average of particle size was about 47 nm.

Effect of Na-, K-, Mg-, and Ga dopants in A/B-sites on the optical band gap and photoluminescence behavior of [Ba0.5Sr0.5]TiO3 powders

In this work, the role of the representative metal dopants (Na, K, Mg and Ga) in A/B-sites of [Ba0.5Sr0.5]TiO3 powders (in short BST) synthesized by sol–gel method have been investigated. As revealed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV–visible spectroscopy, Na and K can be occupied into A-site, while Mg and Ga can be substituted on B-site of BST powders. It was found that the optical band gap energies of modified B-site are higher than modified A-site of BST powders. The possible mechanisms of intermediate energy levels between optical band gaps were suggested by photoluminescence (PL) behavior. The four major optical emissions in visible range were found to be 2.95, 2.80, 2.55, and 2.33eV. The 2.95eV in violet PL emissions is related to the electron transfer in octahedral [TiO6] clusters. Moreover, this energy level is attributed to the charge compensation process due to acceptor substitution defects in order to preserve the overall charge neutrality in the BST crystal. The 2.85eV in blue PL emissions is attributed to the fully-ionized oxygen vacancy (VO••) in BST powders. The 2.55 and 2.33eV in green PL emission are assigned to the charge-transfer of singly-ionized oxygen vacancy (VO•) and the charge transfer vibronic excitons (CTVE) in BST perovskite, respectively. In additional, as revealed by electron paramagnetic resonance (EPR), modified B-site of BST powders facilitated titanium vacancy more than modified A-site. The X-ray photoelectron spectroscopy (XPS) results indicated that modified B-site of BST powders were easily created oxygen deficiency than modified A-site. However, the oxygen deficiency significantly affected on A-site of the Sr atoms site more than A-site of the Ba atoms, it might be a result of the strength of chemical bond of Sr–O bonds which is lower than Ba–O bonds.