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Lead-free piezoelectric (K, Na)NbO3 (KNN) is considered one of the promising candidates for the replacement of Pb(ZrxTi1−x)O3. Several studies underlined the issue of K and Na volatility with increasing deposition temperatures, leading to high leakage currents in thin films, which still represents a major drawback for applications. This paper shows how epitaxial growth with concomitant preferred orientation of KNN films on niobium-doped strontium titanate (Nb:STO) depends on growth temperature and substrate strain. A preferred out-of-plane polar (001) orientation of KNN is obtained at high temperatures (>600 °C), while (100) orientation is dominant for lower ones. The (001) orientation is forced out-of-plane due to the sizeable in-plane stress derived from a negative lattice mismatch of pseudo-cubic KNN with respect to the underlying cubic (001) Nb:STO substrate. Moreover, we show that K-Na deficiency and high leakage of epitaxial KNN films deposited at high temperatures are accompanied by the appearance of a pattern of orthogonal spontaneous ferroelectric domains aligned to the [100] and [010] directions of Nb:STO. This pattern, visible in secondary electron microscopy, piezoforce response microscopy, and conductive atomic force microscopy images, is uncorrelated to the surface morphology. Supported by reciprocal space mapping by x-ray diffraction, this phenomenon is interpreted as the result of strain relaxation via ferroelectric domain formation related to K-Na deficient films displaying a sizable and increasing compressive strain when grown on Nb:SrTiO3. Our findings suggest that strain engineering strategies in thin films could be used to stabilize specific configurations of piezo- and ferroelectric domains. [ABSTRACT FROM AUTHOR]

Polymeric composite materials are in great demand in biomedical and water treatment applications. This is because they possess distinct characteristics and can fulfill specific biomedical needs, in addition to their ability to degrade dyes. This study successfully synthesized sustainable strontium titanate (STO) particles with an average size of 120 nm using the solid-state method. When these STO particles were mixed into a PCL-based polyurethane matrix, the matrix became hydrophilic with a contact angle of 58.60° and its mechanical strength enhanced by 320%. The morphology and surface roughness of the films were determined using FESEM and AFM techniques. The antibacterial studies of polymeric composites film against E. coli, Klebsiella pneumonia, and S. aureus , showing good zone growth, and showing enhanced swelling properties of 270% for wound healing and biomedical applications. The photocatalytic performance of the STO by degrading Methyl Orange (MO) and Congo Red (CR) under UV light, achieving degradation efficiencies of 92.25% for MO and 62.5% for CR over 150 min. These findings suggest that PU scaffolds and STO are suitable for biological and water treatment in industrial applications. [Display omitted] [ABSTRACT FROM AUTHOR]

The oxide surface structure plays a vital role in controlling and utilizing the emergent phenomena occurring at the interface of nanoarchitecture. A complete understanding of ternary oxide surfaces remains challenging due to complex surface reconstructions in various chemical and physical environments. Here a thermodynamic framework is developed to treat the stability of ternary oxide surfaces with finite temperature and chemical environments. Strontium titanate, as a representative ternary oxide, is used to establish the complete energy landscape of SrTiO3 (001) surface. The complete mapping yields a comprehensive understanding of various stable SrTiO3 surfaces with finite temperature and chemical potential or vapor pressure of the constituents, i.e., Sr (or Ti) metal and oxygen. This treatment also reveals a stable surface unknown yet with SrTi2O3 stoichiometry, which unveils the missing link between numerous previous experimental observations and the current understanding of SrTiO3 surface. Interestingly, the new surface shows an anisotropic surface‐localized metallic state originating from the characteristic surface structure. The findings would provide a viable way to understand ternary oxide surfaces and further utilize SrTiO3 surfaces for oxide nanoarchitectures. [ABSTRACT FROM AUTHOR]

To address the risk of bacterial infection during the early implantation of medical titanium implants, this study designed a strontium barium titanate rod-like silver coating with piezoelectric effect. The antibacterial properties of nano-silver, the spiky structure of the rod-like array, and the piezoelectric effect were utilized to achieve rapid and continuous bactericidal effects in the early stages. The surface morphology and microstructure of the coating were analyzed, along with an examination of its phase composition and silver element distribution. Furthermore, investigations into the impact of silver loading on wetting angle and piezoelectric coefficient were conducted, as well as tests on the cumulative release of silver ions. Bacterial experiments confirmed that even after 7 days immersed in PBS, the antibacterial rate for barium strontium titanate rod-like silver coated titanium surfaces with piezoelectric effect remained at 99.99 %, slightly higher than unpolarized coatings. Finally, assessments on toxicity, proliferation, and adhesion of osteoblasts revealed excellent performance from polarized coatings. These results provide data support and a theoretical basis for studying the antibacterial effects of piezoelectricity in conjunction with other antibacterial strategies. [ABSTRACT FROM AUTHOR]

Amidst the swift expansion of the electric vehicle industry, the imperative for alternative battery technologies that balance economic feasibility with sustainability has reached unprecedented importance. Herein, we utilized Perovskite-based oxide compounds barium titanate (BaTiO3) and strontium titanate (SrTiO3) nanoparticles as anode materials for lithium-ion batteries from straightforward and standard carbonate-based electrolyte with 10% fluoroethylene carbonate (FEC) additive [1M LiPF6 (1:1 EC: DEC) + 10% FEC]. SrTiO3 and BaTiO3 electrodes can deliver a high specific capacity of 80 mA h g−1 at a safe and low average working potential of ≈0.6 V vs. Li/Li+ with excellent high-rate performance with specific capacity of ~90 mA h g−1 at low current density of 20 mA g−1 and specific capacity of ~80 mA h g−1 for over 500 cycles at high current density of 100 mA g−1. Our findings pave the way for the direct utilization of perovskite-type materials as anode materials in Li-ion batteries due to their promising potential for Li+ ion storage. This investigation addresses the escalating market demands in a sustainable manner and opens avenues for the investigation of diverse perovskite oxides as advanced anodes for next-generation metal-ion batteries. [ABSTRACT FROM AUTHOR]

This study investigates the influence of thermal history on grain boundary (GB) energy and the grain growth behavior of SrTiO3 at 1425°C. Two thermal profiles were explored: (1) a single‐step sintering at 1425°C for 1 h and (2) a two‐step profile with sintering completed at 1425°C for 1 h with an additional 10 h at 1350°C. Electron backscattered diffraction and atomic force microscopy were utilized to measure the grain size and GB energy distributions, respectively, for the samples before and after grain growth at 1425°C for 10 h. The two‐step profile exhibits fewer abnormal grains and a slower growth rate at 1425°C than the single‐step profile. Additionally, the two‐step sample comprises few high‐energy GBs and a narrow GB energy distribution, which suggests that it had a lower driving force for subsequent grain growth. The thermal profile was able to sufficiently change the growth rate such that the two‐step sample results in a finer grain size than observed for the single‐step sample after 10 h at 1425°C despite being exposed to elevated temperatures for almost twice as long. These results suggest that GB energy engineering through thermal profile modification can be used to control the grain growth rate and abnormal grain growth likelihood. [ABSTRACT FROM AUTHOR]

A novel organic-inorganic photocatalyst like layer structured graphitic carbon nitride (g-C3N4 or CN) hybrid with strontium titanate (SrTiO3 or STO) was prepared by a precipitation-sonication technique for photocatalytic activity. The crystal phases, morphologies, elemental composition, optical properties, and porous structure of the prepared pristine and STO/CN hybrid composite were measured using various physicochemical characterizations. It is indicated that STO nanospheres were effectively loaded on the g-C3N4 nanosheets, resulting in the STO/CN hybrid composite, high surface area, enhanced visible-light absorption, enhancing photoinduced charge separation and suppressing the recombination rate. Furthermore, the 3 wt% of g-C3N4 composited STO (STO/CN-3) catalyst demonstrated higher photocatalytic activity than pristine STO in 100 min under white light irradiation, reaching the degradation efficiency of 92.66 % and 93.31 % toward methylene blue (MB) and tetracycline (TC), respectively. The improved photocatalytic activity of STO/gCN hybrid composite could be ascribed to the synergistic effect between STO and CN with strong interfacial interaction facilitating efficient charge separation and inhibiting the charge recombination of photogenerated electron-hole pairs. Moreover, a possible photocatalytic mechanism has been proposed for the degradation of MB and TC. Besides, the excellent photocatalytic performance, STO/CN-3 nanocomposite also exhibits outstanding photostability under the current factors, suggesting that they are suitable for practical applications. [ABSTRACT FROM AUTHOR]

Thin films of strontium titanate, which reveal high structure quality and tunable properties prospective for microwave applications at room temperature, were grown on a semi-insulating silicon carbide substrate using magnetron sputtering for the first time. The films' growth mechanisms were studied using medium-energy ion scattering, and the films' structures were investigated using X-ray diffraction. The electrical characteristics of planar capacitors based on strontium titanate films were measured at a frequency of 2 GHz using a high-precision resonance technique. It is shown that the tendency to improve the crystalline structure of strontium titanate film with an increase in the substrate temperature is most pronounced for films deposited at elevated working gas pressure under low supersaturation conditions. Planar capacitors formed on the basis of oriented SrTiO3 films on silicon carbide showed tunability n = 36%, with a loss tangent of 0.008–0.009 at a level of slow relaxation of capacitance, which is significantly lower than the data published currently regarding planar tunable ferroelectric elements. This is the first successful attempt to realize a planar SrTiO3 capacitor on a silicon carbide substrate, which exhibits a commutation quality factor more than 2500 at microwaves. [ABSTRACT FROM AUTHOR]

This study investigates the influence of thermal history on grain boundary (GB) energy and the grain growth behavior of SrTiO3 at 1425°C. Two thermal profiles were explored: (1) a single‐step sintering at 1425°C for 1 h and (2) a two‐step profile with sintering completed at 1425°C for 1 h with an additional 10 h at 1350°C. Electron backscattered diffraction and atomic force microscopy were utilized to measure the grain size and GB energy distributions, respectively, for the samples before and after grain growth at 1425°C for 10 h. The two‐step profile exhibits fewer abnormal grains and a slower growth rate at 1425°C than the single‐step profile. Additionally, the two‐step sample comprises few high‐energy GBs and a narrow GB energy distribution, which suggests that it had a lower driving force for subsequent grain growth. The thermal profile was able to sufficiently change the growth rate such that the two‐step sample results in a finer grain size than observed for the single‐step sample after 10 h at 1425°C despite being exposed to elevated temperatures for almost twice as long. These results suggest that GB energy engineering through thermal profile modification can be used to control the grain growth rate and abnormal grain growth likelihood. [ABSTRACT FROM AUTHOR]

Flash events, which are electric power spikes occurring under an electric field and temperature above the threshold, can significantly accelerate mass diffusion over short periods of time. This study investigated the surface structure of the (001) surface of strontium titanate single-crystal treated by flash events caused by direct current (DC) and alternating current (AC) electric fields from a viewpoint of surface-related mass diffusion. The surface structuring caused by flash events was significantly different among DC and AC electric fields. The DC-flash event destabilized surface steps, causing them to wander and form surface mounds with a height of several tens of nanometers. In addition, numerous two-dimensional (2D) nuclei with a size of several nanometers are formed on the terraces. In contrast, the AC-flash event stabilized surface steps without the formation of surface mounds, causing them nearly straight with uniform terrace width at approximately 500 nm. 2D nuclei with a size of a few 10 nm were formed at the step edges with round shapes. Both methods were confirmed as evidenced by the formation of two-dimensional nuclei on the surface after the flash events, to enhance surface-related mass diffusion. [ABSTRACT FROM AUTHOR]

Strontium titanate (STO) and its variants have emerged as leading materials in photocatalysis, particularly for degrading nitrogen oxides (NOx), due to their non-toxic nature, structural adaptability, and exceptional thermal stability. Although the one-pot sol-gel method leads to high-quality photocatalysts, areas remain for improvement. This study examines the impact of ethanol as a cosolvent in STO synthesis, focusing on optimizing the water-to-ethanol volume ratio. The findings reveal that a 1:3 ratio significantly enhances macropore formation and photocatalytic efficiency, achieving 42% NOx degradation under LED within three hours. Furthermore, incorporating 8.0 wt.% Ag into STO substantially improves visible light absorption and enables complete NOx elimination, thanks to enhanced charge separation and localized surface plasmon resonance. Even at high temperatures (1100 °C), the Ag-STO photocatalyst maintains partial activity, despite exceeding silver's melting point. These results highlight the potential of STO-based materials for industrial applications, positioning them as a promising solution for effective NOx mitigation. [ABSTRACT FROM AUTHOR]

Dislocations are being used to tune versatile mechanical and functional properties in oxides with most current studies focusing on single crystals. For potentially wider applications, polycrystalline ceramics are of concern, provided that dislocations can be successfully introduced. However, in addition to preexisting pores and flaws, a major barrier for bulk plastic deformation of polycrystalline ceramics lies in the grain boundaries (GBs), which can lead to dislocation pile‐up and cracking at the GBs due to the lack of sufficient independent slip systems in ceramics at room temperature. Here, we use the cyclic Brinell indentation method to circumvent the bulk deformation and focus on near‐surface regions to investigate the plastic deformation of polycrystalline SrTiO3 at room temperature. Dislocation etch‐pit analysis suggests that plastic deformation can be initiated within the grains, at the GBs, and from the GB triple junction pores. The deformability of the individual grains is found to be dependent on the number of cycles, as also independently evidenced on single‐crystal SrTiO3 with representative surface orientations (001), (011), and (111). We also identify a grain‐size‐dependent plastic deformation. [ABSTRACT FROM AUTHOR]

Current work focuses on the potential of atmospheric agents such as gamma rays and plasma on conventional solar cell efficiency. Improving the device performance by depositing a ZnO or SrTiO 3 layer on the front surface of both monocrystalline and polycrystalline Si cells has been achieved. The electrical parameters detected by measuring the I-V characteristic are discussed. The results were analyzed using modified thermal emission theory to estimate the barrier height (Bo), ideality factor (n), series resistance (Rs) and shunt resistances (Rsh). Gamma irradiation at 1 kGy increased the open circuit voltage (V OC), the short circuit current (I sc), the voltage maximum point (V mp) and the current maximum point (I mp) , hence the maximum output power (P m) and efficiency (η) of both cell types. Concerning the dense plasma focus (DPF), the effect of H2 gas flow was found to increase the efficiency by 16.5 % and 22.5 %, respectively for mono and poly cells. The potential effect of the thin layer SrTiO3 (SrTiO3/Si) or ZnO (ZnO/Si) was recorded to lead to efficiency improvement of 24 % and 23 %, respectively for mono cells. Also, through SEM images, the morphology of the oxide surface was examined. The effect of light trapping and the reduction of recombination by the front layer in both SrTiO3/Si and ZuO/So cells on the PV performance and the role played by grain boundaries in polycrystalline cells were discussed. [ABSTRACT FROM AUTHOR]

New technologies of microelectronics are emerging to reduce the size of devices and combine them into more compact ultralow power systems. Betavoltaic power sources (BVPSs) can serve as power generators of such order. BVPSs consist of a combination of betavoltaic cells (BVCs) based on long-lived radioisotopes of beta radiation and semiconductor converters (SCs). One of the key tasks for increasing the power of BVCs is the selection of SCs that can efficiently convert the energy of beta particles into electricity. Currently, semiconductor structures with a developed surface and a high band gap are considered to be perspective SCs. In present work, arrays of titanium dioxide nanopores (TiO2 NPs) synthesized by common electrochemical anodization were chosen as a SCs. These SCs were part of BVCs based on nickel-63 with an activity of ~10 Ci/g. TiO2 NPs with an amorphous structure in the composition of BVC demonstrated low electrical parameters. To increase them, we modified TiO2 NPs by the hydrothermal method in a solution of Sr(OH)2 with a concentration of 0.05 mol/L at various times. These experiments were carried out in order to convert TiO2 (anatase) into structure-like SrTiO3. We found that the electrical parameters of the SCs increased with the duration of the modification time. The best result was obtained in the case of modification for 3 h—the BVC generated a short circuit current of 2.9 nA and open circuit voltage of 0.8 V and had a maximum power of 0.8 nW at 0.45—0.5 V. The obtained electrical parameters in combination with the miniature dimensions of the BVCs open up the potential possibility of creating a BVPS with an increased power density. [ABSTRACT FROM AUTHOR]

Traditionally, Fischer–Tropsch (FT) synthesis is performed using thermal catalysts and syngas (CO and H2) under high‐pressure and high‐temperature conditions. However, this study introduces an approach that relies on FT chemistry assisted by electrochemistry, referred to here as direct electrochemical (EC) FT chemistry, under ambient conditions. A series of CH4, CnH2n, and CnH2n+2 hydrocarbons (n = 1–7) is successfully produced over gold (Au) nanoparticle‐loaded perovskite strontium titanate (SrTiO3) nanostructures grown on rutile TiO2 supported on Ti. Au (1.0 nm)–SrTiO3 shows the best interface formation, with the highest Faradaic efficiency for C2+ hydrocarbons. This direct EC‐FT process proceeds via a C─C coupling chain growth reaction at the Au‐SrTiO3 interface as evidenced by the hydrocarbon weight distribution analysis and density functional theory calculations. The robust combination of experimental and computational findings reveals that optimum conditions for producing surface hydrogenation and C─C coupling polymerization, initiated by surface *CO and *H are achieved by controlling the undercoordinated Au at the perimeter sites of supported Au nanoparticles and by ensuring a harmonized density of states between Au and SrTiO3. This EC‐FT process opens a promising avenue for the direct conversion of CO2 and H2O into value‐added long‐chain hydrocarbons. [ABSTRACT FROM AUTHOR]

A syngas was generated at a near-unity H2/CO ratio independent of the reactant gas composition over Rh-loaded strontium titanate in the photo-induced dry reforming of methane. Moreover, light irradiation inhibited side reactions, such as the reverse water gas shift reaction and the precipitation of the solid-state carbon. These results were not explained by thermodynamic equilibrium, but were presumably owing to the unique effect of the photogenerated electron–hole pairs. [ABSTRACT FROM AUTHOR]

Directly crystallizing strontium titanate (SrTiO 3) nanoparticles from a solution near room temperature poses a challenge due to Ti ions easily form colloids and result in amorphous products. It is also difficult to ensure the uniform incorporation of the dopants into the lattice during synthesis of doped samples. This study successfully achieved this task using the direct synthesis from solution (DSS) method. Both undoped SrTiO 3 nanoparticles and Fe-doped one were synthesized in an ethanol solution at the temperatures ranging from 60 to 80 °C, resulting in homogeneous grains with an average size of approximately 15 nm. Despite the solubility limit of Fe3+ in bulk SrTiO 3 being around 2.5 %, we successfully synthesized Fe-doped SrTiO 3 nanocrystals with high doping level even at a dose of 10 %. The tribocatalytic performance of both undoped and Fe-doped SrTiO 3 nanoparticles was evaluated for methylene blue degradation in a solution. Undoped SrTiO 3 nanoparticles showed similar catalytic performance to P25. In contrast, Fe-doped SrTiO 3 nanoparticles exhibited much higher catalytic performance. This enhanced catalytic performance is attributed to the presence of oxygen vacancies, which are introduced by doping Fe3+ into the SrTiO 3 lattice to substitute the Ti ion. [ABSTRACT FROM AUTHOR]

This research was focused on the influence of manganese (Mn) incorporation at Sr and/or Ti sites on the microstructure, relative dielectric permittivity and specific magnetization of strontium titanate (SrTiO 3) ceramics. A solid-state method was used for the preparation of mechanically activated (10, 30 and 120 min) Mn-doped SrTiO 3 ceramics with various manganese dioxide (MnO 2) weight percentages (1.5, 3 and 6 wt%). Rietveld's analysis showed that the mean crystallite size in doped-activated SrTiO 3 ceramics is smaller than in undoped ceramics, which is a consequence of additional crystal structure distortion due to ion substitution. Changes in the Raman spectra indicated dopant incorporation in the SrTiO 3 lattice. The microstructural analysis pointed out a decrease in the mean grain size with increasing dopant concentration and time of activation. The highest values of permittivity and magnetization were observed for Mn-doped SrTiO 3 ceramic mechanically activated for 120 min. Based on all the above, the optimal electrical and magnetic properties of SrTiO 3 ceramics can be achieved by the appropriate choice of mechanical activation time and dopant concentration. [ABSTRACT FROM AUTHOR]

Magnetic and ferroelectric oxide thin films have long been studied for their applications in electronics, optics, and sensors. The properties of these oxide thin films are highly dependent on the film growth quality and conditions. To maximize the film quality, epitaxial oxide thin films are frequently grown on single‐crystal oxide substrates such as strontium titanate (SrTiO3) and lanthanum aluminate (LaAlO3) to satisfy lattice matching and minimize defect formation. However, these single‐crystal oxide substrates cannot readily be used in practical applications due to their high cost, limited availability, and small wafer sizes. One leading solution to this challenge is film transfer. In this demonstration, a material from a new class of multiferroic oxides is selected, namely bismuth‐based layered oxides, for the transfer. A water‐soluble sacrificial layer of Sr3Al2O6 is inserted between the oxide substrate and the film, enabling the release of the film from the original substrate onto a polymer support layer. The films are transferred onto new substrates of silicon and lithium niobate (LiNbO3) and the polymer layer is removed. These substrates allow for the future design of electronic and optical devices as well as sensors using this new group of multiferroic layered oxide films. [ABSTRACT FROM AUTHOR]

This work develops a polarization-dependent analytical model using terahertz time-domain spectroscopy (THz-TDS) for computing strain in materials. The model establishes a correlation between volumetric strain and the change in time of arrival for a THz pulse by using the dielectrostrictive properties, variations in doping particle density, and changes in the thickness of the sample resulting from Poisson's effects. The analytical model is validated through strain mapping of polydimethylsiloxane (PDMS) doped with passive highly dielectrostrictive strontium titanate (STO). Two experiments, using an open-hole tensile and a circular edge-notch specimen are conducted to show the efficacy of the proposed. The stress relaxation behavior of the composite is measured and accounted for to prevent changes in strain during the measurement window. The THz strain mapping results are compared with the finite element model (FEM) and surface strain measurements using the digital image correlation (DIC) method. The experimental findings exhibit sensitivity to material features such as particle clumping and edge effects. The THz strain map shows a strong agreement with FEM and DIC results, thus demonstrating the applicability of this technique for surface and sub-surface strain mapping in polymeric composites. [ABSTRACT FROM AUTHOR]

Photochemical cathodic protection represents a burgeoning, eco-friendly, and pollution-free technology for metal preservation. Strontium titanate (SrTiO3), a semiconductor material distinguished by its unique band structure, is particularly well suited for applications in photoelectrochemical cathodic protection. Addressing its limitations through the strategic doping of two nonmetal elements can significantly enhance its photoelectrochemical attributes. In this study, a flower-ball morphology of SrTiO3 was synthesized via a hydrothermal process. The material was subsequently co-doped with nitrogen and fluorine, sourced from ammonium chloride and sodium fluoride, respectively. This co-doping process was applied to protect 304 stainless steel under a simulated sunlight environment with N/F-x%-SrTiO3. The outcomes of the experiment demonstrated the successful incorporation of N and F into the SrTiO3 crystal lattice. The photoanode composed of SrTiO3 doped with 2% F and 3% N exhibited superior photochemical cathodic protection capabilities. It achieved a photocurrent density of 6.0 μA/cm2, and the open-circuit potential shifted negatively to −0.46 V. The co-doping modification with N and F facilitated the formation of impurity energy levels within the bandgap of SrTiO3. This intervention effectively reduced the semiconductor's bandgap width, thereby increasing the material's sunlight utilization efficiency and bolstering its photochemical cathodic protection performance. This advancement marks a significant stride in the development of SrTiO3 for applications in metal protection and environmental sustainability. The application of co-doping techniques significantly enhances the photochemical cathodic protection properties of SrTiO3. By introducing nitrogen (N) and fluorine (F) into the SrTiO3 lattice, a novel impurity level is created just above the native valence band. The presence of this impurity level effectively narrows the bandgap of SrTiO3, leading to an increased absorption of sunlight and a consequent improvement in the utilization of solar energy. Under identical experimental conditions, the photocurrent density of the co-doped SrTiO3 achieves a remarkable 6 μA/cm2, which is a threefold increase compared to that of the undoped SrTiO3. Furthermore, the open-circuit potential of the doped material exhibits a more negative shift, reaching −0.46 V, a significant improvement of 60 mV over the pure SrTiO3. These enhancements underscore the effectiveness of the co-doping strategy in optimizing the material's performance for photochemical cathodic protection applications. [ABSTRACT FROM AUTHOR]

The aim of this work was to verify the possibility of forming Ni-Fe and Co-Fe alloys via topotactic ion exchange exsolution in Fe-infiltrated (La,Sr,Ce)0.9(Ni,Ti)O3-δ or (La,Sr,Ce)0.9(Co,Ti)O3-δ ceramics. For this purpose, samples were synthesized using the Pechini method and then infiltrated with an iron nitrate solution. The reduction process in dry H2 forced the topotactic ion exchange exsolution, leading to the formation of additional round-shape structures on the surfaces of grains. EDS scans and XRD analysis confirmed the formation of bimetallic alloys, which suggests that these materials have great potential for further use as anode materials for Solid Oxide Fuel Cells (SOFCs). [ABSTRACT FROM AUTHOR]

The aim of this work was to verify the possibility of forming Ni-Fe and Co-Fe alloys via topotactic ion exchange exsolution in Fe-infiltrated (La,Sr,Ce)0.9(Ni,Ti)O3-δ or (La,Sr,Ce)0.9(Co,Ti)O3-δ ceramics. For this purpose, samples were synthesized using the Pechini method and then infiltrated with an iron nitrate solution. The reduction process in dry H2 forced the topotactic ion exchange exsolution, leading to the formation of additional round-shape structures on the surfaces of grains. EDS scans and XRD analysis confirmed the formation of bimetallic alloys, which suggests that these materials have great potential for further use as anode materials for Solid Oxide Fuel Cells (SOFCs).

Pump-probe excitation technique using mid-infrared free electron laser and Nd:YVO4 ps-laser from Kyoto University free electron laser facility was implied to selectively excite a Raman inactive phonon mode of a semiconductor single crystal sample. The LO3 phonon mode of strontium titanate was chosen and the MIR-FEL photon energy was adjusted to match the target phonon mode energy, which corresponded to a wavelength of 12.5 µm. Temporal and spatial overlapping of MIR-FEL pulses and probe laser pulses were performed and confirmed through sum frequency generation from ZnS cleartran®. Confirmation of the Raman forbidden mode excitation was achieved through the anti-Stokes hyper-Raman scattering (ASHRS) spectroscopy method. Successful excitation was observed at 5 K, where thermal excitation of all other phonon modes was suppressed. The recorded spectrum showed a signal that was red-shifted from 800 to around 761 cm−1. The broadened line width (FWHM) and the red-shifting phenomenon in the recorded result have been observed due to the restraint of the spectrometer slit width function and the intense irradiation of the picosecond laser for hyper-Raman scattering spectroscopy, which have also led to surface damage on the crystal sample. [ABSTRACT FROM AUTHOR]

In the quaternary system PbTiO3-PbZrO3-SrTiO3-SrZrO3, compositions that lie close to the antiferroelectric tetragonal and ferroelectric rhombohedral (AFET-FER) phase boundary have potential applications in micro-actuators. However, in thin films, this phase boundary is reported to shift significantly to the zirconium-rich region. Hence, it is necessary to seek alternative approaches to stabilize the tetragonal AFE phase in such compositions. Therefore, this study explores the effect of B-site Mn3+-doping on their structure. Dielectric, ferroelectric, and piezoelectric characteristics of such thin films have been compared with those with increasing Zr/Ti ratios to understand the efficacy of this approach. Transverse piezoelectric coefficient, e31,f, and bipolar strain are found to be higher in Mn3+-doped thin films. Furthermore, large strains and e31,f in thin films have been correlated with structural modifications revealed by systematic Raman spectroscopic investigations. [ABSTRACT FROM AUTHOR]

Since acrylate‐based materials are widely used in dentistry, their drawbacks such as low impact resistance and hardness, require continuous research in the field of materials science in order to avoid sudden fracture caused by chewing or fall. In this study, auto‐polymerizing poly(methyl methacrylate) (PMMA), commonly used as denture base material, was reinforced with poly(4‐styrenesulfonic acid‐co‐maleic anhydride) sodium salt (PSSMA) and strontium titanate (STO), with the aim of improving impact behavior and microhardness. Morphological analysis confirmed formation of phase‐separated and co‐continuous microscopic structures of PSSMA in PMMA, without visible agglomerates of STO nanoparticles, indicating that PSSMA‐STO interaction contributed to a better distribution of nanoparticles. Fourier transformed infrared spectroscopy revealed that PSSMA and STO did not interfere in the polymerization of methyl methacrylate. This was further supported by thermal analysis, which also showed that the addition of PSSMA and STO had no significant influence on thermal degradation. On the other side, PSSMA and STO significantly enhanced mechanical performance of PMMA. The modulus of elasticity increased by up to 48.6%, total absorbed impact energy improved by up to 108.4%, and microhardness increased by up to 272.8% when PSSMA was combined with STO for reinforcing denture PMMA. These results demonstrate the significant potential of PSSMA, which could be combined with other ceramic nanoparticles for denture reinforcement in the future. Highlights: This research presents novel dental hybrid composite.Influence of strontium titanate (STO) and poly(4‐styrenesulfonic acid‐co‐maleic anhydride) sodium salt (PSSMA) on poly(methyl methacrylate) (PMMA) was investigated.PSSMA/STO improved modulus of elasticity, microhardness and impact resistance.Sample with 5 wt% PSSMA and 1 wt% STO showed the highest improvement compared to PMMA.Presented hybrid composite could use as denture base material. [ABSTRACT FROM AUTHOR]

The remarkable stability, suitable thermomechanical characteristics, and acceptable electrical properties of donor-doped strontium titanates make them attractive materials for fuel electrodes, interconnects, and supports of solid oxide fuel and electrolysis cells (SOFC/SOEC). The present study addresses the impact of processing and thermochemical treatment conditions on the electrical conductivity of SrTiO3-derived ceramics with moderate acceptor-type substitution in a strontium sublattice. A-site-deficient Sr0.85La0.10TiO3−δ and cation-stoichiometric Sr0.85Pr0.15TiO3+δ ceramics with varying microstructures and levels of reduction have been prepared and characterized by XRD, SEM, TGA, and electrical conductivity measurements under reducing conditions. The analysis of the collected data suggested that the reduction process of dense donor-doped SrTiO3 ceramics is limited by sluggish oxygen diffusion in the crystal lattice even at temperatures as high as 1300 °C. A higher degree of reduction and higher electrical conductivity can be obtained for porous structures under similar thermochemical treatment conditions. Metallic-like conductivity in dense reduced Sr0.85La0.10TiO3−δ corresponds to the state quenched from the processing temperature and is proportional to the concentration of Ti3+ in the lattice. Due to poor oxygen diffusivity in the bulk, dense Sr0.85La0.10TiO3−δ ceramics remain redox inactive and maintain a high level of conductivity under reducing conditions at temperatures below 1000 °C. While the behavior and properties of dense reduced Sr0.85Pr0.15TiO3+δ ceramics with a large grain size (10–40 µm) were found to be similar, decreasing grain size down to 1–3 µm results in an increasing role of resistive grain boundaries which, regardless of the degree of reduction, determine the semiconducting behavior and lower total electrical conductivity of fine-grained Sr0.85Pr0.15TiO3+δ ceramics. Oxidized porous Sr0.85Pr0.15TiO3+δ ceramics exhibit faster kinetics of reduction compared to the Sr0.85La0.10TiO3−δ counterpart at temperatures below 1000 °C, whereas equilibration kinetics of porous Sr0.85La0.10TiO3−δ structures can be facilitated by reductive pre-treatments at elevated temperatures. [ABSTRACT FROM AUTHOR]

Oxygen transport membranes (OTMs) can be operated as efficient oxygen separators and oxygen distributors, but their diffusion is hampered by the lack of appropriate materials with sufficient chemical stability in operating conditions. Mixed ionic‐electronic conducting SrTiO3‐based perovskite are a promising option due to their remarkable resistance in reducing environments, but they are prone to degradation in CO2‐containing atmospheres owing to carbonate formation. In this study, we propose new Ca1‐xSrxTi0.8Fe0.2O3‐δ perovskites where the Sr2+ cation is partially substituted by Ca2+ to improve the tolerance to CO2. We show that, upon increasing Ca molar fraction, the phase stability in CO2 is progressively improved thanks to the mitigation of carbonate growth. The manufacturing process of the membranes benefits from Ca introduction, which promotes powder densification during sintering. A membrane made of Ca0.1Sr0.9Ti0.8Fe0.2O3‐δ exhibited a stable oxygen flux for 340 h at 900°C when swept with He and for 170 h at 900°C when swept with a gaseous stream containing 40% CO2. Post‐test characterizations confirmed the retention of the crystal structure after the long‐term permeation tests. Ca‐substituted SrTi1‐yFeyO3‐δ perovskites can be considered promising materials for OTMs working in harsh environments and in the presence of CO2. [ABSTRACT FROM AUTHOR]

As smart materials, electrorheological elastomers (EREs) formed by pre-treating active electrorheological particles are attracting more and more attention. In this work, four Mg-doped strontium titanate (Mg-STO) particles with spherical, dendritic, flake-like, and pinecone-like morphologies were obtained via hydrothermal and low-temperature co-precipitation. XRD, SEM, Raman, and FT-IR were used to characterize these products. The results showed that Mg-STOs are about 1.5–2.0 μm in size, and their phase structures are dominated by cubic crystals. These Mg-STOs were dispersed in a hydrogel composite elastic medium. Then, Mg-STO/glycerol/gelatin electrorheological composite hydrophilic elastomers were obtained with or without an electric field. The electric field response properties of Mg-doped strontium titanate composite elastomers were investigated. We concluded that dendritic Mg-STO composite elastomers are high-performance EREs, and the maximum value of their energy storage was 8.70 MPa. The significant electrorheological performance of these products is helpful for their applications in vibration control, force transducers, smart structures, dampers, and other fields. [ABSTRACT FROM AUTHOR]

Barium - Strontium Titanate (BST), a ternary ceramic with high dielectric tunability has been the centre of attraction due to its proficiency in dynamic random-access memory (DRAM), tunable microwave application, etc. Ba0.6Sr0.4NixTi1-xO3 where x = 0.00, 0.02 and 0.04 were studied for its structural, optical and magnetodielectric properties. The samples were synthesized by standard solid state reaction method. Structural characterizations of BST performed using X-ray diffraction (XRD) showcase that it has simple cubic perovskite symmetry. Optical properties were studied using diffused reflectance spectroscopy. The optical band gap of x = 0.00, 0.02 and 0.04 samples were found to be 2.86 eV, 3.05 eV and 2.98 eV, respectively. Dilute doping of Ni in pristine BST changes the magnetodielectric (MD) behaviour of the sample considerably. The MD response, investigated under a perpendicular uniform magnetic fields of 0.58 T showed noticeable variations in the MD values and are attributed to the magnetostriction effect and the interfacial Maxwell-Wagner polarization. The electrical conduction in Ni doped BST sample has been modelled by the grain boundary resistance and hopping mechanism. The results open up a potential magnetocapacitance device application. [ABSTRACT FROM AUTHOR]

Developing low-cost and high-efficiency non-precious metal cocatalysts is the key to the practical application of photocatalysis technology. Here, nickel sulfide (NiS) nanoparticles were synthesized on the surface of strontium titanate (SrTiO 3) via a hydrothermal method, identifying the optimal loading molar concentration of NiS as 10 %. The solar-to-hydrogen efficiency (STH) of 10%NiS/SrTiO 3 :Al was enhanced by 97 times compared to SrTiO 3 :Al and by 1.62 times compared to RhCrCoO x /SrTiO 3 :Al. This improvement is primarily attributed to the metallic-like properties of NiS, which enhance the photocatalyst's light absorption capacity and charge transfer capability. Additionally, the STH value of samples loaded with both NiS and RhCrCoO x reached 0.436 %, indicating a positive synergistic effect in photocatalysis between NiS and RhCrCoO x. Their photocathodic protection capability was also studied in simulated seawater conditions, showing a reduced self-corrosion potential (−0.31V) and a low interface charge impedance (5962 KΩ). This work reveals the potential of NiS as an alternative to precious metal cocatalysts, offering new possibilities for developing cost-effective and high-performance materials for photocatalytic water splitting and photocathodic protection. [ABSTRACT FROM AUTHOR]

Capacitors and gate dielectrics are just two examples of when strontium titanate's dielectric properties would be helpful. The electrical and structural characteristics of Cr-doped B-site SrTiO3 have been investigated using First-Principle simulation. CrTi is a shallow acceptor because of the difference in valence between Ti and Cr; the results reveal that substituting a Ti ion Cr ion causes an internal strain originating from the offset between Ti-O and Cr-O bonding lengths. However, oxygen vacancy formation is significantly promoted in oxygen-poor environments. With a binding energy of 0.52±0.09 eV and no states in the gap, we discover that Vo may be attached to CrTi. We discussed how CrTi could help counteract or capture oxygen vacancy effects. [ABSTRACT FROM AUTHOR]

With strong electron–phonon coupling, self‐trapped excitons (STEs) are typically formed in perovskite materials, and radiative recombination of STEs can produce broadband emission with large Stokes shifts. STEs are essential to further improve the optoelectronic properties of materials. Surprisingly, 2D system is the edge case, with low even no self‐trapping barriers, leading to effortless formation of STEs. In this work, 2D strontium titanate (SrTiO3) with defects is prepared using supercritical carbon dioxide (SC CO2) and its carrier transport and transition are studied. The appearance of wide photoinduced positive absorption signals in the femtosecond transient absorption spectra is direct evidence for the formation of STEs. The presence of STEs is further supported by the increased Stokes shift and full width at half maximum in the steady‐state photoluminescence spectra. [ABSTRACT FROM AUTHOR]

Passive radiative cooling technologies play an integral role in advancing sustainable development. While the potential of polymer‐based radiative cooling materials is increasingly recognized, they often degrade under prolonged ultraviolet (UV) radiation exposure, which undermines both their mechanical and radiative cooling performance. To address this challenge, a coaxial electrospinning method to prepare a BST@TPU membrane, with a core layer of strontium barium titanate nanorods (BST NRs) and a shell layer of thermoplastic polyurethane (TPU) is employed. Capitalizing on the UV absorption and free radical adsorption properties of BST NRs, the UV stability of the TPU membrane is significantly increased. Additionally, the inclusion of high refractive index BST NRs compensates for the decrease in reflectivity caused by their UV absorption. After 216 h of continuous 0.7 kW m−2 UV irradiation, the BST@TPU membrane, which initially exhibits a reflectance of 97.2%, demonstrated a modest decline to 92.1%. Its net radiative cooling power maintains 85.78 W m−2 from the initial of 125.21 W m−2, extending the useful lifetime of the TPU membrane threefold. This innovation extends promise for enhancing the efficiency and durability of radiative cooling materials, contributing to sustainable cooling solutions across various applications. [ABSTRACT FROM AUTHOR]

In this study, we have successfully developed a novel surface exsolving perovskite ceramic, which demonstrates the ability to simultaneously generate CO x -free hydrogen and carbon nanotubes (CNTs) through methane pyrolysis under the influence of microwave irradiation. We conducted an extensive survey and optimization of various perovskite materials specifically tailored for microwave applications. Among the materials investigated, nickel-doped strontium titanium oxide (STON) emerged as the most promising candidate, exhibiting both a satisfactory methane conversion rate and excellent responsiveness to microwave irradiation. Refinement of STON was carried out by fine-tuning the Ni content, optimizing the reduction dwell time, and adjusting the reduction temperature. Notably, SrTiNi 0.08 O 3 (STON8), demonstrated an impressive initial methane conversion rate of up to 40%. Transmission Electron Microscopy (TEM) provided visual evidence of the correlation between Ni content and reduction temperature, with respect to the exsolved Ni metal particle size. This finding highlights the immense potential of surface exsolving perovskite ceramics as a highly effective catalyst for the simultaneous production of CNTs and COx-free hydrogen via methane pyrolysis under microwave irradiation. It represents a step forward in the field of catalytic materials and microwave-driven processes. • Ceramic materials are used for microwave methane pyrolysis. • Ni-doped strontium titanium oxides (STNO) show promising conversion rate. • Tuning Ni content and temperature controls Ni nanoparticle size and conversion efficiency. [ABSTRACT FROM AUTHOR]

Lead contamination in water poses significant health risks, making its removal imperative. In this study, magnetic strontium ferrite (SrFe12O19) nanoparticles were facilely synthesized by the Pechini sol–gel method and subsequently functionalized with a novel chitosan–Schiff base ligand to obtain a novel inorganic/organic nanocomposite for removing Pb(II) ions from aqueous solutions. The chitosan–Schiff base ligand was synthesized through the reaction of chitosan with 2,4,5-trihydroxybenzaldehyde. The presence of two X-ray diffraction (XRD) peaks at 2Ɵ = 10.5° and 2Ɵ = 20.5°, alongside the characteristic SrFe12O19 peaks, confirmed the functionalization of the nanoparticles with the ligand. Additionally, a significant decrease in the saturation magnetization value from 40.29 emu/g in pure SrFe12O19 nanoparticles to 17.32 emu/g in the nanocomposite further verified the functionalization. The presence of carbon (C) and nitrogen (N) atoms in the energy-dispersive X-ray (EDX) pattern of the nanocomposite, in addition to iron (Fe), strontium (Sr), and oxygen (O), also confirmed the functionalization. The nanocomposite's maximum adsorption capacity for Pb(II) ions was 390.63 mg/g. Moreover, the adsorption process is endothermic, spontaneous, and chemical, occurring via complexation with -C=N and -OH groups, and it fits well with the Langmuir equilibrium isotherm and the pseudo-second-order kinetic equation. [ABSTRACT FROM AUTHOR]

Mechanically activated strontium titanate (SrTiO3) powders with various manganese dioxide (MnO2) doping levels (1.5, 3 and 6 wt%) were prepared by solid state method. Due to the possibility of manganese ion incorporation in SrTiO3 at Ti4+ and/or Sr2+ sites a detailed analysis of the influence of dopants on the microstructure, morphology and optical properties of perovskite oxide was conducted. The investigation showed that manganese was incorporated into the lattice and surface layers of SrTiO3 particles with the presence of manganese segregation and inhomogeneities. Optical measurements indicated a shift of the absorption edge to higher values of wavelengths where the lowest value of the band gap (3.10 eV) was for the longest activation time (120 min) and the highest weight percentage of dopant (6 wt%). In the case of lower concentration (1.5 wt%), there was a significant relative contribution of the substitution of Sr2+ ions by Mn2+ ions, while the substitution of Ti4+ ions by Mn4+ ions dominated samples with an increased concentration. [ABSTRACT FROM AUTHOR]

Ruddlesden–Popper manganites are strongly correlated, quasi two-dimensional systems with highly tunable functional properties, which can, for example, be controlled by composition, strain, and defects. Praseodymium calcium manganite is a particularly interesting Ruddlesden–Popper system due to its remarkably high temperature at which ordering phenomena set in, enabling correlation physics above room temperature. However, in order to utilize the correlation phenomena and the quasi-two-dimensionality of the Ruddlesden–Popper systems for applications, one needs to grow thin film junctions, making it necessary to control the structure–property relation of Ruddlesden–Popper thin films. Here, we present a cryogenic transmission electron microscopy study of praseodymium calcium manganite thin films, deposited on niobium doped strontium titanate substrates, where we analyze the structure of the manganite thin film, as well as the effect of the epitaxial strain and defects on the charge/orbital order of the system. We identify a structural phase transition above the onset of charge/orbital order, frequently occurring extended defects and the temperature dependence and spatial distribution of charge/orbital ordering in the film. Our results show in detail the relationships between strain/defects and properties of the ordered phases and thus give important insights into how to tailor the functional properties of thin film junctions of strongly correlated materials. [ABSTRACT FROM AUTHOR]

The Solvothermal method was employed to produce bare TiO² nanoparticles and 5wt% SrTiO³. The resultant samples were investigated using various instruments including X-ray diffraction (XRD), UV- Visible spectroscopy (UV), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and high-resolution transmission electron microscopy (HRTEM). The growth and crystallization of SrTiO³ were analyzed using XRD. The SEM investigation revealed the spherical shape and aggregation of the nanoparticles, and the sample optical bandgap energy was found to be 3.2 eV. The maximal photodegradation efficiency of Congo red dye was achieved by the action of the valence band holes. [ABSTRACT FROM AUTHOR]

Surface modification, including the anchoring of functional groups is a popular method to increase the photocatalytic activity of semiconductor photocatalysts. These species can trap excited electrons, thus prolonging the life of the charge carriers. N-containing functional groups are suitable for this purpose due to their high electron density. Here, we report a facile synthesis method for preparing interfacial N-based functional groups-modified and nitrogen-doped SrTiO3 photocatalysts. Among the modified samples (with 0.42–11.14 at.% nominal nitrogen content), the one with 7.71 at.% nitrogen showed 6.4 times higher photooxidation efficiency for phenol and 2.2 times better photoreduction efficiency for CO2 conversion than the unmodified SrTiO3 reference. Characterization results showed that using a low amount of nitrogen source resulted in low but measurable nitrogen doping, which did not significantly affect the photocatalytic activity. The formation of surface amine groups was significant even at lower initial nitrogen concentrations, while higher amounts of nitrogen source gradually resulted in the incorporation of nitrogen in higher amounts. Surface amine groups decreased the recombination of charge carriers, resulting in increased photocatalytic activity.

Rescuing dental implants from plaque‐induced infection and implementing effective plaque control methods in a limited oral environment pose challenges for modern dentistry. To address this issue, Al ion doped strontium titanate/titanium dioxide nanotubes (Al‐SrTiO3/TiO2 nanotubes, Al‐STNT) are designed as an ultrasound‐responsive nanocoating immobilized on the Ti implant surface. Introducing Al3+ ions into the inorganic sonosensitive SrTiO3/TiO2 heterojunction induces oxygen vacancies and disrupts the lattice of SrTiO3. By overcoming the bandgap barrier through ultrasonic stimulated piezoelectric effect, Al‐STNT produces more reactive oxygen species (ROS). In the sonodynamic therapy (SDT) process, stimulus on Al‐STNT induces abundant ROS efficiently disrupting the bacteria biofilm and inhibiting biofilm metabolism. Moreover, the specific nanoscale SrTiO3 coating endows dental implants with osteogenic activity, facilitating the formation of rigid osseointegration between the implant surface and alveolar bone. By mimicking human dental implants in rats, Al‐STNT demonstrates optimal postimplant osseointegration while retaining its antibacterial ability as a sonosensitizer. Thanks to the portability of the ultrasound instrument and the stability of implant‐based sonosensitizer, this strategy presents an attractive option for patients to self‐treat and secure the long‐term success of their implants. [ABSTRACT FROM AUTHOR]

In this work, the ceramics of Sr(Ta 1/2 Al 1/2) x Ti 1-x O 3 (x = 0 %, 0.5 %, 1 %, 2 %, 3 %, 4 %, and 5 %) were produced through the solid-state reaction and sintered under N 2 atmosphere. The frequency coefficient of permittivity and dielectric loss for the sample with x = 4 % is blow |24%| and |26%|, respectively, within the frequency of 1 kHz to 1 MHz. This demonstrates favorable frequency stability in the dielectric properties. The sample with x = 4 % exhibits remarkable permittivity (ε r ∼ 125,000 @ 1 kHz, ε r ∼ 95,000 @ 1 MHz) and low dielectric loss (tanδ ∼ 0.054 @ 1 kHz, tanδ ∼ 0.044 @ 1 MHz) were achieved at room temperature. Through the analysis of HAADF-STEM, XPS, it is concluded that and dielectric relaxation, the colossal permittivity effect is primarily attributed to defect clusters associated with oxygen vacancies such as Ti3+ − V O • • − Ti3+. The clusters of defect dipoles exert a pinning effect on freedom electrons, constraining their long-range transition and improving the dielectric properties. This study lays the foundation for advancing the electronic components, making a significant milestone in technological advancements. [ABSTRACT FROM AUTHOR]

In recent years, electronic devices with trendy flexibility and compatibility have become the competitive alternative to conventional electronics. In the present work, flexible polymer nanocomposite films composed of poly(vinylidene fluoride-co-hexafluoropropylene), iron oxide, and strontium titanate (PVDF-HFP/SrTiO3/Fe2O3) were synthesized by the solution-casting method. The formation and structural features of this composite material have been analyzed by X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric (TGA), and SEM. SEM results confirm the homogeneous dispersion of SrTiO3 and Fe2O3 within the host polymer. The uniform dispersion of the embedded metal species enhances the dielectric values up to 462 on optimization with infused rigidity. The impedance studies of PVDF-HFP/SrTiO3/Fe2O3 were performed in the temperature region of 50–150 °C at various frequencies ranging from 50 Hz to 10 MHz and the AC conductivity studies suggested that synthesized polymer nanocomposite shows higher conductivity with the maximum conductivity value was 8.20 × 10−3S/m. Polymer nanocomposite films with large dielectric constant and minimum dielectric loss are highly recommendable for flexible energy storage applications. Also, rapid development of novel material for flexible electronics is in great demand, which suggests it is an alternate source for future energy storage application. [ABSTRACT FROM AUTHOR]

Slater's formula for perovskite ferroelectrics was modified by Barrett to include the quantum effect. Dielectric constant vs temperature (ε' vs. T) data for Strontium titanate (ST) and Potassium tantalate (KT) in single crystals and ceramics fitted well, while the data (ε' vs. T) for Barium titanate (BT) in single crystals and ceramics did not fit at all to Barrett's equation. That is, ferroelectrics like ST, which show only Curie-Weiss temperature but does not show a ferroelectric transition, obey Barrett's equation. The Curie-Weiss law fitted the data of BT well. That KT a cubic and consequently a paraelectric down to 13 K obeys Barrett's equation is intriguing. ε' vs T values of Barium strontium titanate (BaxSr1-xTiO3), thin films could be fitted to the Curie-Weiss law, thus eliminating the existence of quantum effect in thin films. [ABSTRACT FROM AUTHOR]

Free-standing flexible poly(vinylidene fluoride)-barium strontium titanate (PVDF-BST) composite films loaded with 5 vol% of Ba0.7Sr0.3TiO3 submicronic particles have been synthesized. The synthesized PVDF-BST composite film was quenched in ice water as quenching strongly affects its crystalline phase, dielectric and energy storage behavior. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) studies confirmed that quenching leads to the evolution of the β-phase of PVDF in the PVDF-BST composite films. At 1 kHz, the dielectric constant of the quenched film is ~ 17, which is higher than that of the unquenched film, i.e. ~ 15. At 460 kV/cm, the energy density of the quenched film is 2.5 times higher (~ 4.8 J/cc) as compared to the unquenched film (1.9 J/cc). Significant improvement in the dielectric constant and energy density is attributed to the formation of β-phase of PVDF in PVDF-BST composite film. Mechanism for β-phase formation by quenching at low temperatures has also been suggested. [ABSTRACT FROM AUTHOR]

This study estimated the amount of oxygen deficiency in SrTiO 3 polycrystals that were flash sintered under direct current (DC) and alternating current (AC) electric fields, mainly by using the fine structural change of the Ti L 23 -edges collected by electron energy-loss spectroscopy. The DC electric field corresponded to formation of the maximum amount of oxygen deficiency at approximately δ = 0.07 as SrTiO 3−δ , which corresponds to a lattice expansion of roughly 0.1% as a lattice constant of SrTiO 3. Furthermore, the oxygen deficiency was distributed unevenly. The formation of dislocation networks in DC-flash-sintered SrTiO 3 polycrystals might be related to the lattice strain field caused by this nonuniform oxygen deficiency. In contrast, an AC electric field did not correspond to the oxygen deficiency of SrTiO 3 , which is similar to the results in thermally sintered SrTiO 3 polycrystals. [ABSTRACT FROM AUTHOR]

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The structural and electrical properties were studied in ferroelectric composites based on barium and strontium titanates with the addition of boric anhydride, which were synthesized by low-temperature sintering. The obtained materials are promising for creating electrically controlled metamaterials with bulk ferroelectric inhomogeneities. [ABSTRACT FROM AUTHOR]