Enhancing the piezoelectric response of the perovskite-layered structure (PLS) ceramic Sr2Nb2O7 is essential for high-temperature piezoelectric sensing. Here, V/Mn co-doping was employed to improve the performance of Sr2Nb2O7 (SNVMx) ceramics. Structural refinement combined with Shimakawa-model calculations indicates an increased spontaneous polarization upon V/Mn incorporation, associated with an enlarged separation between the centers of positive and negative charges. High-resolution TEM and SAED reveal the features of both the superlattice and local defect-related microstructural heterogeneity, suggesting dopant-induced structural modulation and local strain fields that may contribute to an enhanced intrinsic electromechanical response. Piezoresponse force microscopy further shows enlarged domain features, increased piezoresponse amplitude, and reduced local coercive voltage (VC) in the doped ceramics, implying facilitated switching and improved domain-wall mobility, i.e., a strengthened extrinsic contribution. Consequently, the piezoelectric coefficient reaches d33 approximate to 3.5 pC N-1 while maintaining a TC above 1200 degrees C. Moreover, depolarization tests confirm stable piezoelectric performance after annealing up to 800 degrees C, supporting the potential of V/Mn co-doped Sr2Nb2O7 for high-temperature applications.

V/Mn co-doping enhances the intrinsic and extrinsic piezoelectric responses of Sr 2 Nb 2 O 7 ceramics through increased B-site octahedral distortion, spontaneous polarization, and domain-wall activity, giving d 33 = 3.5 pC N −1 .

Differentiating photoelectric response in a single material with a simple approach is desirable for all-in-one optoelectronic logical devices. In ferroelectric materials, significantly distinct photoelectric features should be observed if they are in diverse polarization states, unveiling a possible pathway to realize multifunctional optoelectronic logic gates through ferroelectric polarization design. In this study, the Ti3+ self-doping strategy is first applied to 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 ferroelectric ceramics (BZT-BCT-xT) through co-firing metallic Ti powders and BZT-BCT powders to enhance photoelectric output. Subsequently, on the BZT-BCT-3T ceramic surface that has optimal photoelectric properties, three individual regions are separated and heterogeneously polarized by using a novel planar three-electrodes structure. Intriguing illumination region-dependent photocurrent directions are demonstrated in this as-fabricated device. Based on this, five basic optoelectronic logic gates are integrated into single ferroelectric ceramic via fully light-controlled methods, including "AND", "OR", "NOT", "NAND" and "NOR". These gates can be readily switched by simply altering the output electrodes or light intensity of 405 nm LED modulating light. This work not only puts forward an innovative strategy for designing ferroelectric optoelectronic logic gates, but also provides feasibility for more ferroelectric materials to be applied in logical devices.

Anomalous photovoltaic effect of ferroelectrics is receiving intensive research interests. However, many ferroelectric materials struggle to effectively harness the solar spectrum due to their large bandgaps. AgNbO3 has partial visible-light response, but weak photoelectric/photovoltaic performance. Here, we prepare and report the photoelectric/photovoltaic performance of Ag1-xKxNbO3 solid-solution ceramics. The results indicate that all the investigated ceramics exhibit a narrow bandgap (Eg approximate to 1.95 eV); mechanical polishing further improves lightabsorption, enhancing photoelectric response. Composition-driven improvements in photoelectric/photovoltaic performance were observed, which is closely linked to the enhanced ferroelectricity. The poling electric-field effect on photoelectric/photovoltaic performance and ferroelectric properties reveals that the open-circuit voltage (Voc) and short-circuit current (Jsc) are directly proportional to the remnant polarization until the applied field reaches 100 kV/cm. Upon illuminating the polarization-saturated ferroelectric ceramic (x = 0.07) surface, the maximum Voc (=8 V) and Jsc (=1 mu A/cm2) were achieved, which are 10 times and 35 times larger, respectively, than those of AgNbO3 ceramics.

Sr2Nb2O7 (SNO) ceramics are promising high-temperature piezoelectric materials due to their high Curie temperature (T-C), good thermal stability, and high electrical resistivity. However, SNO presents low piezoelectric activity (d(33) < 1 pC/N). Here, we successfully obtain textured SNO ceramics with an orientation factor of 0.86 by microstructure regulation. Saturated polarization-electric loop was obtained in textured ceramic with remanent polarization P-r similar to 3.56 C/cm(2) and coercive field E-C similar to 53.4 kV/cm. The piezoelectric coefficient d(33) of the textured SNO ceramics is increased to 3.2 pC/N, with a high T-C of 1342 degrees C, while the low-textured SNO ceramics exhibit no effective d(33). Meanwhile, the piezoelectric coefficient d(33) of textured SNO ceramics maintains consistency even at 1300 degrees C, showing excellent thermal stability. The underlying mechanism driving this improvement is elucidated, emphasizing the facilitated domain-wall motion enabled by the engineered microstructure. Furthermore, textured SNO ceramics exhibit high resistivity of 1.33 x 10(6) Omega & sdot;cm at 800 degrees C. This study presents a simple and feasible microstructure engineering approach to enhance the piezoelectric properties of layer-structured materials, offering valuable insights into the design and development of ceramics for diverse applications.

By converting light into mechanical strain, photostrictive materials are expected to define a revolutionary solution to the wireless micro-electromechanical devices. However, the photoinduced strain (photostriction) of most inorganic materials are unsatisfactory as compared to the electric-field-induced strain of ferro/piezoelectric materials. Here, we demonstrate the effective optimization of the photostriction of inorganic materials by constructing polymorphic phase boundary (PPB) in Pb3V2-xPxO8 compounds. Large photostriction over 0.3% and excellent photostrictive efficiency in the level of 10-10 m3/W are realized in Pb3V2-xPxO8 compositions at the PPB region, which perform better than most of the existing inorganic photostrictive materials. Besides, photostriction over 0.1% (same level of piezoelectric strain) can be achieved with light intensity as low as 200 mW/cm2. We theoretically reveal that enhanced photostriction arises from photoinduced phase transition driven by Pb-O-V collinearity and V-V dimer formation, and P-doping can facilitate the transition, enabling large deformation at low photoexcitation. This work will accelerate the development of high-performance inorganic photostrictive materials and their applications for optomechanical devices. Photostrictive materials offer a promising solution for the realization of wireless microelectromechanical devices. Here the authors demonstrate a method for developing high-performance inorganic photostrictive materials by constructing a polymorphic phase boundary.

Organic/inorganic thermoelectric (TE) composite fibers are promising for wearable electronics due to their flexibility and energy conversion capabilities, yet their performance remains limited. Here, we have successfully developed novel dual‐interfacial structured poly(3,4‐ethylene dioxythiophene):poly(styrene sulfonate)/single‐walled carbon nanotube@ polyaniline (PEDOT:PSS/SWCNT@PANI) TE composite fibers via wet‐spinning PANI was introduced between SWCNTs and PEDOT:PSS as an interlayer, which not only improved the dispersibility of SWCNTs in aqueous PEDOT:PSS but also facilitated the formation of numerous highly uniform dual‐interfaces at PEDOT:PSS/PANI and PANI/SWCNT contacts.Therefore, the PEDOT:PSS/SWCNT@PANI composite fibers exhibited a high degree of structural alignment and more efficient energy filtering effect. Furthermore, introducing PANI interlayers between SWCNTs and PEDOT:PSS also provided a facile route for finely tuning the carrier concentration of the ternary composite system. With an ammonium hydroxide treatment performed on PANI before fiber spinning, the TE properties of the ternary composite fibers are further optimized. The PEDOT:PSS/SWCNT@PANI composite fibers eventually delivered electrical conductivity of 2472 ± 23.3 S cm −1 and a Seebeck coefficient of 43.5 ± 0.7 µV K −1 . The corresponding power factor reached 467.8 ± 10.5 µW m −1 K −2 , which is remarkably higher than that of other PEDOT:PSS‐based composite fibers. This work domonstrates interfacial engineering as a critical strategy for high‐performance TE fibers, advancing their potential in flexible electronics.

Calcium borosilicate (CBS) low temperature co-fired glass-ceramic substrates exhibit excellent dielectric properties in microwave wireless devices. Since the multiphase competition that occurs during the sintering of CBS glass-ceramics, achieving a high ratio of β-CaSiO3 crystalline phases with dielectric properties is of critical importance. Here, by introducing varying levels of β-CaSiO3 crystals as seed crystals, a highly crystalline β-CaSiO3 phase was formed while achieving a dense glass-ceramic, and the crystal growth regulations were explored. Specifically, with a doping level of 3 wt% β-CaSiO3, the glass-ceramics achieve optimal densification and a crystalline phase comprising 75 % β-CaSiO3, with a low dielectric constant (5.03 at 1 MHz) and low dielectric loss (5.09 × 10⁻⁴ at 1 MHz). The flexural strength exhibits 196.4 MPa. Moreover, the different crystallization stages, corresponding to various morphology crystal sizes, were identified. Our work presents a method for introducing seed crystals to induce spherical crystal growth in low-dielectric glass-ceramics.

Bismuth oxychloride (BiOCl) square microplates were prepared via a facile hydrothermal method. The X-ray diffraction patterns of the samples reveal a tetragonal BiOCl phase, and the scanning electron microscopy images show plate-like structures with large lateral size of 3 similar to 6 mu m and thickness in the range of 100 similar to 300 nm. The effects of surfactant, reaction temperature and duration on the morphology of BiOCl powders are systematically investigated. The polar behavior of a BiOCl single-crystalline microplate is examined by using piezoresponse force microscopy evidenced over 80 pm displacement under 40 V bias voltage. In addition, the photoelectric performance of the BiOCl microplates is evaluated by using electrochemical workstation with three-electrode system, and large photocurrent densities (over 0.5 mu A/cm(2)) and fast photoresponse (0.7 similar to 1.1 s) are detected by applying both 365 nm monochromatic light and sunlight illumination. The surface potential changes of BiOCl microplate under different light condition, characterized by in-situ Kelvin probe force microscopy, further verify the separation ability of the photo-induced charge carriers. These fmdings would be beneficial for further design photocatalytic and piezocatalytic materials.

The instability of the perovskite precursor solution seriously affects the purity of the perovskite films, which is one of the key factors for the low reproducibility for highly efficient devices. Formamidinium-based perovskite with more suitable spectral absorption range and higher thermal stability has become the mainstream material. However, the side reactions in pure formamidinium lead iodide solution have not been fully revealed. Herein, it is demonstrated that self-condensation of formamidinium iodide occurs to form the by-product s- triazine, and its content increases with the aging time of the solution. It is also discovered that phenylboric acid (PBA) can effectively inhibit the self-condensation reaction and the content of the s- triazine is decreased by more than 95% in the solution aging at 60 degrees C for 7 days. The PBA used as the stabilizer not only enhances purity and decreases defect density of the perovskite films but also strongly enhances the reproducibility for highly efficient perovskite solar cells.

In article number 2010706, Zhiguo Yi and Chen Chen review the recent progress in the photostrictive effect, with a focus on the characterization techniques, the exploration of new photostrictive materials, and their potential applications. The challenges and prospects for the future development of the photostrictive effect is presented. This article could not only encourage research on the underlying mechanisms, but also accelerate the exploration of high-performance photostrictive materials.

We report on high dielectric constant (8.3 × 103, 104 Hz), low dielectric loss (0.029, 104 Hz) as well as fine grain size (∼840 nm) achieved in pure CaCu3Ti4O12 (CCTO) ceramics through a combination of sol–gel method, spark plasma sintering and annealing process. By adjusting the sintering temperature and annealing conditions, the composition variations, valence states and microstructures of CCTO ceramics are systematically studied, which provide direct clues in understanding the origin of their excellent dielectric response. Through the studies on the dielectric, impedance, modulus and conductivity properties of CCTO ceramics, a modified brick-layer model based on two interfacial polarizations originating from sub-grain boundary and grain boundary barriers is proposed to explain their dielectric behaviors. The high dielectric constant of CCTO ceramics is mainly dominated by the sub-grain contribution; and the reduced dielectric loss is attributed to the decreases of electrical conductivity and relaxation loss.

Photostrictive effect that has been discovered for over half a century is getting renewed interest in recent years in view of the great potentials for optomechanical applications. Ferroelectric materials represented by lead lanthanum zirconated titanate have been widely studied in this field because of their relatively large photostriction and fast photoresponse, but their wide bandgaps with limit response to visible light hinder further practical application. Here, visible-light-driven photostrictions of the order of 10−3 are discovered in Bi(Ni2/3Nb1/3)O3–PbTiO3 (BNNPT) ferroelectric solid solutions. Three BNNPT compositions with different phase structures, exhibiting notably different piezoelectric and photovoltaic properties, are selected to conduct the photostriction investigation, and their analogous photostrictive behaviors contradict with previous acknowledgment that the photostriction of ferroelectrics originates from the photovoltage-induced inverse piezoresponse. The nonuniform shifts of the XRD diffraction peaks under external laser illumination and the redshifts of the laser power dependent Raman modes disclose that the photostriction is mainly attributed to the light-induced distortion of BO6 octahedra. This study sheds insight into the mechanism of the photostriction of ferroelectrics.

(1- x )CaTiO 3 - x Ni 0.5 Zn 0.5 Fe 2 O 4 (0 ≤ x ≤ 1.0) composite ceramics were synthesized by a conventional solid state reaction method. The phase formation, microstructure, and dielectric and magnetic properties were investigated by X-ray diffraction, scanning electron microscopy, precision impedance analysis, and vibrating sample magnetometry, respectively. The results indicate that the composite ceramics are composed of both perovskite phase CaTiO 3 and spinel phase Ni 0.5 Zn 0.5 Fe 2 O 4 . The maximal relative density for 0.5CaTiO 3 -0.5Ni 0.5 Zn 0.5 Fe 2 O 4 composite ceramics reaches 97.8%, as it has been sintered at the temperature of 1260 °C for 3 h. Dielectric constant and loss tangent of (1- x )CaTiO 3 - x Ni 0.5 Zn 0.5 Fe 2 O 4 composite ceramics show dispersion in the low frequency range. Their phase transition temperature of the dielectric constant shifts to lower temperatures with the increase of Ni 0.5 Zn 0.5 Fe 2 O 4 content. This phenomenon is attributed to that the phase transition temperature of CaTiO 3 is higher than that of Ni 0.5 Zn 0.5 Fe 2 O 4 . The saturation magnetization of (1- x )CaTiO 3 - x Ni 0.5 Zn 0.5 Fe 2 O 4 composite ceramics increases with the Ni 0.5 Zn 0.5 Fe 2 O 4 ferrite content.

本文通过对材质、技术以及资源状况等方面的综合分析,采用质轻、不燃的膨胀珍珠岩颗粒为保温材料,使用水玻璃粘结剂,再加入少量有机硅防水剂、乳化剂和分散剂等,进行搅拌、压制成型、热固化等工艺过程,制备出安全环保的耐高温墙体保温材料.对该制品进行性能测试分析,确定出粘合剂和防水剂的最优配方和最佳的制作条件.本研究开发的膨胀珍珠岩保温材料的干密度、质量含水率、抗压强度、整体憎水率、高温灼烧线性收缩率和导热系数的性能指标符合国家标准,其制作过程简单,原料成本低,且具有不燃、质轻和防水性好等突出特点,生产过程中无三废排放,具有很好的应用前景.

It is the rheology behavior of suspension that is the key of the gel-casting. Concentrated zirconia suspension and low viscosity are needed to prepare zirconia suspension. The effects of p H value,dispersant,solid loading,the mass fraction of AM and the ratio of MBAM to AM on the rheology behavior of suspension were discussed in detail. The results show,when p H value is about 10 and the mass fraction of dispersant is 0. 3wt%,the mass fraction of AM is 1. 0wt%,the ratio of MBAM to AM is 20∶1,the dispersive effect is the best and the viscosity is 2. 12 Pa·s.

采用固相反应法合成了（1-x）CaTiO3/xNi0.5Zn0.5Fe2O4（0≤x≤1.0）复合材料,并研究了复合材料的物相、微观结构、介电性能和磁性能。结果表明:样品中仅含有钙钛矿型CaTiO3和尖晶石型Ni0.5Zn0.5Fe2O4。1260℃保温3h,样品相对密度达到98.91%,颗粒尺寸约为2μm。样品介电常数随Ni0.5Zn0.5Fe2O4含量（x）增加而增大。当x=0.7、测试频率为103 Hz时,样品介电常数（εr）和介电损耗（tanδ）分别为2629.18和1.74。（1-x）CaTiO3/xNi0.5Zn0.5Fe2O4复合材料显示磁性。其中x=0.7时,样品饱和磁化强度（Ms）达到49.07A·m2/kg;这归因于Ni0.5Zn0.5Fe2O4具有优异的磁性能。

A simple and sensitive method for the detection of breast cancer DNA based on hairpin DNA,nanoparticles and screen-printed carbon electrode(SPCE)was described.AuNPs were modified with a dually labeled DNA probe(DLP)in a hairpin structure with biotin labeled at one end and sulfhydryl labeled at the other end.In the absence of target DNA,the DLP probe remained in the stem-loop structure.Upon contacting with the target DNA,the hairpin structure was destroyed and then the biotin was available for conjugation with the streptavidin modified magnetic nanoparticles.Then,the formed complex was magnetically separated from the solution and AuNPs were electrochemically detected on SPCE.The DNA sensing technology could detect as low as 8.0×10-13 mol/L complementary DNA and it also had the excellent differentiation ability for single-base mismatched sequences.