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Due to the excellent shear‐mode piezoelectric properties, single‐domain tetragonal Pb(In1/2Nb1/2)O3‐Pb(Mg1/3Nb2/3)O3‐PbTiO3 (PIN‐PMN‐PT) crystals are believed to possess giant electro‐optic (EO) coefficients as well. However, the EO properties of single‐domain PIN‐PMN‐PT crystals have not been systematically studied because of the difficulties in the single‐domain sample preparation. Here, by this newly developed orthogonal poling method, single‐domain tetragonal PIN‐PMN‐39PT crystals are successfully obtained by poling the sample along the non‐spontaneous polarization direction at room temperature. Optical grade crystal with good transparency and high EO coefficient component γ51 (≈2800 pm V−1) is achieved. The orientation dependence of the EO coefficient is analyzed based on the measured full matrix of the EO coefficients. This work confirms the giant EO performance of domain‐engineered PIN‐PMN‐PT single crystals mainly comes from the contribution of EO coefficient component γ51 of single domain crystal other than the domain wall or domain switching related mechanisms. [ABSTRACT FROM AUTHOR]

In this paper, we studied the formation of self-organized domain arrays created by moving biased tip of scanning probe microscope (SPM) in deuterated TGS crystals. The shape of created domains depends significantly on scanning direction and applied voltage. For scanning along c axis, the domain shape drastically changed from arrays to stripe domains at 150 V. Scanning perpendicular to c axis led to formation of the array of the dashed domains. Increasing of the dashed domain length leads to change of domain shape from arrays of dashed domains to solid stripe domain. The obtained effect has been considered in terms of the kinetic approach as a result of formation of comb-like domain with charged domain walls in the bulk due to repetitive appearance of the domain spikes. The spontaneous backswitching under the action of the depolarization field leads to the fast growth of the tooth to the surface and results in the transformation of the domain shape. The computer simulation of the nonuniform motion of charged domain wall under the action of depolarization field has been done. The obtained results demonstrate the essential role of screening processes and pave the way for further improvement of domain engineering methods. [ABSTRACT FROM AUTHOR]

The ferroelectric domain plays an important role in determining the piezoelectric performance of ferroelectric ceramics. Herein, LiNbO 3 (LN) is used as an additive to tune the ferroelectric domain of 0.49Pb(Ni 1/3 Nb 2/3)O 3 -0.2Pb(In 1/2 Nb 1/2)O 3 -0.31PbTiO 3 (PNN-PIN-PT) ceramics. PNN-PIN-PT-0LN ceramic exhibits the ordered tetragonal phase (90 °) domain wall and rhombohedral phase (71 ° and 109 °) domain wall. Incorporating LN into the system leads to the transformation of the majority of structured macro-domains into random micro-domains with smaller sizes, which disrupt their long-range ordered ferroelectric domains, resulting in significant piezoelectric enhancement. Compared to PNN-PIN-PT-0LN ceramics, PNN-PIN-PT-1.8LN ceramics exhibit giant piezoelectric responses with d 33 = 1112 pC/N, d 31 =521 pC/N, d 33 * =1220 pm/V (@ E = 5 kV/cm), ε r = 12092. These findings shed light on a specific aspect of domain engineering in piezoelectric materials, thus contributing to a more comprehensive understanding of the underlying factors that give rise to the phenomenon of giant piezoelectricity. [ABSTRACT FROM AUTHOR]

In this paper, we studied the formation of self-organized domain arrays created by moving biased tip of scanning probe microscope (SPM) in deuterated TGS crystals. The shape of created domains depends significantly on scanning direction and applied voltage. For scanning along c axis, the domain shape drastically changed from arrays to stripe domains at 150[Formula: see text]V. Scanning perpendicular to [Formula: see text] axis led to formation of the array of the dashed domains. Increasing of the dashed domain length leads to change of domain shape from arrays of dashed domains to solid stripe domain. The obtained effect has been considered in terms of the kinetic approach as a result of formation of comb-like domain with charged domain walls in the bulk due to repetitive appearance of the domain spikes. The spontaneous backswitching under the action of the depolarization field leads to the fast growth of the tooth to the surface and results in the transformation of the domain shape. The computer simulation of the nonuniform motion of charged domain wall under the action of depolarization field has been done. The obtained results demonstrate the essential role of screening processes and pave the way for further improvement of domain engineering methods.

In this work we have studied the stripe domain structure created by single pulse IR laser irradiation in CLT crystals covered by a conductive layer. The formation of three types of domain patterns was distinguished: (1) the central region with curved stripe domains, (2) the middle region with straight rays and branches oriented in three directions, and (3) the wide edge region covered by parallel straight rays oriented in only one direction. The obtained results have been considered as domain growth in highly-nonequilibrium switching conditions under the action of spatially nonuniform pyroelectric field arising during cooling after pulse laser irradiation. [ABSTRACT FROM AUTHOR]

In this work, we have studied the shape evolution of the isolated domains in domain array in congruent lithium niobate crystals under the action of pyroelectric fields arising during multiple irradiation by laser pulses. The loss of the circle shape with the pulse number was obtained in the arrays of isolated domains arising at the edges of the irradiated zone. The simulation of the domain growth under the action of the pyroelectric field allowed revealing two stages of domain shape evolution in the regular domain array. An important role of the neighboring domains was revealed. [ABSTRACT FROM AUTHOR]

The creation of periodic domain structures in lithium niobate crystals makes it possible to realize highly efficient nonlinear optical interactions in optical waveguides. The influence of near-surface H+ ion concentration gradient on the domain kinetics in uniform electric field in lithium niobate crystals modified by soft proton exchange is studied. The spatial distribution of the Hþ ions concentration in the surface layer is obtained by confocal Raman microscopy. The observed anomalous evolution of the domain structure at the surface represents the formation of stripe domains and their anisotropic growth along three directions. The domain imaging in the bulk allows revealing a comb-like domain shape. The obtained strong influence of the proton exchange duration on the threshold field is attributed to the action of the concentration gradient in the nearsurface layer, which is considered as an analog of the internal bias electric field. It is shown that the internal bias field is proportional to the increase in the concentration gradient in the surface layer. The mechanism of the comb-like domain formation is proposed. The obtained results can be used for development of domain engineering methods in optical waveguides. [ABSTRACT FROM AUTHOR]

The formation of the ferroelectric domain structure as a result of irradiation by focused ion beam of [100]-cut 0.61Pb(Mg 1 ∕ 3 Nb 2 ∕ 3) O3–0.39PbTiO3 (PMN–PT) single crystals covered by surface artificial dielectric layer and with free surface was investigated. The dot irradiation resulted in formation of the wedge-like domains grown along [00 1 ̄ ] direction. For irradiation of the free surface, the domains are mainly located under the surface, while at the irradiated surface with an artificial dielectric layer the domains are located at the surface. It was shown that the subsurface wedge-shaped part of the domain is unstable and completely disappears after a month due to spontaneous backswitching under the action of the residual depolarization field. The revealed nonlinear dose dependence of the domain sizes was attributed to the distribution of the electric field using the point charge model. The domain interaction for the distance between irradiated dots below 30 μ m has been revealed in all samples. It was shown that the decrease of the distance between irradiated dots in the created domain row leads to an increase in the length of the central domains, which is explained by the contribution of all injected charges to the switching field. [ABSTRACT FROM AUTHOR]

This study aims to suggest variability mechanisms for software product line development and to explain the results of case study. Software product line engineering is an extension of software engineering and many organizations constantly engage in reengineering and refactoring to adopt the software product line engineering. Software product line engineering has two engineering processes: domain engineering process and application engineering process. Feature Identification and feature model are key success factor to construct variability model. Feature model describes the variable parts to be extended or replaced and common part to be reuse by themselves. Feature model gives the directions to the following architecture design and component implementation. However, feature model is not the design strategy and variability mechanism for product line implementation. Therefore, these are the obstacles for organizations that are unfamiliar with feature model and variability mechanism to adopt software product line engineering. Several variability mechanisms for software intensive software are suggested but these are not applicable for embedded software since it has different development process and structure. In this paper, variability elements in architecture design and component design of embedded software are identified as state variable, state transition information, and algorithm. Variability management mechanisms are defined for these elements. To provide the detail strategy and to evaluate the suggested variability management methods, process and results of real case study are described.

Lead-based piezoelectric ceramics are the preferred material for commercial piezoelectric ceramic actuators due to their high performance and irreplaceability. However, the operating temperature (<100 °C) and strain (0.1 %∼0.2 %) of lead-based piezoelectric ceramics are still limited. Achieving large strain in a wide temperature range remains challenging. In this paper, a new strategy is proposed to effectively increase the strain value of lead-based piezoelectric ceramics through domain engineering. The new x PbTiO 3 -(0.97- x)PbZrO 3 -0.03(La 0.1 Sr 0.80.1)TiO 2.95 (x PT-PZ-LST) ternary piezoelectric ceramic system reaches a strain value as high as 0.5 % and exhibits extremely high temperature stability (13 %) in the range of 25–230 °C. By fine-tuning the content of PT components, the average length and width of a typical tetragonal domain are transformed from 800 nm to 80 nm (long and thin) to 300 nm and 200 nm (short and wide), relatively. From the experimental results of PFM and Rayleigh analysis, the high strain can be attributed to the synergistic effect of the reduced coercive field (E c), enhanced micro-region response, and regulated domain morphology, which ensures that high intrinsic and extrinsic contribution can be achieved at the same time. In this paper, a new strain regulation method is provided for lead-based piezoelectric ceramics, and a valuable large strain material is obtained via domain engineering. [ABSTRACT FROM AUTHOR]

The formation of the ferroelectric domain structure as a result of irradiation by focused ion beam of [100]-cut 0.61Pb(Mg[Formula: see text]Nb[Formula: see text]O3–0.39PbTiO3 (PMN–PT) single crystals covered by surface artificial dielectric layer and with free surface was investigated. The dot irradiation resulted in formation of the wedge-like domains grown along [00[Formula: see text]] direction. For irradiation of the free surface, the domains are mainly located under the surface, while at the irradiated surface with an artificial dielectric layer the domains are located at the surface. It was shown that the subsurface wedge-shaped part of the domain is unstable and completely disappears after a month due to spontaneous backswitching under the action of the residual depolarization field. The revealed nonlinear dose dependence of the domain sizes was attributed to the distribution of the electric field using the point charge model. The domain interaction for the distance between irradiated dots below 30[Formula: see text][Formula: see text]m has been revealed in all samples. It was shown that the decrease of the distance between irradiated dots in the created domain row leads to an increase in the length of the central domains, which is explained by the contribution of all injected charges to the switching field.

The current approach to 2D optical phased array (OPA) encounters challenges, such as the requirement for a highly tunable laser that is incompatible with certain 2D beam-steering applications or significant power consumption, large antenna spacing and complex wiring resulting from independent control of array elements. To address these challenges, we propose an OPA architecture based on cascaded periodically poled LiNbO3 sequences, a multi-layered domains engineered structure within the LiNbO3 electro-optic crystal, only two control electronics to program the 2D beam-steering trajectory with a range of approximately θ y = ±20° and θ z = ±16° through simulations. This structure enables the uniform distribution of phase differences between adjacent array elements (adjacent domains) upon beam exit from the crystal, ensuring optimal performance. The aim of this study is to develop a methodology that employs domain engineering techniques for designing high-performance phase-controlled devices with customized functional units and sequences in electro-optical crystals. Our research has implications for emerging optoelectronic applications, such as customizable optical interconnects and integrated LiDAR systems.

Lead-free BiFeO3-BaTiO3 ceramics attract widespread attention over the last two decades due to their high Curie temperature (TC) and excellent piezoelectric performance. Here, in the Nd-modified 0.67BiFeO3-0.33BaTiO3 ceramics, an excellent piezoelectric constant (d33) of 325 pC/N was achieved by applying a novel poling method (AC-bias + DC-bias) with a high TC of 455 °C. In addition, an ultrahigh normalized piezoelectric strain (d33∗ = Smax/Emax) of 808 pm/V was obtained at the normal/typical and relaxor-ferroelectrics phase boundary simultaneously with good thermal stability (Δd33∗(T) ≈ 20%) in the temperature range of 25–125 °C. The piezoelectric force microscopy results show the domain miniaturization from micro to nanoscale/polar nano-regions due to local structure heterogeneity caused by Nd doping. The mechanism for the giant piezoelectric strain is attributed to the thermal quenching, nano-domains, and reverse switching of the short-range order to the long-range order under the applied electric field. The strategic design of domain engineering and a proposed model for the high piezoelectricity is successfully supported by the phenomenological relation and Gibbs free energy profile. In this work, a new lead-free single-element modified BiFeO3-BaTiO3 ceramics was developed by applying a synergistic approach of domain engineering and phase boundary for the high-temperature piezoelectric performance.

Dielectric materials are highly desired for pulsed power capacitors due to their ultra-fast charge-discharge rate and excellent fatigue behavior. Nevertheless, the low energy storage density caused by the low breakdown strength has been the main challenge for practical applications. Herein, we report the electric energy storage properties of (1 − x) Bi0.5(Na0.8K0.2)0.5TiO3-xBi0.2Sr0.7TiO3 (BNKT-BST; x = 0.15–0.50) relaxor ferroelectric ceramics that are enhanced via a domain engineering method. A rhombohedral-tetragonal phase, the formation of highly dynamic PNRs, and a dense microstructure are confirmed from XRD, Raman vibrational spectra, and microscopic investigations. The relative dielectric permittivity (2664 at 1 kHz) and loss factor (0.058) were gradually improved with BST (x = 0.45). The incorporation of BST into BNKT can disturb the long-range ferroelectric order, lowering the dielectric maximum temperature Tm and inducing the formation of highly dynamic polar nano-regions. In addition, the Tm shifts toward a high temperature with frequency and a diffuse phase transition, indicating relaxor ferroelectric characteristics of BNKT-BST ceramics, which is confirmed by the modified Curie-Weiss law. The rhombohedral-tetragonal phase, fine grain size, and lowered Tm with relaxor properties synergistically contribute to a high Pmax and low Pr, improving the breakdown strength with BST and resulting in a high recoverable energy density Wrec of 0.81 J/cm3 and a high energy efficiency η of 86.95% at 90 kV/cm for x = 0.45. [ABSTRACT FROM AUTHOR]

The problems of biological sequence analysis have great theoretical and practical value in modern bioinformatics. Numerous solving algorithms are used for these problems, and complex similarities and differences exist among these algorithms for the same problem, causing difficulty for researchers to select the appropriate one. To address this situation, combined with the formal partition-and-recur method, component technology, domain engineering, and generic programming, the paper presents a method for the development of a family of biological sequence analysis algorithms. It designs highly trustworthy reusable domain algorithm components and further assembles them to generate specifific biological sequence analysis algorithms. The experiment of the development of a dynamic programming based LCS algorithm family shows the proposed method enables the improvement of the reliability, understandability, and development efficiency of particular algorithms.

The development of intelligent routines to support complex decision-making is not always straight-forward. In the public service the difficulties may be related to the abundance of available data sources and the number of legal standards to be met, in addition to the need for the incorporation of transparency, auditability, standardization, and desirable reuse in the IT systems. This article presents the Domain Engineering process carried out to obtain a feature model for the implementation of a Framework that uses Artificial Intelligence for dealing with the governmental rules to support public decision-making. One highlight of the put forward framework is that it supports both, end users and IT people (i.e., experts in business and in technology), that are not experienced with intelligent techniques as well as it focuses on Compliance. For this research, the Design Science Research Methodology method was used, sorting the work into the steps of the problem identification and motivation, the definition of goals, the design and development, the verification and validation of the experiments, and the communication of the results. A systematic review identifying the lack of an AI Framework in the Public Sector was carried out beforehand. The research produced a Whitebox Framework aiming to supply recommendations for both groups of users based on solutions that have already been tested and applied to know problems in their respective areas, e.g., anomaly detection, fraud identification, rule extraction, and risk management, among others focused on Compliance. Moreover, the framework was built so that it can be evolved by experts with due use.

Objectives. In many laboratories around the world, work is underway in the field of domain engineering of ferroelectrics. For a number of years, RTU MIREA has been conducting research on the creation of a high-performance technology for the formation of ferroelectric photonic and phononic crystals. The technology is characterized by a short duration of the technological cycle and provides the necessary depth of spatially periodic domain inversion. The key element of the technology is the combined effect of a uniform electric field and interfering high-frequency elastic waves that create a temperature grating. The technology is universal in relation to ferroelectrics of varying degrees of acoustic transparency, which is achieved by using highly dissipative liquid electrodes of a certain thickness. In this case, the energy of elastic waves practically does not penetrate into the ferroelectric, so the manifestation of undesirable effects is excluded. The purpose of this review article is to analyze the results of work carried out at RTU MIREA in the field of technology for the formation of ferroelectric regular domain structures (RDSs) during the period from 2008 to the present.Methods. Provisions of the theory of propagation, refraction and interference of elastic waves in condensed media are used, in particular, the Newtonian model of a liquid as applied to shear waves, as well as computer simulation. When considering the main stages of the Double Pulse heterothermal technology for the formation of RDSs, methods of analysis and synthesis were applied.Results. The possibility of forming not only micro-, but also submicron RDSs is shown. Recommendations are given on the choice of the type and specific properties of liquid electrodes, the angles between the direction of propagation of interfering waves, and their frequency. It is shown, in particular, that the use of highly dissipative ionic liquids as liquid electrodes creates favorable conditions for the formation of an RDS with a short period at room temperature. Thus, on shear waves with electrodes based on LiPF6-PC at a frequency of 300 MHz, RDS with a period of about 2 цт can be created. The main technological parameters are determined both for the case of the action of longitudinal elastic waves and for the case of shear waves with horizontal polarization. The results are applicable to ferroelectrics such as lithium niobate, potassium titanyl phosphate, and lead zirconate titanate.Conclusions. The proposed and studied methods are focused on the mass production of devices based on RDSs, in particular, on the manufacturing of optical parametric oscillators, acoustoelectronic devices, as well as terahertz wave generators and second harmonic oscillators. The technology has a short duration of the technological cycle, comparable to the polarization switching time in the used ferroelectric.

Previous experiments with barium titanate crystals have shown that electric field applied in the vicinity of its ferroelectric phase transition can be used to introduce peculiar ferroelectric domain walls, persisting to the ambient conditions: head‐to‐head charged walls compensated by the 2D electron gas. The present in situ optical observations allow the documentation of the early stage of this poling process in which the cubic and ferroelectric phases coexist, the latter being broken into multiple martensitic superdomains, separated by superdomain boundaries. It is revealed that the transient superdomains are subsequently converted into the regular ferroelectric domains, while the superdomain boundaries transform into the desired charged domain walls. In order to assign the observed transient domain patterns, to understand the shapes of the observed ferrolectric precipitates and their agglomerates as well as to provide the overall interpretation of the recorded domain formation process, the implications of the mechanical compatibility of the coexisting superdomain states are derived in the framework of the Wechsler–Lieberman–Read theory. These results also suggest that both the electric conductivity and interlinked motion of the superdomain boundaries and phase fronts are involved in the transport of the compensating charge carriers toward the charged domain wall location. [ABSTRACT FROM AUTHOR]

Abstract Previous experiments with barium titanate crystals have shown that electric field applied in the vicinity of its ferroelectric phase transition can be used to introduce peculiar ferroelectric domain walls, persisting to the ambient conditions: head‐to‐head charged walls compensated by the 2D electron gas. The present in situ optical observations allow the documentation of the early stage of this poling process in which the cubic and ferroelectric phases coexist, the latter being broken into multiple martensitic superdomains, separated by superdomain boundaries. It is revealed that the transient superdomains are subsequently converted into the regular ferroelectric domains, while the superdomain boundaries transform into the desired charged domain walls. In order to assign the observed transient domain patterns, to understand the shapes of the observed ferrolectric precipitates and their agglomerates as well as to provide the overall interpretation of the recorded domain formation process, the implications of the mechanical compatibility of the coexisting superdomain states are derived in the framework of the Wechsler–Lieberman–Read theory. These results also suggest that both the electric conductivity and interlinked motion of the superdomain boundaries and phase fronts are involved in the transport of the compensating charge carriers toward the charged domain wall location.

The development of piezoelectric ceramics with both large piezoelectric responses and mechanical quality factor is still a key challenge for practical applications for high‐power piezoelectric devices. Here we report the strategy to utilize the synergistic contribution of engineered defect and domain structure, in which an excellent piezoelectric coefficient d33 of 655 pC N−1 and mechanical quality factor Qm of 371 are simultaneously achieved in MnCO3‐modified Pb(Ni,Nb)O3–PbZrO3–PbTiO3 (Mn‐PNN–PZ–PT) ceramics. Meanwhile, the depolarization temperature (Td) and the temperature corresponding to the εr,max (Tm) are enhanced relative to the pure counterpart. After annealing at 90°C, the sample with x = 0.3 shows the retained d33 value of 610 pC N−1, about 2.6 times larger than that with x = 0 counterpart, demonstrating a wider operating temperature range. These enhanced electromechanical properties originate from the internal bias field introduced by the defect dipoles (MnZr,Ti′′−VO••)X${{\rm{(Mn}}_{{\rm{Zr,Ti}}}^{\prime\prime} - V_{\rm{O}}^{{\rm{ \bullet \bullet }}}{\rm{)}}}^X$ and (MnNb′′′−VO••)′${{\rm{(Mn}}_{{\rm{Nb}}}^{{\rm{\prime\prime\prime}}} - V_{\rm{O}}^{{\rm{ \bullet \bullet }}}{\rm{)}}}^{\rm{\prime}}$. It is verified that xMn‐PNN–PZ–PT ceramics have superior potential for high‐power application, meanwhile, paves a significant step toward enhancing the thermal stability of high‐temperature piezoceramics. [ABSTRACT FROM AUTHOR]

The processive cellulase (CelO) is an important modular enzyme of Clostridium thermocellum. To study the effect of the carbohydrate‐binding module (CBM3b) on the catalytic domain of CelO (GH5), four engineered derivatives of CelO were designed by truncation and terminal fusion of CBM3b. These are CBM at the N‐terminus, native form (CelO‐BC, 62 kDa); catalytic domain only (CelO‐C, 42 kDa); CBM at the C‐terminus (CelO‐CB, 54 kDa) and CBM attached at both termini (CelO‐BCB, 73 kDa). All constructs were cloned into pET22b (+) and expressed in Escherichia coli BL21 (DE3) star. The expression levels of CelO‐C, CelO‐CB, CelO‐BC, and CelO‐BCB were 35%, 35%, 30%, and 20%, respectively. The enzyme activities of CelO‐C, CelO‐CB, CelO‐BC, and CelO‐BCB against 1% regenerated amorphous cellulose (RAC) were 860, 758, 985, and 1208 units per μmole of the enzyme, respectively. The enzymes were partially purified from the lysate of E. coli cells by heat treatment followed by anion exchange FPLC purification. Against RAC, CelO‐C, CelO‐CB, CelO‐BC, and CelO‐BCB showed KM values of 32, 33, 45, and 43 mg⋅mL–1 and Vmax values of 3571, 3846, 3571, and 4545 U⋅min–1, respectively. CBM3b at the N‐terminus of GH5 linked through a P/T‐rich linker was found to enhance the catalytic activity and thermostability of the enzyme. [ABSTRACT FROM AUTHOR]

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The results of an experimental study of the abnormal domain structure kinetics in lithium niobate single crystals with a surface layer modified by soft proton exchange are presented. Domain switching in a wide field range allowed two qualitatively different types of domain structure evolution to be revealed: (1) the traditional growth of hexagonal domains in fields higher than 21.5 kV/mm and (2) the abnormal growth of stripe domains oriented along the Y crystallographic directions in the field range from 3.8 to 21.5 kV/mm. The stripe domains had a width up to 4 µm and depth up to 30 µm. It was shown that the time dependence of the total length of stripe domains could be analyzed in terms of the modified Kolmogorov–Avrami approach, taking into account the transition from the one-dimensional β-model to the one-dimensional α-model. The possibility of the controllable creation of a quasi-periodic structure of stripe domains with an average period of 5 µm by a two-stage polarization switching process was demonstrated. The formation and growth of stripe domains were considered in terms of the kinetic approach to the evolution of the domain structure as a result of the domain walls' motion under inefficient screening conditions caused by the presence of a modified surface layer. The abnormally low threshold fields were attributed to a presence of a "built-in" field facilitating switching, created by a composition gradient induced by soft proton exchange. [ABSTRACT FROM AUTHOR]

The practical significance of ferroelectric domains and various domain boundaries has been growing steadily in recent years. In this work, various domain structures were written with an electron beam through a thin aluminum film on a −Z cut of bulk lithium niobate. The use of relatively low accelerating voltages (5 and 10 kV) and the grounding of the surface metallization made it possible to write periodic structures (1D and 2D) on large areas with domain sizes ≤1 μm. Selective domain etching and AFM in contact mode were used to observe various domain shapes obtained in the experiments. An unusual feature of the submicron-sized domains was needle-like vertices. Importantly, the vertices of the domains were deepened relative to the irradiated surface. It was found that the size and proximity of the irradiated regions to each other in the patterns used can significantly change the upper part of the domains. The experimental data were analyzed and discussed taking into account the computer simulation of the spatial field distribution of injected electron beam charges. The obtained results contribute to the development of controlled writing of submicron-sized domain structures using an electron beam. [ABSTRACT FROM AUTHOR]

Visible‐light polarization detection is a critical challenge for next‐generation light communication and imaging technologies. While low‐dimensional nanomaterials exhibit polarization‐dependent photocurrents originating from their anisotropic absorption, ferroelectric photovoltaics provide a photocurrent derived from spatial inversion symmetry breaking. Here, it is reported that domain‐engineered ferroelectrics are promising materials for visible‐light polarization detection. Polarization angle‐resolved photocurrent measurements demonstrate that the introduction of domain walls in ferroelectric BiFe0.95Mn0.05O3 films increases the photocurrent anisotropy ratio up to 7.9 under visible light with hν = 2.4 eV (λ = 515 nm), which is much higher than that of typical nanomaterials (≈2–3). Simulations of polarization‐dependent photocurrents show that the domain walls provide an additional degree of freedom for designing ferroelectrics with quite high photocurrent anisotropy. This study opens up the possibility of developing ferrophotovoltaic‐based visible‐light polarization detectors with simple device structures. [ABSTRACT FROM AUTHOR]

With the great success on verifying its effectiveness on relaxor-PbTiO3 (PT) single crystals (SCs), alternating current poling (ACP) has been taking a center as a new domain engineering method in the last few years. Compared with the conventional direct current poling (DCP), ACP enables enhanced piezoelectric and dielectric properties. In this article, research progress in ACP and perspectives are introduced. Initially, optimized conditions of ACP for relaxor-PT SCs and unsolved issues on polycrystalline ceramics and spurious modes are reviewed. Second, the ferroelectric domain size dependence of piezoelectricity associated with ACP is discussed. We hypothesize that a tradeoff between domain and domain wall contributions exists for high piezoelectricity, suggesting an optimum 109° domain wall size, which is presumably dependent on compositions, crystallographic symmetries, and domain configurations. Finally, crystals synthesized by a solid-state crystal growth (SSCG) method are briefly introduced due to their unprecedented piezoelectricity obtained by ACP (${d}_{33} \sim 5500$ pC/N). We hope that this work helps to grasp the current status of ACP and to guide future tasks to be studied. [ABSTRACT FROM AUTHOR]

Electrostrictive effects in complex-perovskite “relaxor” ferroelectrics (FEs) exhibit superior performance in comparison with the simple-perovskite normal FEs, such as giant electrostriction in its paraelectric phase and high electromechanical coupling in its FE phase. As one of the discoverers, the author will deliver the historical background of these epoch-making phenomena and the development strategy of how we considered performance improvement. Though both discoveries were actually originated from a sort of “serendipity” (lucky & accidental occurrence!), some of the key factors have been embedded in the research base: 1) interrelation between complex perovskite structure and ferroelectricity; 2) anharmonicity in relaxor FEs; and 3) microdomain contribution in relaxor FEs. In the last part of this article, the author introduces a bit different “mesoscopic” approach, “fractal analysis of microdomain configuration” in conjunction with the “domain engineering” concept, to distinguish the electromechanical coupling among the normal and relaxor FEs for remaining the future research seeds. [ABSTRACT FROM AUTHOR]

Lead-free bulk ceramics for advanced pulse power capacitors possess low recoverable energy storage density (W rec) under low electric field. Sodium bismuth titanate (Bi 0.5 Na 0.5 TiO 3 , BNT)-based ferroelectrics have attracted great attention due to their large maximum polarization (P m) and high power density. The BNT-ST: xAlN ceramics are designed and fabricated to get high W rec and large P m under low electric field simultaneously. An excellent large P m (49.04 μC/cm2) and W rec (2.07 J/cm3) under low electric field (160 kV/cm) are acquired in BNT-ST: 0.1 wt% AlN. The domain structure evolution and polarization switching are investigated systematically using piezoresponse force microscopy (PFM). The introduction of AlN promotes the formation of thermal conductive network and the crystallization of ceramics, thus improving thermal stability and increasing P m significantly. The higher density of domain walls and the larger negative built-in voltage may be beneficial to increase breakdown field strength (E b), while the more 180° domains induce by electric field and the better domain switching behavior contribute to a significant increase in P m. The enhanced E b and super high P m are favorable for obtaining high W rec under low electric field which will boost the application of BNT-based ferroelectrics in advanced pulse power capacitors. [ABSTRACT FROM AUTHOR]

Domain orientation engineering regulates the polarization direction of thin film and facilitates the enhancement of piezoelectric properties. A change in polarization direction implies a structural change in the piezoelectric thin film. In this work, some unexpected results are obtained by preparing three orientations of Bi0.5Na0.5TiO3‐based lead‐free piezoelectric thin films to amplify this structural change. In distinction to the conventional perception, the piezoelectric properties decrease with increasing polarization direction. This anomaly is influenced by the concentration of structural defects, and rotation of the polarization direction may induce a change in the electronic structure of the material and hence in the concentration of structural defects. Ultimately, the suppression of the domain dynamics response by increasing structural defects leads to the worst piezoelectric properties for thin films with the traditionally perceived optimal (100) orientation. The revelation of this anomaly has implications for the design of the next generation of high‐performance piezoelectric thin films. [ABSTRACT FROM AUTHOR]

Relaxor ferroelectric single crystals with perovskite (ABO3) structure possess excellent electromechanical coupling properties and are considered as the key materials of next-generation medical ultrasound transducers, high-precision piezoelectric actuators, and underwater acoustic transducers. According to the existing fundamental science and material preparation issues in relaxor ferroelectric crystals, this manuscript reviews the research progresses on the crystal growth and property optimization of relaxor ferroelectric singles in recent years. This review covers the following aspects: new crystal growth methods for enhancing the uniformity of composition and properties; new methods to improve the piezoelectric properties of relaxor ferroelectric single crystals; the control of ferroelectric domain structure to achieve high-light transmittance of relaxor ferroelectric crystals; the application of high-performance relaxor ferroelectric single crystals in the field of electro-optical technology. [ABSTRACT FROM AUTHOR]

Polymers are essential components of modern-day materials and are widely used in various fields. The dielectric constant, a key physical parameter, plays a fundamental role in the light-, electricity-, and magnetism-related applications of polymers, such as dielectric and electrical insulation, battery and photovoltaic fabrication, sensing and electrical contact, and signal transmission and communication. Over the past few decades, numerous efforts have been devoted to engineering the intrinsic dielectric constant of polymers, particularly by tailoring the induced and orientational polarization modes and ferroelectric domain engineering. Investigations into these methods have guided the rational design and on-demand preparation of polymers with desired dielectric constants. This review article exhaustively summarizes the dielectric constant engineering of polymers from molecular to mesoscopic scales, with emphasis on application-driven design and on-demand polymer synthesis rooted in polymer chemistry principles. Additionally, it explores the key polymer applications that can benefit from dielectric constant regulation and outlines the future prospects of this field., (© 2023 Wiley‐VCH GmbH.)

This article proposes a process for digital innovation platforms in the energy sector called DINNPU The work methodology involves the documentary review of research in the field of innovation, transformation, and digital platforms capable of generating value and innovation to its ecosystem; in this way, a conceptual and theoretical basis was generated that allowed the formalization of the disciplines for the design of digital innovation platforms. Thus, the process proposed here, can be used in the development approach for these innovation platforms and can be instantiated for a specific domain in which case, the assets produced can be reused to generate a product from a family of domains. The main disciplines of this process are analysis, design and implementation of digital platforms. For the case study, an interview was conducted with a group of specialists in the ICT area of an energy company (Utilities), in order to understand the digitization process or current maturity of this company. Then it was validated whether the proposed model or design is applicable or should wait until the company achieves the necessary digital maturity. The contribution of this work is to propose a process for domain engineering, which allows to contribute with knowledge and experience, for digital innovation platforms in the energy industry, in an area quite incipient in the Chilean environment.

This paper presents a new modeling method to abstract the collective behavior of Smart IoT Systems in CPS, based on process algebra and a lattice structure. In general, process algebra is known to be one of the best formal methods to model IoTs, since each IoT can be represented as a process; a lattice can also be considered one of the best mathematical structures to abstract the collective behavior of IoTs since it has the hierarchical structure to represent multi-dimensional aspects of the interactions of IoTs. The dual approach using two mathematical structures is very challenging since the process algebra have to provide an expressive power to describe the smart behavior of IoTs, and the lattice has to provide an operational capability to handle the state-explosion problem generated from the interactions of IoTs. For these purposes, this paper presents a process algebra, called dTP-Calculus, which represents the smart behavior of IoTs with non-deterministic choice operation based on probability, and a lattice, called n:2-Lattice, which has special join and meet operations to handle the state explosion problem. The main advantage of the method is that the lattice can represent all the possible behavior of the IoT systems, and the patterns of behavior can be elaborated by finding the traces of the behavior in the lattice. Another main advantage is that the new notion of equivalences can be defined within n:2-Lattice, which can be used to solve the classical problem of exponential and non-deterministic complexity in the equivalences of Norm Chomsky and Robin Milner by abstracting them into polynomial and static complexity in the lattice. In order to prove the concept of the method, two tools are developed based on the ADOxx Meta-Modeling Platform: SAVE for the dTP-Calculus and PRISM for the n:2-Lattice. The method and tools can be considered one of the most challenging research topics in the area of modeling to represent the collective behavior of Smart IoT Systems. [ABSTRACT FROM AUTHOR]

In recent years, polar topological textures like skyrmions and vortices in ferroelectric superlattices and multilayers have received extensive attention. However, the polar topological textures in these systems suffer strong interactions and are difficult to be manipulated as individual elements, limiting their application prospects in storage and logic devices. Here, via phase field simulations, we demonstrate domain engineering as a feasible strategy to create diverse weakly correlated polar topological texture arrays in single-layer tetragonal ferroelectric thin films, including Néel-type skyrmions with positive/negative topological charges and Bloch-type skyrmions with different chirality. We calculate the stability phase diagram and reveal the evolution characteristics of these polar topological textures under local electric and mechanical stimuli. We realize local erasing and writing of single Néel- and Bloch-type skyrmions, as well as deterministic chirality control of single Bloch-type skyrmion, confirming the weak correlation of the polar skyrmions. Our study therefore demonstrates domain engineering as an effective strategy for stabilizing weakly correlated polar topological textures, which extends the existence system of polar topological textures and paves a new way for the design of storage and logic devices based on polar topological textures. [Display omitted] [ABSTRACT FROM AUTHOR]

Domain engineering in ferroelectrics endows flexibility for different functional applications. Whereas the domain engineering strategy for single crystals and thin films is diverse, there is only a limited number of strategies for bulk ceramics. Here, a domain engineering strategy for achieving a compact domain architecture with increased domain‐wall density in (K,Na)NbO3 (KNN)‐based ferroelectric ceramics via mesoscopic chemical inhomogeneity (MCI) is developed. The MCI‐induced interfaces can effectively hinder domain continuity and modify the domain configuration. Besides, the MCI effect also results in diffused phase transitions, which is beneficial for achieving enhanced thermal stability. Modulation of chemical inhomogeneity demonstrates great potential for engineering desirable domain configuration and properties in ferroelectric ceramics. Additionally, the MCI can be easily controlled by regulating the processing condition during solid‐state synthesis, which is advantageous to industrial production. [ABSTRACT FROM AUTHOR]

A method is proposed for formation of regular domain structures in ferroelectrics using interfering laser beams, a uniform electric field, and liquid electrodes with a giant extinction coefficient. It is shown that when using liquid electrodes, for example, based on a CdI2 aqueous solution with a 248 ÷ 266 nm photonic band gap, it is possible to create domain structures with a period of 6 ÷ 8 µm. The method is versatile for ferroelectrics of various degrees of transparency and birefringence, and is also characterized by a short duration of the process of formation of structures in ferroelectrics, such as LiNbO3, KTiOPO4, and PZT. [ABSTRACT FROM AUTHOR]

Domain growth and shape evolution during local switching under the action of biased conductive tip of scanning probe microscope were studied in Z + cut lithium niobate on insulator (LNOI) with 1 µm-thick SiO2 layer between LN film and grounded electrode. Piezoresponse force microscopy and confocal Raman microscopy were used for domain imaging. The domain shape evolution during switching was qualitatively reconstructed. The crucial role of discrete switching on the kinetics of domain growth was revealed. The stability of the switched domains was confirmed. The obtained knowledge will be used for creation of the periodical domain structures by local switching. [ABSTRACT FROM AUTHOR]

Abstract Domain engineering in ferroelectrics endows flexibility for different functional applications. Whereas the domain engineering strategy for single crystals and thin films is diverse, there is only a limited number of strategies for bulk ceramics. Here, a domain engineering strategy for achieving a compact domain architecture with increased domain‐wall density in (K,Na)NbO3 (KNN)‐based ferroelectric ceramics via mesoscopic chemical inhomogeneity (MCI) is developed. The MCI‐induced interfaces can effectively hinder domain continuity and modify the domain configuration. Besides, the MCI effect also results in diffused phase transitions, which is beneficial for achieving enhanced thermal stability. Modulation of chemical inhomogeneity demonstrates great potential for engineering desirable domain configuration and properties in ferroelectric ceramics. Additionally, the MCI can be easily controlled by regulating the processing condition during solid‐state synthesis, which is advantageous to industrial production.