3D Reconstruction of Sawtooth 180° Tail-to-Tail Domain Walls in Single Crystal BiFeO3

Previous studies of single crystal BiFeO₃ have found a dense domain structure with alternating sawtooth and flat domain walls (DWs). The nature of these domains and their 3D structure has remained elusive to date. Herein, several sections taken at different orientations are used to examine the structure in detail, concentrating here on the sawtooth DWs using diffraction contrast transmission electron microscopy, electron diffraction, and aberration-corrected scanning transmission electron microscopy (STEM). All DWs are found to be 180° type; the flat walls have head-to-head polarity while the sawtooth DWs are tail-to-tail with peaks elongated along the polar [111] axis, formed by neutral ($11\overline{2}$) DW facets and slightly charged facets with orientations close to ($3\overline{2}1$) and ($\overline{2}31$). The neutral DW facets are Ising type and very abrupt, while the charged DW facets have mixed Néel/Bloch/Ising character with a chiral nature and a width of about 2 nm.     

Promoting “Strong Adsorption” and “Fast Conversion” of Polysulfides in Li-S batteries Based on Conductive Sulfides Host with Hollow Prism Structure and Surface Defects

The chemical binding between metal compounds and polysulfides provides a good solution to inhibit shuttle effect in Li-S batteries. However, the Sabatier principle predicts that overly strong adsorption will commonly hinder the conversion of polysulfides, so building the synergetic effect mechanism between “strong adsorption” and “fast conversion” for polysulfides is a significant strategy. To realize this goal, in this study, the defect-enriched Co₉S₈ hollow prisms (DHCPs) as both S host and catalyst material for Li-S batteries are designed. Based on in situ UV–vis spectroscopy results, it is found that DHCPs can profitably promote the generation of ${\mathrm{S}}_3^{·-}$ radicals during the discharge process. In the case of the relatively high conversion barrier of “liquid–liquid” reaction, the generated ${\mathrm{S}}_3^{·-}$ radicals are responsible for the fast conversion reaction via a unique reaction pathway. When the sulfur loading is 4.63 mg cm⁻², the cell with DHCP/S cathode delivers a high areal capacity of 4.75 mAh cm⁻² at 0.1 C and keeps a high capacity of 2.99 mAh cm⁻² after 100 cycles at 0.5 C. This study provides a positive attempt to achieve “strong adsorption” and “fast conversion” of polysulfides simultaneously, which will convincingly boost the development and practical process of Li-S batteries.     

Does Salt Concentration Matter? New Insights on the Intercalation Behavior of PF6−${\rm{PF}}_6^ - $ into Graphite Cathode for the Dual-Ion Battery

A high-concentration electrolyte is favored in dual-ion batteries (DIBs) due to the lower onset potential for anion intercalation, higher specific discharge capacity, and better oxidation stability. Inspired by the correlation between the high-concentration electrolytes and localized high-concentration electrolytes, it is suspected that it is not the salt concentration but the solution structure of the electrolyte that determines the intercalation behavior of anion into graphite cathode. To prove the viewpoint, a series of electrolytes are prepared by controlling the salt concentration or solution structure and the intercalation behavior of $P{F}_6^{-}$ within the graphite cathode is investigated in Li||graphite and graphite||graphite cells. It is found that $P{F}_6^{-}$ anions exhibit similar onset potentials and specific discharge capacities in the electrolytes with different salt concentrations but similar solution structures. This study provides a new perspective on designing promising electrolytes for DIBs, which can accelerate the further exploitation of high-performance DIBs.     

Incommensurate Magnetic Order in Hole-Doped Infinite-Layer Nickelate Superconductors due to Competing Magnetic Interactions

The discovery of superconductivity in hole-doped infinite-layer nickelates has fueled intense research to identify the critical factor responsible for high-T_c superconductivity. Magnetism and superconductivity are closely entangled, and elucidating the magnetic interactions in hole-doped nickelates is critical for understanding the pairing mechanism. Here, these calculations based on the generalized Bloch theorem (GBT) and magnetic force theorem (MFT) consistently reveal that hole doping stabilizes an incommensurate (IC) spin state and increases the IC wave vector continuously, in a way strikingly similar to hole-doped cuprates. Going further, a nonlinear Heisenberg model including first-neighbor and third-neighbor in-plane magnetic interactions is developed. The analytical solutions successfully reproduce GBT and MFT results and reveal that the competition between the two magnetic interactions is the decisive factor for the IC magnetic transition. Eventually, by analyzing the doping-controlled spin splitting of $d_{x^2-y^2}$ band and orbital-contributed exchange interactions, direct links between hole doping, magnetization, exchange constants, and magnetic order are established. This discovery of the IC spin state, new understanding of its electronic origin, and establishment of direct connection with the paring $d_{x^2-y^2}$ electrons radically change the current understanding of the magnetic properties in hole-doped NdNiO₂ and open new perspectives for the superconducting mechanism in nickelates superconductors.     

Giant Electric Field-Induced Strain with High Temperature-Stability in Textured KNN-Based Piezoceramics for Actuator Applications

Large-strain (K,Na)NbO₃ (KNN) based piezoceramics are attractive for next-generation actuators because of growing environmental concerns. However, inferior performance with poor temperature stability greatly hinders their industrialized procedure. Herein, a feasible strategy is proposed by introducing ${\mathrm{V}}_{\text{K/Na}}^{{}^{\prime }}$-${\mathrm{V}}_{\stackrel{\mathrm{..}}{\mathrm{O}}}$ defect dipoles and constructing grain orientation to enhance the strain performance and temperature stability of KNN-based piezoceramics. This textured ceramics with 90.3% texture degree exhibit a giant strain (1.35%) and a large converse piezoelectric coefficient d₃₃^* (2700 pm V⁻¹), outperforming most lead-free piezoceramics and even some single crystals. Meanwhile, the strain deviation at high temperature of 100 °C–200 °C is obviously alleviated from 61% to 35% through texture engineering. From the perspective of practical applications, piezo-actuators are commonly utilized in the form of multilayer. In order to illustrate the applicability on multilayer actuators, a stack-type actuator consisted of 5 layers of 0.4 mm thick ceramics is fabricated. It can generate large field-induced displacement (11.6 µm), and the promising potential in precise positioning and optical modulation are further demonstrated. This work provides a textured KNN-based piezoceramic with temperature-stable giant strain properties, and facilitates the lead-free piezoceramic materials in actuator applications.     

Ferroelectric Control of Polarity of the Spin-polarized Current in Van Der Waals Multiferroic Heterostructures

Ferroelectric (FE) control of magnetism at nanoscale, for instance, FE control of the polarity of spin-polarized current is crucial for technological advances in magnetoelectric and spintronic applications. However, this fascinating functionality has not been reported in nanoscale systems yet. Herein, a new class of FE/A-type antiferromagnetic heterobilayer/FE van der Waals (vdW) multiferroic structures is found, in which the FE control of polarity of spin-polarized current is found possible. Take Sc₂CO₂/CrSiTe₃/CrGeTe₃/Sc₂CO₂ heterostructure as a successful example. First-principles calculations reveal that its polarity of half-metallicity can be switched by flipping the FE polarization orientation. Meanwhile, device transport simulation shows that its up/down spin current transmission ratio is as large as 0.1 × 10³ at $\overrightarrow{\mathrm{P}}\uparrow \uparrow$ Sc₂CO₂ configuration and is only 2.6 × 10⁻³ at $\overrightarrow{\mathrm{P}}\downarrow \downarrow$ Sc₂CO₂ configuration in the vdW multiferroic heterostructures. Essentially, it stems from the reversible FE switch of the internal electric field across the CrSiTe₃/CrGeTe₃ heterobilayer and the FE control of the interfacial effect between Sc₂CO₂ and Cr(Si/Ge)Te₃ layers. This work opens a direction for constructing low-energy-dissipation, non-volatile, and high-sensitive spintronic devices such as spin field-effect transistors.     

Calibration-Free and High-Sensitivity Microwave Detectors Based on InAs/InP Nanowire Double Quantum Dots

At the cutting-edge of microwave detection technology, novel approaches which exploit the interaction between microwaves and quantum devices are rising. In this study, microwaves are efficiently detected exploiting the unique transport features of InAs/InP nanowire double quantum dot-based devices, suitably configured to allow the precise and calibration-free measurement of the local field. Prototypical nanoscale detectors are operated both at zero and finite source-drain bias, addressing and rationalizing the microwave impact on the charge stability diagram. The detector performance is addressed by measuring its responsivity, quantum efficiency and noise equivalent power that, upon impedance matching optimization, are estimated to reach values up to ≈2000 A W⁻¹, 0.04 and ≈${10}^{-16}\mathrm{W}/\sqrt{Hz}$, respectively. The interaction mechanism between the microwave field and the quantum confined energy levels of the double quantum dots is unveiled and it is shown that these semiconductor nanostructures allow the direct assessment of the local intensity of the microwave field without the need for any calibration tool. Thus, the reported nanoscale devices based on III-V nanowire heterostructures represent a novel class of calibration-free and highly sensitive probes of microwave radiation, with nanometer-scale spatial resolution, that may foster the development of novel high-performance microwave circuitries.     

Multipoint Defect Synergy Realizing the Excellent Thermoelectric Performance of n‐Type Polycrystalline SnSe via Re Doping

SnSe has attracted much attention due to the excellent thermoelectric (TE) properties of both p‐ and n‐type single crystals. However, the TE performance of polycrystalline SnSe is still low, especially in n‐type materials, because SnSe is an intrinsic p‐type semiconductor. In this work, a three‐step doping process is employed on polycrystalline SnSe to make it n‐type and enhance its TE properties. It is found that the Sn_0.97Re_0.03Se_0.93Cl_0.02 sample achieves a peak ZT value of ≈1.5 at 798 K, which is the highest ZT reported, to date, in n‐type polycrystalline SnSe. This is attributed to the synergistic effects of a series of point defects: $V_{\mathrm{Se}}^{\mathrm{..}},{\mathrm{Cl}}_{\mathrm{Se}}^{.},V_{\mathrm{Sn}}^{,,},{\mathrm{Re}}_{\mathrm{Sn}}^{\times },{\mathrm{Re}}_{}^0$. In those defects, the $V_{\mathrm{Se}}^{\mathrm{..}}$ compensates for the intrinsic Sn vacancies in SnSe, the ${\mathrm{Cl}}_{\mathrm{Se}}^{.}$ acts as a donor, the $V_{\mathrm{Sn}}^{,,}$acts as an acceptor, all of which contribute to optimizing the carrier concentration. Rhenium (Re) doping surprisingly plays dual‐roles, in that it both significantly enhances the electrical transport properties and largely reduces the thermal conductivity by introducing the point defects, ${\mathrm{Re}}_{\mathrm{Sn}}^{\times },{\mathrm{Re}}_{}^0$. The method paves the way for obtaining high‐performance TE properties in SnSe crystals using multipoint‐defect synergy via a step‐by‐step multielement doping methodology.     

Limitations of the Tauc Plot Method

The Tauc plot is a method originally developed to derive the optical gap of amorphous semiconductors such as amorphous germanium or silicon. By measuring the absorption coefficient α(hν) and plotting ${(\alpha hv)}^{\frac{1}{2}}$ versus photon energy hν, a value for the optical gap (Tauc gap) is determined. In this way non-direct optical transitions between approximately parabolic bands can be examined. In the last decades, a modification of this method for (poly-) crystalline semiconductors has become popular to study direct and indirect interband transitions. For this purpose, (ahν)ⁿ (n = $\frac{1}{2}$, 2) is plotted against hν to determine a value of the electronic bandgap. Due to the ease of performing UV–vis measurements, this method has nowadays become a standard to analyze various (poly-) crystalline solids, regardless of their different electronic structure. Although this leads partially to widely varying values of the respective bandgap of nominally identical materials, there is still no study that critically questions which peculiarities in the electronic structure prevent a use of the Tauc plot for (poly-) crystalline solids and to which material classes this applies. This study aims to close this gap by discussing the Tauc plot and its limiting factors for exemplary (poly-) crystalline solids with different electronic structures.     

A Near-Surface Structure Reconfiguration Strategy to Regulate Mn3+/Mn4+ and O2−/(O2)n− Redox for Stabilizing Lithium-Rich Oxide Cathode

Lithium-rich layered oxides (LROs) are one class of the most competitive high-capacity cathode materials due to their anion/cation synergistic redox activity. However, excessive oxidation of the oxygen sublattices can induce serious oxygen loss and structural imbalance. Hence, a near-surface reconfiguration strategy by fluorinating graphene is proposed to precisely regulate Mn³⁺/Mn⁴⁺ and O²⁻/(O₂)ⁿ⁻ redox couples for remarkably stabilizing high-capacity LROs and realizing the simultaneous reduction of the lattice stress, regulation of the Mn metal at a lower charge state, and construction of 3D Li⁺ diffusion channels. Combining with a highly conductive graphene-coating layer, the surface oxygen loss, transition metal dissolution, and electrolyte catalytic decomposition are suppressed. Benefiting from this synergy, the modified LROs disclose higher initial Coulombic efficiency and discharge-specific capacity and improve cyclability compared with pristine LROs. Further, it is revealed that the F⁻ impact becomes easier for the O sites at the lattice interface of C2/m and R$\overline{3}$m to sufficiently buffer lattice stress. Moreover, lithium ions coupled to the doped F atoms at the lattice interface migrate to the Ni-rich R$\overline{3}$m lattice sites with lower migration energies. This consolidated understanding will open new avenues to regulate reversible oxygen redox of LROs for high-energy-density lithium-ion batteries.     

Strain Anisotropy Driven Spontaneous Formation of Nanoscrolls from 2D Janus Layers

2D Janus transition metal dichalcogenides (TMDs) have attracted attention due to their emergent properties arising from broken mirror symmetry and self-driven polarization fields. While it has been proposed that their vdW superlattices hold the key to achieving superior properties in piezoelectricity and photovoltaic, available synthesis has ultimately limited their realization. Here, the first packed vdW nanoscrolls made from Janus TMDs through a simple one-drop solution technique are reported. The results, including ab initio simulations, show that the Bohr radius difference between the top sulfur and the bottom selenium atoms within Janus ${\mathrm{M}}_{\mathrm{Se}}^{\mathrm{S}}$ (M = Mo, W) results in a permanent compressive surface strain that acts as a nanoscroll formation catalyst after small liquid interaction. Unlike classical 2D layers, the surface strain in Janus TMDs can be engineered from compressive to tensile by placing larger Bohr radius atoms on top (${\mathrm{M}}_{\mathrm{S}}^{\mathrm{Se}})$to yield inverted C scrolls. Detailed microscopy studies offer the first insights into their morphology and readily formed Moiré lattices. In contrast, spectroscopy and FETs studies establish their excitonic and device properties and highlight significant differences compared to 2D flat Janus TMDs. These results introduce the first polar Janus TMD nanoscrolls and introduce inherent strain-driven scrolling dynamics as a catalyst to create superlattices.     

Layer Sliding And Twisting Induced Electronic Transitions In Correlated Magnetic 1t-Nbse2 Bilayers

Correlated 2D layers, like 1T-phases of TaS₂, TaSe₂, and NbSe₂, exhibit rich tunability through varying interlayer couplings, which promotes the understanding of electron correlation in the 2D limit. However, the coupling mechanism is, so far, poorly understood and is tentatively ascribed to interactions among the ${\mathrm{d}}_{{\mathrm{z}}^2}$orbitals of Ta or Nb atoms. Here, it is theoretically shown that the interlayer hybridization and localization strength of interfacial Se p_z orbitals, rather than Nb ${\mathrm{d}}_{z^2}$orbitals, govern the variation of electron-correlated properties upon interlayer sliding or twisting in correlated magnetic 1T-NbSe₂ bilayers. Each of the layers is in a star-of-David (SOD) charge-density-wave phase. Geometric and electronic structures and magnetic properties of 28 different stacking configurations are examined and analyzed using density-functional-theory calculations. It is found that the SOD contains a localized region, in which interlayer Se p_z hybridization plays a paramount role in varying the energy levels of the two Hubbard bands. These variations lead to three electronic transitions among four insulating states, which demonstrate the effectiveness of interlayer interactions to modulate correlated magnetic properties in a prototypical correlated magnetic insulator.     

Single-Orientation Epitaxy of Quasi-1D Tellurium Nanowires on M-Plane Sapphire for Highly Uniform Polarization Sensitive Short-Wave Infrared Photodetection

Tellurium (Te), an elemental van der Waals semiconductor, has intriguing anisotropic physical properties owing to its inherent quais-1D crystal structure. Synthesizing ultrathin Te crystal with uniform orientation is important to its large-scale device applications, but that remains a great challenge. Herein, the nanoscale grooves-induced unidirectional epitaxy growth of 1D Te nanowires via physical vapor deposition on the annealed m-plane sapphire is demonstrated. By enhancing the annealing temperature from 1000 to 1300 °C, nanoscale grooves on m-plane sapphire arising along the [10$\overline{1}$0] direction and gradually distinct, and the corresponding Te nanowires grown on them turns from random to uniform, finally achieving nearly 95% unidirectional Te nanowires. The as-grown Te nanowires possess high crystallinity with clearly chiral helical chains along the c-axis direction and reveal thickness-tunable bandgap with prominent linear-dichroic. As results, the Te nanowire-based photodetectors demonstrate a broadband photoresponse from visible (532 nm) to short-wave infrared (2530 nm), with high responsivity of 327 A W⁻¹ as well as strong and uniform polarization sensitivity (anisotropic ratio = 2.05) to 1550 nm light. The high crystallinity and superior anisotropy of Te nanowires, combined with the orientation-controlled preparation endows it with great feasibility for constructing chip-scale multifunctional optoelectronic devices.     

Macroscopic and Microscopic Structures of Cesium Lead Iodide Perovskite from Atomistic Simulations

A first‐principles‐based effective Hamiltonian is developed and employed to investigate finite‐temperature structural properties of a prototype of perovskite halides, that is CsPbI₃. Such simulations, when using first‐principles‐extracted coefficients, successfully reproduce the existence of an orthorhombic Pnma state and its iodine octahedral tilting angles around room temperature. However, they also yield a direct transformation from Pnma to cubic $Pm\overline{3}m$ upon heating, unlike measurements that reported the occurrence of an intermediate long‐range‐tilted tetragonal P4/mbm phase in‐between the orthorhombic and cubic phases. Such disagreement, which may cast some doubts about the extent to which first‐principle methods can be trusted to mimic hybrid perovskites, can be resolved by “only” changing one short‐range tilting parameter in the whole set of effective Hamiltonian coefficients. In such a case, some reasonable values of this specific parameter result in the predictions that i) the intermediate P4/mbm state originates from fluctuations over many different tilted states; and ii) the cubic $Pm\overline{3}m$ phase is highly locally distorted and develops strong transverse antiphase correlation between first‐nearest neighbor iodine octahedral tiltings, before undergoing a phase transition to P4/mbm under cooling.     

Enhanced Stability and Narrowed D-Band Gap of Ce-Doped Co3O4 for Rechargeable Aqueous Zn-Air Battery

It remains challenging to achieve further breakthroughs in the development of durable bifunctional air cathode electrocatalysts for increasing the cycling life of rechargeable Zn-air battery (RZAB). Herein, d-band gap narrowing strategy is proposed to significantly boost the electrocatalytic activity and stability of spinel Co₃O₄ for both oxygen reduction and evolution reactions. In situ Raman spectroscopy finds that the Ce atom substitution can significantly improve the durability and corrosion resistance of electrocatalysts in harsh alkaline electrolytes. Synchrotron X-ray absorption fine structure reveals that the Co³⁺/Co²⁺ ratio of Co₃O₄ can be tuned with Ce introduction, which is beneficial to optimize the adsorption/desorption of the intermediates over Co_oh³⁺ active sites. Density functional theory calculations further confirm the reduced gap between Co d-band and O p-band centers, increased electrical conductivity, together with the deepened valence band maximum of Co sites in Ce-doped Co₃O₄. Thereby, the optimized RZAB with Ce-Co₃O₄ delivers excellent long-term durability (290 h) and large specific capacity (876.3 $Whk{g}_{Zn}^{-1}$), which possesses great prospects in all-solid-state flexible RZAB devices.     

Achieving Large Second Harmonic Generation Effects via Optimal Planar Alignment of Triangular Units

Trigonal planar units with large polarizability anisotropy and high physicochemical stability are ideal structural units for exploring nonlinear optical (NLO) materials. Integrating the merits of two types of triangular-like moieties, a family of second-order NLO-active hybrid halides, MATX (X = Cl (1), Br ( 2 ), and I ( 3 )), are achieved. MATX crystallizes in a nonpolar space group of $P\overline{6}$2c but exhibits the optimal spatial arrangement and superior NLO performance. The low coordination planar trigonal AgX₃ units enable segregation in layers of the three-winged propeller-like Me₃TPA units. All of the layers are packed in a perfect parallel fashion, making the functional materials exhibit superior NLO performances, including the phase matchable behavior with strong SHG responses (6.2/ 1 , 6.5/ 2, and 7.6/ 3 times that of potassium dihydrogen phosphate), large birefringence (0.232/ 1 , 0.252/ 2 and 0.260/ 3 at 1064 nm), high laser damage threshold, wide transparent window, and easiness of crystal growth. The first-principles calculations reveal that the coexistence of strong linear and nonlinear optical properties are ascribed to the synergistic effect of the trigonal moieties. This study points out a useful path for the rational design of excellent NLO materials.     

Interfacial and Bulk Magnetic Properties of Stoichiometric Cerium Doped Terbium Iron Garnet Polycrystalline Thin Films

One of the best magneto‐optical claddings for optical isolators in photonic integrated circuits is sputter deposited cerium‐doped terbium iron garnet (Ce:TbIG) which has a large Faraday rotation (≈?3500° cm^?1 at 1550 nm). Near‐ideal stoichiometry $\left(\frac{\text{Ce}+\text{Tb}}{\text{Fe}}=0.57\right)$ of Ce_0.5Tb_2.5Fe_4.75O₁₂ is found to have a 44 nm magnetic dead layer that can impede the interaction of propagating modes with garnet claddings. The effective anisotropy of Ce:TbIG on Si is also important, but calculations using bulk thermal mismatch overestimate the effective anisotropy. Here, X‐ray diffraction measurements yield highly accurate measurements of strain that show anisotropy favors an in‐plane magnetization in agreement with the positive magnetostriction of Ce:TbIG. Upon doping TbIG with Ce, a slight decrease in compensation temperature occurs which points to preferential rare‐earth occupation in dodecahedral sites and an absence of cation redistribution between different lattice sites. The high Faraday rotation, large remanent ratio, large coercivity, and preferential in‐plane magnetization enable Ce:TbIG to be an in‐plane latched garnet, immune to stray fields with magnetization collinear to direction of light propagation.     

2D Porous Polymers with sp2‐Carbon Connections and Sole sp2‐Carbon Skeletons

2D porous polymers with a planar architecture and high specific surface area have significant applications potential, such as for photocatalysis, electrochemical catalysis, gas storage and separation, and sensing. Such 2D porous polymers have generally been classified as 2D metal–organic frameworks, 2D covalent organic frameworks, graphitic carbon nitride, graphdiyne, and sandwich‐like porous polymer nanosheets. Among these, 2D porous polymers with sp²‐hybridized carbon ( $C_{s{p}^2}$) bonding are an emerging field of interest. Compared with 2D porous polymers linked by B? O, C?N, or C?C bonds, $C_{s{p}^2}$‐linked 2D porous polymers exhibit extended electron delocalization resulting in unique optical/electrical properties, as well as high chemical/photostability and tunable electrochemical performance. Furthermore, such 2D porous polymers are one of the best precursors for the fabrication of 2D porous carbon materials and carbon skeletons with atomically dispersed transition‐metal active sites. Herein, rational synthetic approaches for 2D porous polymers with $C_{s{p}^2}$ bonding are summarized. Their current practical photoelectric applications, including for gas separation, luminescent sensing and imaging, electrodes for batteries and supercapacitors, and photocatalysis are also discussed.     

Giant Piezoelectricity of Ternary Perovskite Ceramics at High Temperatures

Here, novel ferroelectric ceramics of (0.95 ? x)BiScO₃‐xPbTiO₃‐0.05Pb(Sn_1/3Nb_2/3)O₃ (BS‐xPT‐PSN) of complex perovskite structure are reported with compositions near the morphotropic phase boundary (MPB), and which exhibit a piezoelectric coefficient d₃₃ = 555 pC N^?1, a large‐signal coefficient $d_{33}^{?}$ ≈ 1200 pm V^?1 at room temperature, and a high Curie temperature T_C of 408 °C. More interestingly, this ternary system exhibits a giant and stable piezoelectric response at 200 °C with a large‐signal $d_{33}^{?}$ ≈ 2500 pm V^?1, matching that of the costly relaxor‐based piezoelectric single crystals at room temperature. The mechanisms of such giant piezoelectricity and its characteristic temperature dependence are attributed to the spontaneous polarization rotation and extension under an electric field and the MPB‐related phase transition. The findings reveal that the BS‐xPT‐PSN ceramics constitute a new family of high‐performance piezoelectric materials suitable for electromechanical transducers that can be operated at high temperatures (at 200 °C, or higher).