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The study on piezoelectric and ferroelectric properties of sodium bismuth titanate-based materials is essential for piezoelectric electronic components. In this study, a series of lead-free relaxor ferroelectric (1− x)Bi 0.5 Na 0.5 TiO 3 - x BaSnO 3 (BNT- x BS) ceramics were prepared by a conventional solid-state reaction method. The phase performance, fracture morphologies, permittivity, ferroelectricity, piezoelectricity, and thermal expansion for various BS contents (x) were systematically studied. With an increase in x , the phase transition from R 3 c to P 4 bm , and the grain size marginally decreased from 1.79 to 1.51 μm. Meanwhile, the degree of dielectric relaxor and diffused phase transition improved, and the ferroelectricity and piezoelectricity initially increased and then decreased. The optimal electrical properties of P r = 41.6 μC/cm2, d 33 = 167.8 pC/N, and k p = 0.318 were observed at x = 0.06. The paper discusses how site disorder, long-range electric dipole ordering, and grain size influence various electrical properties. The mechanism of the thermal expansion behaviour was investigated based on Born-Lande theory. This study could serve as a landmark for studying multifunctional BNT-based piezoelectric materials for potential energy-harvesting devices. • BaSnO 3 could induce phase transition of R 3 c to P 4 bm in BNT-based ceramics. • Ceramics exhibited a high densification with a grain size of approximately 1.7 μm. • Diffused phase transition and relaxor degree enhanced with increasing x. • Influencing factors of site and long-range electric dipole order were discussed. • Mechanism of thermal expansion behaviour was studied using Born-Lande theory. [ABSTRACT FROM AUTHOR]

• Establishment of a precise physical foundation for the negative capacitance effect, unveiling its direct connection with the free energy profile of HZO. • Demonstration of the origin of negative capacitance effect in multidomain M/HZO/M gate stack, attributing it to varying switching rates between free charge and polarization, primarily influenced by the negative capacitance region within HZO's free energy profile. • Prediction of the HZO's intrinsic switching speed for various experimentally extracted damping factorsof the HZO material, offering versatile control over device performance. • Investigation into the direct causes of the negative drain-induced barrier lowering effect and the negative differential resistance effect in Landau NCFETs. • Engineered Leaky-HZO to fix the leakage problem in NCFET design. • Development of a circuit-compatible hybrid compact model for leakage-aware negative capacitance circuit simulations, facilitating practical integration into negative capacitance electronics. This paper addresses the lack of understanding of the origin of negative capacitance (NC) effect in the hafnium zirconium oxide (HZO) ferroelectric (FE) gate stack and proposes a new circuit-compatible hybrid compact model for NC field-effect transistors (NCFETs). The model supports Landau and Preisach FE models, encompassing multiple FE domains, FE leakage, and FE damping. The proposed model is experimentally validated, and the intrinsic switching speed of HZO is predicted. It is revealed that the NC effect in HZO stems from a mismatch in free charge and polarization switching rates. Performance evaluation of the model reveals that HZO-NCFET achieves ∼1.18x and ∼9.17x higher amplification at low and high frequencies compared to its PZT-NCFET counterpart. Our study demonstrates the superior ON-current (2.74 mA/µm) of the Engineered Leaky-HZO NCFET, surpassing FinFET and Germanium-source L-shaped TFET by ∼7.89x and ∼4.81x, respectively. This study briefly examines the direct causes of the negative drain-induced barrier lowering effect and negative differential resistance effect in Landau NCFETs. Furthermore, we emphasize the crucial role of FE thickness in determining the magnitude of the NC effect, offering valuable insights for the design and optimization of NC-based devices and circuits. Analysis of the Miller effect in NCFET-based inverters demonstrates significant improvements owing to high ON-current and voltage amplification, making them suitable for high-speed NCFET-based circuitry. Landau and Preisach NCFET-based inverters exhibit (50.70%, 51.34%) lower overshoots and (28.45%, 28.61%) reduced propagation delay compared to the NC nanowire FET-based inverter. Moreover, NCFET-based 2:1 fork circuits significantly reduce (46.69%, 51.37%) critical clock skew compared to CMOS FET-based circuits, showcasing the potential of NCFET technology in addressing timing violations in random logic paths. Furthermore, the Landau and Preisach NCFET-based ring oscillators (ROs) achieve (39.97%, 49.38%) and (52.65%, 62.92%) higher oscillation frequencies (f OSC) compared to state-of-the-art graphene FET-RO and CMOS-RO, respectively. The 15-stage Leaky-HZO and Engineered Leaky-HZO NCFET-ROs outperform the double gate-FET-RO by ∼2.19x and ∼16.69x in terms of f OSC , highlighting their superior performance in frequency-domain metrics. These findings demonstrate the potential of NCFET-based digital and mixed-signal circuits for high-performance integrated circuit designs. [ABSTRACT FROM AUTHOR]

Recently, HfO2‐based ferroelectric thin films have attracted widespread interest in developing next‐generation nonvolatile memories. To form a metastable ferroelectric orthorhombic phase in HfO2, a post‐annealing process is typically necessary. However, the microscopic mechanism underlying the effect of annealing temperature on ferroelectric domain nucleation and growth is still obscure, despite its importance in optimizing the operation speed of HfO2‐based devices. In this study, the ferroelectric properties and polarization switching of Hf0.5Zr0.5O2 thin films annealed at different temperatures (550–700 °C) are systematically investigated. Evidently, the crystal structure, remnant polarization, and dielectric constant monotonically change with annealing temperature. However, microscopic piezoresponse force microscopy images as well as macroscopic switching current measurements reveal non‐monotonic changes in the polarization switching speed with annealing temperature. This intriguing behavior is ascribed to the difference in the ferroelectric‐domain nucleation process induced by the amount of oxygen vacancies in the Hf0.5Zr0.5O2 thin films annealed at different temperatures. This work demonstrates that controlling the defect concentration of ferroelectric HfO2 by tuning the post‐annealing process is critical for optimizing device performance, particularly polarization switching speed. [ABSTRACT FROM AUTHOR]

In this work, the electrocaloric effect (ECE) and electrocaloric strength (ΔT/E) were measured and thermal and dielectric studies were performed on Pb-modified BaTiO3 (BPT). The saturated hysteresis loops and normal ferroelectric behavior of the ferroelectric ceramics allow the utilization of the indirect method to estimate the electrocaloric properties. The electrocaloric measurements were performed under high (18 kV/cm) versus low (8 kV/cm) electric field conditions. These conditions were chosen to notice and then eliminate an artificial negative electrocaloric effect in the tested ceramics. At the same time, relatively high values of positive electrocaloric temperature change ΔT ( ~   2.19   K ) and electrocaloric strength ΔT/E ( ~ 0.27–0.11 K · cm/kV) were obtained. [ABSTRACT FROM AUTHOR]

Hybrid improper ferroelectricity can effectively avoid the intrinsic chemical incompatibility of electronic mechanism for multiferroics. Perovskite superlattices, as theoretically proposed hybrid improper ferroelectrics with simple structure and high technological compatibility, are conducive to device integration and miniaturization, but the experimental realization remains elusive. Here, we report a strain-driven oxygen octahedral distortion strategy for hybrid improper ferroelectricity in La2NiMnO6/La2CoMnO6 double-perovskite superlattices. The epitaxial growth mode with mixed crystalline orientations maintains a large strain transfer distance more than 90 nm in the superlattice films with lattice mismatch less than 1%. Such epitaxial strain permits sustainable long-range modulation of oxygen octahedral rotation and tilting, thereby inducing and regulating hybrid improper ferroelectricity. A robust room-temperature ferroelectricity with remnant polarization of ~ 0.16 μC cm−2 and piezoelectric coefficient of 2.0 pm V−1 is obtained, and the density functional theory calculations and Landau-Ginsburg-Devonshire theory reveal the constitutive correlations between ferroelectricity, octahedral distortions, and strain. This work addresses the gap in experimental studies of hybrid improper ferroelectricity for perovskite superlattices and provides a promising research platform and idea for designing and exploring hybrid improper ferroelectricity. Authors realize a tunable hybrid improper ferroelectricity in [La2NiMnO6/La2CoMnO6]n double perovskite superlattices at room temperature by a strain-driven oxygen octahedral distortion strategy. [ABSTRACT FROM AUTHOR]

Highlights: Ferroelectricity and domain dynamics of emerging ferroelectric AlScN films were discussed. The performance optimization of ferroelectric AlScN films grown by different deposition techniques was comprehensively analyzed. The challenges and perspectives regarding the commercial avenue of AlScN-based memories and in-memory computing applications were summarized. Ferroelectrics have great potential in the field of nonvolatile memory due to programmable polarization states by external electric field in nonvolatile manner. However, complementary metal oxide semiconductor compatibility and uniformity of ferroelectric performance after size scaling have always been two thorny issues hindering practical application of ferroelectric memory devices. The emerging ferroelectricity of wurtzite structure nitride offers opportunities to circumvent the dilemma. This review covers the mechanism of ferroelectricity and domain dynamics in ferroelectric AlScN films. The performance optimization of AlScN films grown by different techniques is summarized and their applications for memories and emerging in-memory computing are illustrated. Finally, the challenges and perspectives regarding the commercial avenue of ferroelectric AlScN are discussed. [ABSTRACT FROM AUTHOR]

Ferroelectricity, which has diverse important applications such as memory elements, capacitors, and sensors, was first discovered in a molecular compound, Rochelle salt, in 1920 by Valasek. Owing to their superiorities of lightweight, biocompatibility, structural tunability, mechanical flexibility, etc., the past decade has witnessed the renaissance of molecular ferroelectrics as promising complementary materials to commercial inorganic ferroelectrics. Thus, on the 100th anniversary of ferroelectricity, it is an opportune time to look into the future, specifically into how to push the boundaries of material design in molecular ferroelectric systems and finally overcome the hurdles to their commercialization. Herein, we present a comprehensive and accessible review of the appealing development of molecular ferroelectrics over the past 10 years, with an emphasis on their structural diversity, chemical design, exceptional properties, and potential applications. We believe that it will inspire intense, combined research efforts to enrich the family of high-performance molecular ferroelectrics and attract widespread interest from physicists and chemists to better understand the structure–function relationships governing improved applied functional device engineering. [ABSTRACT FROM AUTHOR]

The well‐developed high‐k technologies ease the integration complexity for HfO2‐based ferroelectric (FE) devices in the complementary metal‐oxide semiconductor processes. Sputtered HfxZr(1‐x)O2 (HZO) FEs have proven their thermal compatibility in back‐end‐of‐line (BEOL) integration processes with high remanent polarization (Pr) and a high cycling endurance. With the help of a tungsten oxide (WOx) bottom electrode, the sputtered HZO's FE properties are further advanced in this work. WOx is used to tune the oxygen content in the HZO film, providing an FE performance with a maximum 2Pr of 46 µC cm−2 and an endurance of 108 cycles. Based on this, sputtered HZO can compete with the atomic layer deposited HZO in the BEOL processes. In addition, WOx bottom electrodes enhance the FE capacitor behavior in a broad processing window, which relaxes the manufacturing restrictions. [ABSTRACT FROM AUTHOR]

We successfully developed a lanthanum (La)-doped Pb (Zr,Ti)O3 (PLZT) based ferroelectric capacitor (FC) using a new electrode material of bismuth (Bi) doped SrRuO3 (B-SRO) aiming at reduction of energy consumption of ferroelectric random access memory (FeRAM) by suppressing the leakage current of its FC. Our employed B-SRO layer is effective for suppressing the leakage current due to reducing atomic interdiffusions of Iridium and lead between IrOx top electrode (TE) and PLZT. Space charge limited conduction (SCLC) is dominant in the leakage current of the FC with B-SRO, while defect assisted conduction possibly includes in the leakage current of FC without B-SRO in addition with the SCLC. Switchable polarization, depending on the B-SRO thickness, has largest value for 1.0-1.5 nm thick B-SRO. Excellent imprint and switching (fatigue) endurances is proven on the FC with 1 nm thick BSRO. [ABSTRACT FROM AUTHOR]

The universal flexoelectric effect in solids provides a mechanical pathway for controlling electric polarization in ultrathin ferroelectrics, eliminating potential material breakdown from a giant electric field at the nanoscale. One challenge of this approach is arbitrary implementation, which is strongly hindered by one-way switching capability. Here, utilizing the innate flexibility of van der Waals materials, we demonstrate that ferroelectric polarization and domain structures can be mechanically, reversibly, and arbitrarily switched in two-dimensional CuInP2S6 via the nano-tip imprinting technique. The bidirectional flexoelectric control is attributed to the extended tip-induced deformation in two-dimensional systems with innate flexibility at the atomic scale. By employing an elastic substrate, artificial ferroelectric nanodomains with lateral sizes as small as ~80 nm are noninvasively generated in an area of 1 μm2, equal to a density of 31.4 Gbit/in2. Our results highlight the potential applications of van der Waals ferroelectrics in data storage and flexoelectronics. Flexoelectric effect may offer a voltage-free method to control the polarization in 2D ferroelectrics, but its widespread application remains challenging. Here, the authors report an approach to arbitrarily switch the ferroelectricity in 2D CuInP2S6. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) AMX2 compounds are a family of mixed ionic and electronic conductors (where A is a monovalent metal ion, M is a trivalent metal, and X is a chalcogen) that offer a fascinating platform to explore intrinsic coupled ionic-electronic properties. However, the synthesis of 2D AMX2 compounds remains challenging due to their multielement characteristics and various by-products. Here, we report a separated-precursor-supply chemical vapor deposition strategy to manipulate the chemical reactions and evaporation of precursors, facilitating the successful fabrication of 20 types of 2D AMX2 flakes. Notably, a 10.4 nm-thick AgCrS2 flake shows superionic behavior at room temperature, with an ionic conductivity of 192.8 mS/cm. Room temperature ferroelectricity and reconfigurable positive/negative photovoltaic currents have been observed in CuScS2 flakes. This study not only provides an effective approach for the synthesis of multielement 2D materials with unique properties, but also lays the foundation for the exploration of 2D AMX2 compounds in electronic, optoelectronic, and neuromorphic devices. 2D AMX2 compounds (where A is a monovalent metal ion, M is a trivalent metal, and X is a chalcogen) are a family of materials with coupled ionic-electronic properties. Here, the authors report a chemical vapor deposition strategy to fabricate 20 types of 2D AMX2 flakes, exhibiting superionic conductivity or room temperature ferroelectricity. [ABSTRACT FROM AUTHOR]

Multiferroic materials, which simultaneously exhibit ferroelectricity and magnetism, have attracted substantial attention due to their fascinating physical properties and potential technological applications. With the trends towards device miniaturization, there is an increasing demand for the persistence of multiferroicity in single-layer materials at elevated temperatures. Here, we report high-temperature multiferroicity in single-layer CuCrSe2, which hosts room-temperature ferroelectricity and 120 K ferromagnetism. Notably, the ferromagnetic coupling in single-layer CuCrSe2 is enhanced by the ferroelectricity-induced orbital shift of Cr atoms, which is distinct from both types I and II multiferroicity. These findings are supported by a combination of second-harmonic generation, piezo-response force microscopy, scanning transmission electron microscopy, magnetic, and Hall measurements. Our research provides not only an exemplary platform for delving into intrinsic magnetoelectric interactions at the single-layer limit but also sheds light on potential development of electronic and spintronic devices utilizing two-dimensional multiferroics. The authors observe multiferroicity in a single-layer non van der Waals material, CuCrSe2. The coexistence of room-temperature ferroelectricity and ferromagnetism up to 120 K is corroborated by a set of comprehensive experimental techniques. [ABSTRACT FROM AUTHOR]

Electro-optical effect-based liquid crystal devices have been extensively used in optical modulation techniques, in which the Kerr coefficient reflects the sensitivity of the liquid crystals and determines the strength of the device's operational electric field. The Peterlin–Stuart theory and the O'Konski model jointly indicate that a giant Kerr coefficient could be obtained in a material with both a large geometrical anisotropy and an intrinsic polarization, but such a material is not yet reported. Here we reveal a ferroelectric effect in a monolayer two-dimensional mineral vermiculite. A large geometrical anisotropy factor and a large inherent electric dipole together raise the record value of Kerr coefficient by an order of magnitude, till 3.0 × 10−4 m V−2. This finding enables an ultra-low operational electric field of 102–104 V m−1 and the fabrication of electro-optical devices with an inch-level electrode separation, which has not previously been practical. Because of its high ultraviolet stability (decay <1% under ultraviolet exposure for 1000 hours), large-scale production, and energy efficiency, prototypical displayable billboards have been fabricated for outdoor interactive scenes. This work provides new insights for both liquid crystal optics and two-dimensional ferroelectrics. [ABSTRACT FROM AUTHOR]

Out-of-plane polarized ferroelectric materials in a capacitive structure provide a key component for several technological applications. Furthermore, two-dimensional materials are expected to aid in the quest for both ultrathin and flexible electronics. Of the various two-dimensional ferroelectrics with out-of-plane polarization, CuInP2S6 is special in that the Cu atoms are highly mobile and it has been shown to possess both low- and high-polarization states. Using density-functional-theory calculations, we explore the stabilization of the ferroelectric state for several prototypical metal contacts (Gr, Ni, Cu, Au, and Ag). In all cases, we find that the ferroelectric state can be stabilized at fewer layers than in the freestanding case. For all of the considered conventional metal contacts, we also find the existence of a quasi-ferroelectric state that stabilizes a polar phase for thicknesses greater than two layers of CIPS. In the cases of Au and Ag, interfacial alignment and strain can be used to stabilize ferroelectricity at the bilayer limit. Furthermore, we find that the strength of the interaction between the contact and CuInP2S6 also leads to stabilization of the high-polarization state when ferroelectricity is stabilized. Lastly, energy-barrier calculations show that the system is still switchable in the presence of contact doping from the metal contacts. [ABSTRACT FROM AUTHOR]

Fundamental aspects of ferroelectric HfO 2 , a fluorite-type oxide, are not understood yet. This is evident by different theories regarding, e.g., the wake-up effect or the antiferroelectric-like behavior of HfO 2 manufactured with different doping or deposition techniques. Therefore, we focus on sputtered and undoped HfO 2 to gain deeper understanding of the ferroelectric properties of pure HfO 2. A temperature gradient on a 10 × 10 mm 2 substrate during rapid thermal annealing led to different ferroelectric device performances in terms of remnant polarization and the wake-up effect. The results from the electrical characterization are compared to observations by transmission electron microscopy, performed on pristine and trained samples in plan-view as well as in cross section. We observed that different temperature treatments caused effects at the interfaces of the TiN electrodes and also affected the microstructure and defect concentration of the HfO 2 itself. Devices from the hot corner showed wake-up free ferroelectricity with a remnant polarization below 10 μ C / cm 2 , whereas devices from the cold corner showed a strong wake-up effect with remnant polarization starting from 0 to above 20 μ C / cm 2 after 10 6 cycles. After observing a small structural transformation in trained devices, we attributed this strong wake-up effect to gradual ferroelastic switching of pristine [110] oriented grains with in-plane polarization to partially out-of-plane polarization, while the predominantly ⟨ 111 ⟩ oriented grains in the hot corner can suppress the wake-up effect. [ABSTRACT FROM AUTHOR]

Two-dimensional van der Waals ferroelectric semiconductors have attracted extensive research interest in both theoretical investigation and device applications due to their ferroelectricity and semiconducting nature. However, it is still not well understood how the ferroelectric phase is able to coexist with the semiconducting phase in this emerging material class. In this work, mm-scale continuous films of In2Se3 with a thickness of ∼3 nm were synthesized successfully by physical vapor deposition. Furthermore, we fabricated asymmetric ferroelectric semiconductor junctions (a-FSJs) from thick exfoliated and PVD-grown ultrathin In2Se3 films. A high read current density of ∼100 A/cm2 and a distinction ratio of over 102 at VRead = 0.5 V are achieved in devices fabricated by a 3 nm-thick In2Se3 film toward ultrahigh-density memory integration. Notably, the coercive voltage is constant, with In2Se3 film thickness decreasing from 200 to 3 nm. A qualitative model is proposed to elucidate the anomalous film-thickness-independent coercive voltage in this ultrathin a-FSJ, which can also be generalized to other emerging two-dimensional ferroelectric semiconductors. [ABSTRACT FROM AUTHOR]

The photovoltaic effect driven by ferroelectric polarization shows great application potential in photovoltaic devices. Two-dimensional (2D) Ruddlesden-Popper perovskite molecular ferroelectric materials, which combine polarization and low band gap properties, occupy a promising position in this field. However, literature reports mostly focus on single crystal blocks, and film devices are rarely reported. In this paper, 2D EA 4 Pb 3 Br 10 (EA=ethylammonium) molecular ferroelectrics are used as the absorption layers to prepare photovoltaic devices, and the photovoltaic performance of the devices is enhanced by polarization. Dense EA 4 Pb 3 Br 10 films are prepared by immediately adding antisolvent propylene glycol methyl ether acetate when the spin coating rate reaches the maximum. Surprisingly, the photovoltaic device exhibits significant photovoltaic effects under AM1.5 (100 mW/cm2) illumination with V OC ∼ 1.042 V and J SC ∼ 438.02 μA/cm2, which is much higher than that of ordinary inorganic ferroelectrics. In addition, the photovoltaic performance has been greatly improved by applying an external electric field, reaching to the maximum V OC ∼ 1.087 V and J SC ∼ 489.12 μA/cm2. This indicates the potential application prospects of 2D EA 4 Pb 3 Br 10 molecular ferroelectric films in photovoltaic devices. • The high-quality 2D molecular ferroelectric EA4Pb3Br10 films were prepared. • by the antisolvent method. • The photovoltaic device of EA 4 Pb 3 Br 10 can achieve photovoltaic effect regulation by polarization. • Transport layers can greatly improve the photovoltaic performance of molecular ferroelectric EA4Pb3Br10 films. • The photovoltaic performance of devices with p-i-n structure is much higher than that of ordinary inorganic ferroelectrics. [ABSTRACT FROM AUTHOR]

• This paper aims to establish an accurate physical basis for the transient negative capacitance (TNC) and the relationship between the TNC and organic ferroelectric's free energy profile. • The fundamental mechanism of TNC is caused by the switching rate difference between the free charge and polarization during the two stable state switching processes. • TNC appears immediately when the change in organic ferroelectric voltage (V OFE) per unit time is negative. • Unipolar pulsing does not produce the TNC effect. • The proposed organic ferroelectric capacitor may be employed as a gate stack of any standard transistor for designing beyond CMOS transistor technology. The physical mechanism of the negative capacitance (NC) effect in an organic ferroelectric (OFE) remains unknown. Therefore, this paper presents a series circuit of a resistor and an OFE capacitor (R-OFEC) based on experimentally validated Ginzburg-Landau-Khalatnikov (GLK) theory, electrostatics, and Kirchoff's circuit rule to understand the transient NC (TNC) mechanism in TCAD environment. We show that: (i) the fundamental mechanism of TNC in an R-OFEC is caused by switching rate difference between the free charge (Q OFE) and OFE polarization (P OFE) during the two stable state switching processes; (ii) Q OFE -P OFE difference is induced by the NC region of the OFE's double-well free energy landscape and its relationship with the change in voltage transient is demonstrated analytically; (iii) a bipolar pulsing is needed for TNC appearance; (iv) TNC appears immediately when the change in voltage across the OFEC per unit time is negative. Finally, the TNC effect caused by the Q OFE -P OFE difference is justified by its dependence on R. [ABSTRACT FROM AUTHOR]

Temperature-dependent dynamic ferroelectric hysteresis of semiconductor–relaxor ferroelectric (0–3) type composite {0.30(ZnO)–0.70[(Bi0.5Na0.5)0.94Ba0.06TiO3 (BNBTO)]} has been investigated using polarization–electric field (P–E) loops, current density–electric field (J–E) curves, and temperature-dependent dielectric permittivity. It is well known that the polarization reversal mechanism can be explained by the concept of ferroelectric domain switching kinetics, which depends strongly on the temperature. The present work ascribes the role of polar nanoregion induced thermal depolarization field on the temperature-dependent ferroelectric hysteresis loop along with polarization reversal mechanism. The present composite exhibits unique ferroelectric switching behavior above the thermal depolarization temperature (∼100 °C), which is observed in P–E and J–E loops. The depolarization field-induced pinched P–E loops of a BNBTO solid solution above Td (∼100 °C) have been significantly overcome by the incorporation of semiconductor (ZnO) particles, which extensively described the underlying mechanism in the present context. In addition, the temperature-dependent polarization reversal mechanism displays unique two-stage processes [low-T (<100 °C) and high-T (>100 °C)] for the minor loops (∼30 and 40 kV) and saturated loops (∼45 kV) as described by the electric field–temperature phase diagram. The present results may provide a distinct way to Bi0.5Na0.5TiO3-based solid solutions for high-temperature piezoelectric applications. [ABSTRACT FROM AUTHOR]

A WSe2 field effect transistor integrated with a lead zirconium titanate (PZT) pyroelectric device has been designed, fabricated, and tested and is described as the integrated pyroelectric device. The integrated device has been compared to a standalone pyroelectric device, which consists of PZT sandwiched between platinum electrodes. A pyroelectric coefficient of 1.755 × 10−4 C/m2K has been realized for our thin-film PZT (650 nm). The integrated device amplifies the output of the standalone device by over ten orders of magnitude as the current density calculated for the devices is 16 nA/mm2 and 1 nA/mm2, respectively. The interplay between the pyro- and ferro-induced polarization of the integrated device has been studied. From our observations, the ferroelectric gating controls directly the drain-source current output of the integrated device, showing anti-clockwise hysteresis behavior. The device shows promise for application in infrared sensing. [ABSTRACT FROM AUTHOR]

As a typical lead-free antiferroelectric material, silver niobate has attracted much attention in recent years due to its excellent performance in energy storage. In this work, based on a spherical aberration–corrected STEM-high angle annular dark field technique, the sites of each cation column of pure silver niobate and Ta-doped silver niobate were quantitatively obtained. Besides conventional antiferroelectric displacements along the ±[1−10]c directions, B-site ions were found to also deviate along ±[001]c directions and form many local off-centering nanoregions, which may induce weak ferroelectricity, just like polar nanoregions in relaxed ferroelectrics. Such results will further increase our understanding of silver niobate in the microscopic view and may help explain some unsolved questions. [ABSTRACT FROM AUTHOR]

Growing crystallographically incommensurate and dissimilar organic materials is fundamentally intriguing but challenging for the prominent cross-correlation phenomenon enabling unique magnetic, electronic, and optical functionalities. Here, we report the growth of molecular layered magnet-in-ferroelectric crystals, demonstrating photomanipulation of interfacial ferroic coupling. The heterocrystals exhibit striking photomagnetization and magnetoelectricity, resulting in photomultiferroic coupling and complete change of their color while inheriting ferroelectricity and magnetism from the parent phases. Under a light illumination, ferromagnetic resonance shifts of 910 Oe are observed in heterocrystals while showing a magnetization change of 0.015 emu/g. In addition, a noticeable magnetization change (8% of magnetization at a 1,000 Oe external field) in the vicinity of ferro-to-paraelectric transition is observed. The mechanistic electric-field-dependent studies suggest the photoinduced ferroelectric field effect responsible for the tailoring of photo-piezo-magnetism. The crystallographic analyses further evidence the lattice coupling of a magnet-in-ferroelectric heterocrystal system. [ABSTRACT FROM AUTHOR]

In this study, platinum (Pt) and tungsten (W), two materials with dissimilar coefficients of thermal expansion (CTE) and work functions (WF), are used as the top electrode (TE) and the bottom electrode (BE) in metal/ferroelectric/metal (MFM) structures to explore the ferroelectricity of hafnium zirconium oxide (HZO) with a thickness less than 10 nm. The electrical measurements indicate that a higher CTE mismatch between HZO and TE/BE is beneficial for enhancing the ferroelectric properties of nanoscale HZO thin films. The different WFs of TE and BE generate a built-in electric field in the HZO layer, leading to shifts in the hysteresis loops and the capacitance–voltage characteristics. The structural characterizations reveal that the preferred formation of the orthorhombic phase in HZO is dominated by the W BE. The device in which W is used as the TE and BE (the W/HZO/W MFM structure) presents the optimal ferroelectric performance of a high remanent polarization (2 P r = 55.2 μ C cm−2). The presence of tungsten oxide (WO x ) at the W/HZO interfaces, as revealed by high-resolution transmission microscopy, is also responsible for the enhancement of ferroelectric properties. This study demonstrates the significant effects of different CTEs and WFs of TE and BE on the properties of ferroelectric HZO thin films. [ABSTRACT FROM AUTHOR]

One of the negative effects of ferroelectric applications, particularly for electrocaloric effect (ECE) applications, is temperature hysteresis (ΔTHyst). Temperature hysteresis is the difference between the temperatures corresponding to the maximum dielectric permittivity in heating and cooling modes. The value of ΔTHyst is commensurate with the value of the ECE temperature change. The ECE is a phenomenon in which a material shows a reversible temperature change under an applied electric field. The aim of this work is to study the possibilities of temperature hysteresis reduction by varying the ceramic sintering temperature, changing the stoichiometry of BaxSr1-xTiO3 solid solutions, and changing the rate of the heating-cooling cycle. [ABSTRACT FROM AUTHOR]

The synthesis of DyFeO3 nanoparticles (NPs) by using the citrate precursor method is explored with multiferroic properties. The particle size, crystallinity and pure phase were assessed using transmission electron microscopy, selected area electron diffraction, Brunauer–Emmett–Teller and powder X-ray diffraction measurements, suggesting that the particles have a high surface area with an average grain size range of 34–64 nm. An ideal multiferroic property has been shown by a room-temperature ferroelectric loop and well-defined hysteresis with significant values of saturation and remanent magnetization with a coercive field. In addition, dye degradation of rhodamine B was also reported in DyFeO3 NPs, which revealed the maximum decolourization of dye in the presence of DyFeO3 NPs as a photocatalyst. The temperature and frequency-dependent electrical measurements viz. dielectric constant, dielectric loss, conductance and impedance of DyFeO3 NPs were investigated in the temperature variation of 50–450°C and also frequency range of 100 kHz to 2 MHz. [ABSTRACT FROM AUTHOR]

The preparation of 2D magnetoelectric (ME) nanomaterials with strong ME coupling is crucial for the fast reading and writing processes in the next generation of storage devices. Herein, 2D BaTiO3 (BTO)‐CoFe2O4 (CFO) ME nanocomposites are prepared through a substrate‐free coupling strategy using supercritical CO2. Such 2D BTO‐CFO with strong coupling is built through alternating in‐plane and out‐of‐plane epitaxy stacking, leading to remarkable mutual biaxial strain effects for spin‐lattice coupling. As a results, such strain effect significantly enhances the ferroelectricity of BTO and the ferrimagnetism of CFO, where an unexceptionally high ME coupling coefficient of (325.8 mV cm−1 Oe−1) is obtained for the BTO‐CFO nanocomposites. [ABSTRACT FROM AUTHOR]

2D ferroelectric materials are promising for designing low-dimensional memory devices. Here, we explore strain-tunable ferroelectric properties of group-IV monochalcogenides MX (M = Ge , Sn; X = S , Se) and their potential application in lateral field tunnel junction devices. We find that these monolayers have in-plane ferroelectricity, with their ferroelectric parameters being on par with other known 2D ferroelectric materials. Among SnSe, SnS, GeSe, and GeS, we find that GeS has the best ferroelectric parameters for device applications, which can be improved further by applying uniaxial tensile strain. We use the calculated ferroelectric properties of these materials to study the tunneling electroresistance (TER) of a 4 nm device based on a lateral ferroelectric tunnel junction. We find a substantial TER ratio of 10 3 – 10 5 in the devices based on these materials, which can be further improved up to a factor of 40 on the application of tensile strain. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel heterostructure comprised Au nanoparticles layer and BiFe 0.9375 Mn 0.0625 O 3 (BFMO) thin film was constructed in this paper. • The photocurrent density of BFMO photovoltaic devices was greatly enhanced by Localized Surface Plasmon Resonance effect (LSPR) from Au nanoparticles (Au-NPs). • A possible mechanism based on LSPR effect was proposed to demonstrate this enhanced photovoltaic effect in BFMO/Au-NPs heterostructures. Very recently, the ferroelectric photovoltaic effect of multiferroic BiFeO 3 (BFO) has attracted much attention because of its large photovoltage beyond the bandgap and unique photocurrent switchable characteristics. However, the poor short-circuit current density (J SC ∼ μA/cm2) of BFO leads to a low power conversion efficiency (PCE), which greatly hinders its application and development as photovoltaic or optoelectronic devices. In this paper, a novel heterostructure comprised Au nanoparticles layer and BiFe 0.9375 Mn 0.0625 O 3 (BFMO) thin film was constructed. The results and analysis showed that the photocurrent densities of all these heterostructures were greatly improved in comparison with that of pure BFMO film without Au layer. Especially, the maximum photocurrent density of 1.323 mA/cm2 was observed in the heterostructure of BFMO-Au-1 m, which is 50 times higher than that of pure BFMO film (26 μA/cm2). A possible mechanism was herein proposed that the Localized Surface Plasmon Resonance (LSPR) effect derived from Au nanoparticles might play a key role on the enhanced photocurrent densities of these heterostructures. Firstly, LSPR effect would effectively amplify the intensity of the incident light partially passing through BFMO film and then reentering the film through the diffuse reflection, which greatly enhance the light absorption of the film. Secondly, the locally strengthened electric field around Au nanoparticles greatly enhances the migration rate of surrounding electrons, and thus improves the separation efficiency of electron-hole pairs. Consequently, the photocurrent density of BFMO film was greatly enhanced by LSPR effect. [ABSTRACT FROM AUTHOR]

• Hf 0.5 Zr 0.5 O 2 (HZO)-stacked negative capacitance field-effect transistor (NCFET) for possible beyond-CMOS technology. • Impact of ferroelectric domain numbers on the performance of MFM stack and HZO-NCFET device-circuit co-design. • HZO-NCFET offers significant voltage amplification compared to conventional PZT-NCFET and P(VDF-TrFE)-NCFET. • This study predicts that HZO has a switching time approximately 20 times faster than traditional ferroelectric Pb(Nb 0.04 Zr 0.28 Ti 0.68)O 3. • The HZO-NCFET-RO outperforms standard CMOS-RO, showcasing its potential for advancing beyond-CMOS technologies and guiding NCFET design optimization. This paper explores the performance of Hf 0.5 Zr 0.5 O 2 (HZO)-stacked negative capacitance field-effect transistor (NCFET) for possible beyond complementary metal–oxide–semiconductor (CMOS) technology. For the first time, we investigate the impact of ferroelectric (FE) domain numbers on the negative capacitance (NC) effect, energy dissipation, NC effect voltage window, polarization ramping rate, voltage amplification (A NC), and oscillation frequency of a 5-stage HZO-NCFET inverter-based ring oscillator (HZO-NCFET-RO). The results show that HZO-NCFET is suitable for low-voltage and high-speed applications, providing a significant increase in A NC concerning the conventional PZT-NCFET and P(VDF-TrFE)-NCFET. Our study suggests that the HZO intrinsic NC effect time scale is tiny and limited by the FE switching. We show that the switching time of HZO is ∼20 times faster than the traditional FE [Pb(Nb 0.04 Zr 0.28 Ti 0.68)O 3 ]. Finally, the proposed 5-stage HZO-NCFET-RO offers superior performance with a 26% higher oscillation frequency and a 94.42% reduction in power dissipation compared to standard 5-stage CMOS inverter-based RO. These findings highlight the potential of HZO-stacked NCFET as an alternative device for the future beyond-CMOS technology. [ABSTRACT FROM AUTHOR]

• Elaborate photovoltaic heterostructures of BiFe 0.9375 Ti 0.0625 O 3 film and Au nanoparticles layers were designed and constructed. • These photovoltaic heterostructures exhibited the giant enhancement in the photocurrent density, maximum of which is 158 times higher than that of pure BiFeO 3 film. • An underlying mechanism for enhanced photovoltaic performance was proposed on the basis of local surface plasmon resonance effect. Recently, the ferroelectric photovoltaic effect of BiFeO 3 has attracted much attention due to its above-bandgap photovoltage and switchable photocurrent. However, the very low photocurrent density hinders its practical application. In this paper, elaborate photovoltaic heterostructures were constructed by BiFe 0.9375 Ti 0.0625 O 3 (BFTiO) film and Au nanoparticles layer. The results and analysis demonstrate that these heterostructures exhibit a huge enhancement in photocurrent density. A possible mechanism for the enhanced photocurrent density is proposed herein based on the Local Surface Plasmon Resonance (LSPR) effect. First, the incident light reaching the Au nanoparticles is amplified by the LSPR effect and reflected into the BFTiO film, thus improving its light absorption. Second, the photogenerated electrons in the vicinity of the BFTiO-Au interface are accelerated by the enhanced electromagnetic field caused by the LSPR effect, thereby promoting the separation efficiency of the photogenerated carriers. Consequently, the LSPR effect significantly increases the photocurrent density of the BFTiO film. Greatly Enhanced Photocurrent density of Bismuth Ferrite Photovoltaic Heterostructures via Localized Surface Plasmon Resonance. [Display omitted] [ABSTRACT FROM AUTHOR]

This review reports the latest trends in the ceramic composite matrix used for the magnetoelectric (ME) effect. In the last few years, ME composite has become the center of attraction for use in various electrically and magnetically coupled devices. The growth and use of electronic components everywhere have propulsively accelerated the exploration of self-powered electronic and sensor network devices. ME is a feasible technique for addressing difficulties of traditional batteries such as short life span and frequent recharge difficulties. Self-charging multiferroic components have been found for the constant working of mobile electronics that use multiferroic composites in response to magnetoelectric energy transformation. Researchers have rigorously studied the rigid and flexible magnetoelectric composites for their suitability in applications. This paper gives a comparative study between rigid and flexible magnetoelectric composites based on their properties and provides knowledge about the materials for such types of composites. It reviews the latest polymer-based ME materials as well as the related fabrication and polarization methods. The review finally encapsulates the applications in biomedicine, ranging from mechanical energy harvesters to sensors and actuators.

Multiferroic materials offer a promising avenue for manipulating digital information by leveraging the cross-coupling between ferroelectric and ferromagnetic orders. Despite the ferroelectricity has been uncovered by ion displacement or interlayer-sliding, one-unit-cell of multiferroic materials design and wafer-scale synthesis have yet to be realized. Here we develope an interface modulated strategy to grow 1-inch one-unit-cell of non-layered chromium sulfide with unidirectional orientation on industry-compatible c-plane sapphire. The interfacial interaction between chromium sulfide and substrate induces the intralayer-sliding of self-intercalated chromium atoms and breaks the space reversal symmetry. As a result, robust room-temperature ferroelectricity (retaining more than one month) emerges in one-unit-cell of chromium sulfide with ultrahigh remanent polarization. Besides, long-range ferromagnetic order is discovered with the Curie temperature approaching 200 K, almost two times higher than that of bulk counterpart. In parallel, the magnetoelectric coupling is certified and which makes 1-inch one-unit-cell of chromium sulfide the largest and thinnest multiferroics. 2D multiferroic materials have garnered broad interests due to their magnetoelectric properties and multifunctional applications. Here, the authors discover a multiferroic feature in interfacial modulation synthesized wafer-scale one-unit-cell Cr2S3. [ABSTRACT FROM AUTHOR]

Ferroelectric scandium-doped aluminum nitride (Al1-xScxN) is of considerable research interest because of its superior ferroelectricity. Studies indicate that Al1-xScxN may suffer from a high leakage current, which can hinder further thickness scaling and long-term reliability. In this work, we systematically investigate the origin of the leakage current in Al0.7Sc0.3N films via experiments and theoretical calculations. The results reveal that the leakage may originate from the nitrogen vacancies with positively charged states and fits well with the trap-assisted Poole-Frenkel (P-F) emission. Moreover, we examine the cycling behavior of ferroelectric Al0.7Sc0.3N-based FeRAM devices. We observe that the leakage current substantially increases when the device undergoes bipolar cycling with a pulse amplitude larger than the coercive electric field. Our analysis shows that the increased leakage current in bipolar cycling is caused by the monotonously reduced trap energy level by monitoring the direct current (DC) leakage under different temperatures and the P-F emission fitting. [ABSTRACT FROM AUTHOR]

We report the preparation and characterization of vanadium substituted four-layer Aurivillius compound Bi5Fe1.5V0.5Ti2O15 using spin coating method. Ferroelectricity in the prepared films are confirmed from the well saturated polarization vs electric field (P-E) loops having remnant polarization (2 Pr) around 12.94 µC/cm2 at room temperature. In addition, low temperature P-E measurements show a decrease in Pmax and 2 Pr, which is attributed to the stabilization of defect dipole complexes and domain pinning, as seen in bismuth-based ferroelectrics. Additionally, this decrease in polarization is accompanied by an increase in imprint, confirming the presence of defect dipoles manifested as internal fields. [ABSTRACT FROM AUTHOR]

Stacking two atomic layers together can induce interlayer (sliding) ferroelectricity that is absent in their naturally occurring crystal forms. With the flexibility of two-dimensional materials, more layers could be assembled to give rise to even richer polarization states. Here, we show that three-layer boron nitride can host ferro- and antiferroelectric domains in the same sample. When used as a tunneling junction, the polarization of these domains could be switched in a layer-by-layer procedure, producing multiple resistance states. Theoretical investigation reveals an important role played by the interaction between the trilayer boron nitride and graphene substrate. These findings reveal the great potential and unique properties of 2D sliding ferroelectric materials. Here, the authors use three-layer boron nitride to construct interfacial ferro- and antiferroelectric tunnel junctions and find that the polarization is flipped in a layer-by-layer way, resulting in multiresistance states. [ABSTRACT FROM AUTHOR]

The possibility to engineer (GeTe)m(Sb2Te3)n phase‐change materials to co‐host ferroelectricity is extremely attractive. The combination of these functionalities holds great technological impact, potentially enabling the design of novel multifunctional devices. Here an experimental and theoretical study of epitaxial (GeTe)m(Sb2Te3)n with GeTe‐rich composition is presented. These layered films feature a tunable distribution of (GeTe)m(Sb2Te3)1 blocks of different sizes. Breakthrough evidence of ferroelectric displacement in thick (GeTe)m(Sb2Te3)1 lamellae is provided. The density functional theory calculations suggest the formation of a tilted (GeTe)m slab sandwiched in GeTe‐rich blocks. That is, the net ferroelectric polarization is confined almost in‐plane, representing an unprecedented case between 2D and bulk ferroelectric materials. The ferroelectric behavior is confirmed by piezoresponse force microscopy and electroresistive measurements. The resilience of the quasi van der Waals character of the films, regardless of their composition, is also demonstrated. Hence, the material developed hereby gathers in a unique 2D platform the phase‐change and ferroelectric switching properties, paving the way for the conception of innovative device architectures. [ABSTRACT FROM AUTHOR]

This work systematically investigates the impact of a pre-annealed ZrO2 interfacial layer on the ferroelectric behavior of Hf0.5Zr0.5O2 (HZO) capacitors. The remanent polarization (2Pr) value of HZO capacitors, including configurations such as W/HZO/TiN/p+ Si, W/HZO/(pre-annealed) ZrO2/TiN/p+ Si, W/HZO/SiO2/TiN/p+ Si, and W/HZO/SiO2/p+ Si, exhibits significant variations. The W/HZO/(pre-annealed) ZrO2/TiN/p+ Si capacitor demonstrates superior ferroelectric performance, with a 2Pr value of ~32 µC/cm2. Furthermore, by optimizing the thickness combination of HZO and the pre-annealed ZrO2 interfacial layer, a capacitor with a 10 nm HZO and 2 nm ZrO2 achieves the largest 2Pr value. The pre-annealing process applied to ZrO2 is found to play a very important role in inducing the orthorhombic phase and thus enhancing ferroelectricity. This enhancement is attributed to the pre-annealed 2 nm ZrO2 interfacial layer acting as a structural guide for the subsequent HZO orthorhombic phase, thereby improving the ferroelectric performance of HZO capacitors. These findings provide a comprehensive explanation and experimental verification of the impact of pre-annealed ZrO2 on ferroelectric devices, offering novel insights for the optimization of ferroelectric properties. [ABSTRACT FROM AUTHOR]

Engineering piezo/ferroelectricity in two-dimensional materials holds significant implications for advancing the manufacture of state-of-the-art multifunctional materials. The inborn nonstoichiometric propensity of two-dimensional transition metal dichalcogenides provides a spiffy ready-available solution for breaking inversion centrosymmetry, thereby conducing to circumvent size effect challenges in conventional perovskite oxide ferroelectrics. Here, we show the extendable and ubiquitous piezo/ferroelectricity within nonstoichiometric two-dimensional transition metal dichalcogenides that are predominantly centrosymmetric during standard stoichiometric cases. The emerged piezo/ferroelectric traits are aroused from the sliding of van der Waals layers and displacement of interlayer metal atoms triggered by the Frankel defects of heterogeneous interlayer native metal atom intercalation. We demonstrate two-dimensional chromium selenides nanogenerator and iron tellurides ferroelectric multilevel memristors as two representative applications. This innovative approach to engineering piezo/ferroelectricity in ultrathin transition metal dichalcogenides may provide a potential avenue to consolidate piezo/ferroelectricity with featured two-dimensional materials to fabricate multifunctional materials and distinguished multiferroic. Nonstoichiometric transition metal dichalcogenides break symmetry, enabling piezo/ferroelectric effects. Here, the authors propose an approach to integrate these properties with diverse 2D materials, advancing multifunctional materials and devices. [ABSTRACT FROM AUTHOR]

Thermally triggered spatial symmetry breaking in traditional ferroelectrics has been extensively studied for manipulation of the ferroelectricity. However, photoinduced molecular orbital breaking, which is promising for optical control of ferroelectric polarization, has been rarely explored. Herein, for the first time, we synthesized a homochiral fulgide organic ferroelectric crystal (E)‐(R)‐3‐methyl‐3‐cyclohexylidene‐4‐(diphenylmethylene)dihydro‐2,5‐furandione (1), which exhibits both ferroelectricity and photoisomerization. Significantly, 1 shows a photoinduced reversible change in its molecular orbitals from the 3 π molecular orbitals in the open‐ring isomer to 2 π and 1 σ molecular orbitals in the closed‐ring isomer, which enables reversible ferroelectric domain switching by optical manipulation. To our knowledge, this is the first report revealing the manipulation of ferroelectric polarization in homochiral ferroelectric crystal by photoinduced breaking of molecular orbitals. This finding sheds light on the exploration of molecular orbital breaking in ferroelectrics for optical manipulation of ferroelectricity. [ABSTRACT FROM AUTHOR]

The superior size and power scaling potential of ferroelectric-gated Mott transistors makes them promising building blocks for developing energy-efficient memory and logic applications in the post-Moore's Law era. The close to metallic carrier density in the Mott channel, however, imposes the bottleneck for achieving substantial field effect modulation via a solid-state gate. Previous studies have focused on optimizing the thickness, charge mobility, and carrier density of single-layer correlated channels, which have only led to moderate resistance switching at room temperature. Here, we report a record high nonvolatile resistance switching ratio of 38,440% at 300 K in a prototype Mott transistor consisting of a ferroelectric PbZr0.2Ti0.8O3 gate and an RNiO3 (R: rare earth)/La0.67Sr0.33MnO3 composite channel. The ultrathin La0.67Sr0.33MnO3 buffer layer not only tailors the carrier density profile in RNiO3 through interfacial charge transfer, as corroborated by first-principles calculations, but also provides an extended screening layer that reduces the depolarization effect in the ferroelectric gate. Our study points to an effective material strategy for the functional design of complex oxide heterointerfaces that harnesses the competing roles of charge in field effect screening and ferroelectric depolarization effects. Ferroelectric transistors are promising building blocks for developing energy-efficient memory and logic applications. Here, the authors report a record high 300 K resistance on-off ratio achieved in ferroelectric-gated Mott transistors by exploiting a charge transfer layer to tailor the channel carrier density and mitigate the ferroelectric depolarization effect. [ABSTRACT FROM AUTHOR]

Using first-principles calculations, we predict that tunable ferroelectricity can be realized in oxide perovskites with the Grenier structure and ordered oxygen vacancies. Specifically, we show that R1/3A2/3FeO2.67 solids (where R is a rare-earth ion and A an alkaline-earth cation) exhibit polar phases, with a spontaneous polarization tunable by an appropriate choice of R and A. We find that larger cations combined with small R elements lead to a maximum in the polarization and to a minimum in the energy barriers required to switch the sign of the polarization. Ferroelectricity arises from cooperative distortions of octahedral and tetrahedral units, where a combination of rotational and sliding modes controls the emergence of polarization within three-dimensional connected layers. Our results indicate that polar Grenier phases of oxide perovskites are promising materials for microelectronic applications and, in general, for the study of phenomena emerging from breaking inversion symmetry in solids. [ABSTRACT FROM AUTHOR]

In recent years, multiferroic (MF) materials have attained remarkable attention because of their exceptional ability to demonstrate both ferroelectric (FE) and magnetic properties simultaneously which has lead to their applications in memory, sensors, and energy storage devices. Here, a simple synthesis approach is used to enhance the ferroelectricity and induce the multiferroicity in double transition metal carbide (DTM) MXene film. The successful synthesis is confirmed by X‐ray Diffraction (XRD), Raman Spectroscopy, and Scanning Electron Microscopy (SEM) analysis. In addition, the FE and magnetic hysteresis (MH) loops are conducted to observe the nature of synthesized materials. Furthermore, the magnetoelectric (ME) effect is also examined to explore its significance in data storage and ME signal generation devices. Thus, the findings reveal the first report on the co‐existence of FE and magnetic properties of DTM MXene for potential applications in nano‐electronic devices of future technology. [ABSTRACT FROM AUTHOR]

Tellurium oxides of the ATeO3 form typically do not crystallize in perovskite structures. Here, we show that perovskite-like ATeO3 (A = Ca, Sr, Ba) thin films can be grown on perovskite single-crystal substrates via epitaxial stabilization. These films are stable with high optical bandgaps, low dielectric losses, and a high electric breakdown strength. Hysteretic dielectric behavior found in SrTeO3 and BaTeO3 strongly suggests the presence of antiferroelectricity and ferroelectricity, respectively. These properties make perovskite tellurium oxides possibly appealing candidates for thin film coating or insulator materials in advanced microelectronics. Tellurium oxides constitute a largely unexplored class of materials that might show new and interesting functionalities in epitaxial thin-films. Our work encourages new work within this field. [ABSTRACT FROM AUTHOR]

Low-dimensional ferroelectrics have a great deal of potential for use in electronic memory devices. However, intrinsic one-dimensional (1D) ferroelectricity is very rare. Using first-principles calculations, we present the discovery of an inborn 1D Ta4OTe9I4 ferroelectric (FE) nanowire. Its distinctive geometry can cause spontaneous electric polarization along the z-axis and allow it to maintain a certain temperature and strain. In addition to its sizable spontaneous polarization and appropriate Curie temperature, the 1D Ta4OTe9I4 nanowire exhibits an energy barrier comparable to those of other ferroelectrics. With polarization reversal, the energy gap can be modulated in the range of 0.38–1.33 eV, corresponding to an apparent peak shift phenomenon in the optical response. We use this nanowire as an exemplary material for building a FE tunnel junction composed of Hf0.5Ta3.5OTe9I4/Ta4OTe9I4/W0.5Ta3.5OTe9I4 with a giant tunneling electroresistance ratio at zero and low bias. Our calculations suggest that this 1D intrinsically FE material obtained from van der Waals crystals can be used in miniaturized and advanced high-density information storage. [ABSTRACT FROM AUTHOR]