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As a multiferroic material with substantial magnetoelectric coupling, gallium ferrite (GaFeO3, GFO) has been intensively studied in recent years. Cobalt ferrite (CoFe2O4, CFO) nano-hollowsphere (NHS), on the other hand, is found to be an efficient material for electromagnetic (EM) wave absorption. In this work, a composite consisting of magnetostrictive CFO NHS coated with GFO nanoparticles [(1−x)CoFe2O4 – xGaFeO3, for x = 0.0, 0.9, 0.7, 0.5, 0.3, and 1.0] is prepared as an effective strategy to develop highly efficient microwave material. The EM wave absorption properties of the samples are thoroughly investigated across a widely used frequency range of 1–20 GHz. Remarkable performance of the x = 0.7 composite is evident by its effective bandwidth of approximately 3 GHz and a minimum reflection loss of approximately −63.26 dB. Moreover, the excellent impedance matching, with |Zin/Z0| ≅ 1.00, observed in the aforementioned composite, satisfies well with the required characteristics for a superior microwave absorber. Therefore, a core–shell nanostructure consisting of CFO NHS as core and GFO with optimized shell thickness can be used successfully in microwave devices. [ABSTRACT FROM AUTHOR]

Magnetoelectric (ME) effects in a ferromagnetic and piezoelectric composite are the changes in the polarization caused by a magnetic field or the changes in the magnetization caused by an electric field. These effects are aided by the mechanical deformation in the ferroic phases caused by the combination of magnetostriction and piezoelectricity. Interest in ME effects is due to a variety of physical phenomena they exhibit, as well as their potential applications in the creation of highly sensitive magnetic field sensors and other electronic devices. Linear ME effects in structures with layers of different ferroic materials have been studied extensively. However, nonlinear ME effects, which are caused by the nonlinearity of the magnetic, dielectric, and acoustic properties of ferromagnets and piezoelectrics, are less well understood. The purpose of this review is to summarize the current state of knowledge on nonlinear ME (NLME) effects in composite heterostructures and to discuss their potential applications. The review begins by discussing the characteristics of materials that are conductive to the occurrence of NLME effects and ferromagnetic-piezoelectric materials that are most commonly used to study such effects. The review then provides details on theoretical approaches to the description of NLME effects in heterostructures and experimental methods for studying these effects. Finally, the review presents a chronological overview of the experimentally observed NLME effects in composite structures excited by low-frequency and pulsed magnetic or electric fields. The review concludes with a discussion on the potential applications of NLME effects for highly sensitive magnetic field sensors. [ABSTRACT FROM AUTHOR]

Using a molecular beam epitaxy technique, we experimentally demonstrate a multiferroic heterostructure consisting of metastable ferromagnetic Co 3 Mn on piezoelectric Pb(Mg 1 / 3 Nb 2 / 3 )O 3 –PbTiO 3 (PMN-PT). Inserting a 2-nm-thick Fe layer between Co 3 Mn and PMN-PT(001) allows the formation of bcc Co 3 Mn layers even at an extremely low growth temperature of ∼ 80 ° C. Upon increasing this temperature to 200 ° C, a bcc Co 3 Mn/Fe/PMN-PT(001) multiferroic heterostructure with a relatively large saturation magnetization of ∼ 1680 kA/m and an atomically flat interface is obtained, resulting in an obvious converse magnetoelectric (CME) effect. The large CME effect originates mainly from the strain-induced modulation of the magnetic anisotropy energy, supported by the first-principles calculations. [ABSTRACT FROM AUTHOR]

We report an unexplored type-II multiferroic order in NiMn 2 O 4 , exhibiting strong linear magnetoelectric coupling above liquid-nitrogen (LN) temperature. The compound becomes ferroelectric at ∼ 100 K, coinciding with ferrimagnetic ordering, with a polarization value of ∼ 535 μ C/m 2 for a poling field of 5 kV/cm. At LN temperature, the polarization value increases linearly (∼ 21 %) with a magnetic field up to 30 kOe. Rietveld refinement of neutron diffraction patterns reveals a ferrimagnetic model with antiparallel moments at tetrahedral and octahedral sites, as well as a canting of octahedral moment persisting up to ∼ 100 K. Low-temperature synchrotron diffraction confirms a step-like oxygen displacement during multiferroic ordering, suggesting that the Dzyaloshinskii–Moriya interaction polarizes the intervening oxygen atoms through magnetostriction, providing a microscopic mechanism for spontaneous electric polarization in this linear magnetoelectric multiferroic compound. [ABSTRACT FROM AUTHOR]

We report an unexplored type-II multiferroic order in NiMn 2 O 4 , exhibiting strong linear magnetoelectric coupling above liquid-nitrogen (LN) temperature. The compound becomes ferroelectric at ∼ 100 K, coinciding with ferrimagnetic ordering, with a polarization value of ∼ 535 μ C/m 2 for a poling field of 5 kV/cm. At LN temperature, the polarization value increases linearly (∼ 21 %) with a magnetic field up to 30 kOe. Rietveld refinement of neutron diffraction patterns reveals a ferrimagnetic model with antiparallel moments at tetrahedral and octahedral sites, as well as a canting of octahedral moment persisting up to ∼ 100 K. Low-temperature synchrotron diffraction confirms a step-like oxygen displacement during multiferroic ordering, suggesting that the Dzyaloshinskii–Moriya interaction polarizes the intervening oxygen atoms through magnetostriction, providing a microscopic mechanism for spontaneous electric polarization in this linear magnetoelectric multiferroic compound. [ABSTRACT FROM AUTHOR]

Multiferroic composites of sol-gel synthesized Sodium Bismuth Titanate (Na 0.5 Bi 0.5 TiO 3) and Co–Ti substituted Barium Hexaferrite (BaFe 12-2x Co x Ti x O 19 ; x = 0.0, 0.5, 1.0, 1.5 and 2.0) in the ratio 3:1 was synthesized through ceramic route. Successful formation of R3c rhombohedral and P63 / mmc hexagonal phases corresponding to Na 0.5 Bi 0.5 TiO 3 and BaFe 12-2x Co x Ti x O 19 respectively was confirmed from the XRD and Rietveld refinement pattern. The frequency and temperature dependence of dielectric constant and loss of the composite systems exhibited typical dispersion behaviour which could be understood using the Maxwell-Wagner model. Substituted samples showed enhanced dielectric behaviour where dielectric constant was observed to increase while loss tangent decreased. Using the Universal Jonscher's Power law (JPL), conductivition mechanisms of the composite systems were studied from the ac conductivity behaviour which revealed that the x = 0.0 sample followed Non-overlapping Small Polaron Tunnelling (NSPT) model while the remaining samples followed the Correlated Barrier Hopping (CBH) model. The complex impedance and Nyquist plot analysis showed the enhancement of resistive property in the x ≠ 0 systems. Magnetic hysteresis loop measurements were conducted, and the associated parameters were determined with the assistance of the Law of Approach to Saturation (LAS). Favourable reduction in the magnetic anisotropy was observed indicating the disturbance of magnetic spin structure in the hexaferrite phase. The P-E loops established the novel room temperature multiferroic nature of the composite systems. Significant magnetoelectric coupling was detected at room temperature in all samples, with the x = 0.5 sample exhibiting the highest value of approximately 59.81 mV/cmOe. These desirable properties suggest that the composites may find future device applications as in magnetically tunable energy harvesting devices and self-powered magnetoelectric sensors in the future. [ABSTRACT FROM AUTHOR]

Orthorhombic perovskite GdFeO3 nanostructures are promising materials with multiferroic properties. In this study, a new low‐temperature plasma‐assisted approach is developed via dual anodic dissolution of solid metallic precursors for the preparation of perovskite GdFeO3 nanoparticles (NPs) that can be collected both as colloids as well as deposited as a thin film on a substrate. Two solid metallic foils of Gd and Fe are used as precursors, adding to the simplicity and sustainability of the method. The formation of the orthorhombic perovskite GdFeO3 phase is supported by high‐resolution transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, and Raman measurements, while a uniform elemental distribution of Gd, Fe, and O is confirmed by energy dispersive X‐ray spectroscopy, proving the successful preparation of ternary compound NPs. The magnetic properties of the NPs show zero remnant magnetization typical of antiferromagnetic materials, and saturation at high fields that can be caused by spin interaction between Gd and Fe magnetic sublattices. The formation mechanism of ternary compound NPs in this novel plasma‐assisted method is also discussed. This method is also modified to demonstrate the direct one‐step deposition of thin films, opening up opportunities for their future applications in the fabrication of magnetic memory devices and gas sensors. [ABSTRACT FROM AUTHOR]

Herein, the multiferroic perovskite Er0.9La0.1Cr0.8Fe0.2O3 was synthesized using the sol–gel method, and its structure and multiferroic properties were investigated. The magnetic order of Er0.9La0.1Cr0.8Fe0.2O3 was analyzed through magnetic entropy change curves. Furthermore, a four‐sublattice molecular field model was constructed to study the spin reorientation phenomena and explain the differences between various spin redirections through magnetic order correction. This work will provide a new perspective for studying the properties of type II multiferroic materials. [ABSTRACT FROM AUTHOR]

The ever-growing need for advancement in data storage technology demands materials that can be controlled by as many degrees as possible. In this regard, multiferroic materials that show response both in electric and magnetic dimensions are of great interest especially when being investigated in two-dimensional materials that have their potential applications. In this study, we have incorporated Lanthanum (La) doped Bismuth Ferrite (BLFO), and La and Selenium (Se) co-doped BFO (BLFSO) with two-dimensional layered titanium carbide (Ti 3 C 2 T x) from the class of MXene as hybrid composites. The structural, optical and morphological investigation validated the successful etching of MXene from MAX, successful hybrid formation with conserved crystal structure and new phases of titanium dioxide (TiO 2) detected when the samples underwent heat treatment. This heat treatment was performed in order to enhance the multiferroic properties owing to the presence of TiO 2. Our results showed that the heated BLFSO-embedded Ti 3 C 2 T x hybrid composite showed maximum remnant polarization and higher dielectric response when measured with respect to the varying electric field and at different frequencies. The prepared samples also exhibited tunable polarization response at an applied static magnetic field, unveiling their magnetoelectric properties. [ABSTRACT FROM AUTHOR]

A hydroelectric cell has been coined as an accomplished device keeping the ability to produce current just by adsorbing a few microliters of water. These cells are the new source of generating green energy which involves no evolution of toxic gases like NO2, SO2, CO, etc. Our current research focuses on studying how to increase the maximum output current (I) in the pure cobalt ferrites by doping with rare-earth ion, yttrium. The yttrium-doped cobalt ferrites with composition (CoYxFe2−xO4, x = 0.00, 0.10, and 0.20) have been prepared using a modified sol–gel citrate method. X-ray diffractogram (XRD) confirmed the formation of cubic crystal structures with crystallite size less than 30 nm. Energy dispersive x-ray (EDX) patterns confirmed the presence of elements (Y, Co, Fe, O) in the prepared compositions. The ionic diffusion mechanism confirmed the dissociation of water molecules by the cations present on the surface of the material at room temperature. Vibrating sample magnetometer (VSM) analysis revealed the increase in coercivity values from 948.81 Oe to 2580.09 Oe with the increase in the concentration of yttrium ions in the cobalt ferrite (CFO) lattice. The V–I polarization curves measured the maximum output current and voltage as around 8.6 mA and 1.1 V, respectively, for the 20% yttrium-doped CFO hydroelectric cells (area = 4 cm2). [ABSTRACT FROM AUTHOR]

This study aims to enhance the multiferroic properties of bismuth ferrite (BFO) by investigating the effects of substitution with erbium (Er) on the material's structural, optical, and magnetic characteristics. Er-substituted bismuth ferrite (Bi1−xErxFeO3) (x = 0, 0.04, 0.08, 0.12, 0.16) nanoparticles (NPs) were synthesized via the very cost-effective Pechini modified sol–gel method followed by auto-combustion. X-ray diffraction (XRD) patterns confirmed the crystallinity, structure, and purity of the phase, revealing the formation of single-phase materials. The bond structure of the prepared samples was examined using Fourier transform infrared (FTIR) spectroscopy, confirming the significant stretching and bending of bonds of perovskites. Electron paramagnetic resonance (EPR) findings suggested a broadening of the signal as well as a shift of the center of resonance to lower fields. The experimental findings revealed that Er doping has a significant effect on the magnetic ordering and saturation magnetization of BiFeO3. In addition, UV–Vis spectroscopy demonstrated that the energy bandgap in the prepared samples varies from 2.13 eV to 1.71 eV. This research contributes to an understanding of the enhanced structural, magnetic, and optical properties of Er-substituted BFO nanoparticles, which is useful for designing and developing multiferroic materials with enhanced magnetic functionality for next-generation magnetoelectric devices, optoelectronic devices, and photocatalysts. [ABSTRACT FROM AUTHOR]

Multiferroics with compositions BiFeO3, Bi0.90Ho0.10FeO3 and BiFe0.90Ho0.10O3 have been successfully prepared by solid-state reaction method. The structural analysis of Ho-substituted BiFeO3 affirms that the compounds are crystallized under rhombohedral perovskite structure with space group $R\overline 3 c$R3¯c along with non-perovskite Bi2Fe4O9 phase. Cuboidal-shaped grains are observed in the micrographs of the Ho-substituted BiFeO3 sample with Ho at the Fe site. The changes in electrical and dielectric parameters with Ho substitution at the A-/B-site of BiFeO3 have a strong co-relation to its structural density, phase transformation and presence of Bi2Fe4O9 phase. These parameters are strongly dependent on the frequency, and its high values are obtained at low frequency because of the space charge polarization effect. The smaller values of impedance phase angles of BiFeO3, Bi0.90Ho0.10FeO3 and BiFe0.90Ho0.10O3 compounds compared to the anticipated $90^\circ$90∘ for an ideal capacitor show that these BFO-based compounds possess non-ideal capacitive/pseudocapacitive behavior. [ABSTRACT FROM AUTHOR]

Magnetic field is used to explore the mechanism of ferroelectric-dynamic coupling in the photovoltaic effect, where the spin–orbit coupling gives rise to and the expansion of relaxation times for electron–hole pair recombination. Thus, phonons with spin-1 and spin-1/2 electrons can be regulated by the magnetic field, which contributes to ferroelectric photovoltaics. The ballistic photocurrents originate from the asymmetric scattering of spin carriers by multiferroics, where significant photocurrent and magneto-spectrum responses are observed in Bi 6- x Pr x Ti 3 Fe 2 O 18 (x = 0.0, 0.3, 0.6, 0.9, 1.2) multiferroics. The magnetic field-dependent photoelectric spectra and J - V curves under illumination have validated the prolonged relaxation lifetime and improvement of density of electron–hole pairs. The evolution of multiferroic orders and magnetic field-dependent photovoltaic response spectra correlate to the ratio of phase B 2 cb / F 2 mm. These results reveal the distinct advantages of multiferroics, which are expected to be an ideal platform to improve efficiency and further clarify the ferroelectric photovoltaic mechanism. • The observation of ballistic photocurrents in multiferroics. • The expansion of relaxation lifetime and generation of electron–hole pairs. • The perspective of ferroelectric photovoltaic mechanism from spatial-temporal symmetry broken. [ABSTRACT FROM AUTHOR]

Two-dimensional materials possessing intrinsic multiferroic properties have long been sought to harness the magnetoelectric coupling in nanoelectronic devices. Here, we report the achievement of robust type I multiferroic order in single-layer chromium trihalides by decorating transition metal atoms. The out-of-plane ferroelectric polarization exhibits strong atomic selectivity, where 12 of 84 single-layer transition metal-based multiferroic materials possess out-of-plane ferroelectric or antiferroelectric polarization. Group theory reveals that this phenomenon is strongly dependent on p–d coupling and crystal field splitting. Cu decoration enhances the intrinsic ferromagnetism of trihalides and increases the ferromagnetic transition temperature. Moreover, both ferroelectric and antiferroelectric phases are obtained, providing opportunities for electrical control of magnetism and energy storage and conversion applications. Furthermore, the transport properties of Cu(CrBr3)2 devices are calculated based on the non-equilibrium Green's function, and the results demonstrate outstanding spin-filtering properties and a low-bias negative differential resistance (NDR) effect for low power consumption. [ABSTRACT FROM AUTHOR]

Herein, from first‐principles calculations, the phase diagram of the low‐spin (LS) state of BiCoO3 is scrutinized. The phonon‐dispersion curves of the cubic phase are analyzed to identify all the possible unstable modes and assessed the energy gain of the resulted distorted phases. In the findings, the presence of similar phases is revealed in both LS and high‐spin (HS) states, including ferroelectric and octahedra rotations distortions. However, the relative energy ordering of these phases differs significantly between the two states. Notably, the energy gain from mode condensation is considerably less pronounced in the LS case compared to HS state. Furthermore, it is identified that the common Pnma phase is the ground state of the LS state of BiCoC3, closely followed by the Imma octahedra rotation phase and the R3c ferroelectric phase, hence, different from the P4mm ferroelectric ground state of the HS state. [ABSTRACT FROM AUTHOR]

Increasing demand for functional materials crucial for advancing new technologies has motivated significant scientific and industrial research efforts. High-entropy materials (HEMs), with tunable properties, are gaining attention for their use in high-frequency transformers, microwave devices, multiferroics, and high-density magnetic memory components. The initial exploration of HEMs started with high-entropy alloys (HASs), such as CrMnFeCoNi, CuCoNiCrAlxFe, and AlCoCrTiZn and paved the way for a multitude of HEM variations, including oxides, oxyfluorides, borides, carbides, nitrides, sulfides, and phosphides. In this study, we fabricated the high-entropy oxide (HEO) compound B i 0.5 L a 0.1 I n 0.1 Y 0.1 N d 0.1 G d 0.1 F e O 3 through the solid-state synthesis method. Magnetic measurements at 300 K show ferromagnetic behavior with significant coercivity. At the same time, this novel composition exhibits excellent dielectric properties and shows potential for electronic applications demonstrating that a high-entropy approach can expand the compositional range of rare earth multiferroics and improve the multifunctional properties in multiferroic applications. [ABSTRACT FROM AUTHOR]

Herein, from first‐principles calculations, the phase diagram of the low‐spin (LS) state of BiCoO3 is scrutinized. The phonon‐dispersion curves of the cubic phase are analyzed to identify all the possible unstable modes and assessed the energy gain of the resulted distorted phases. In the findings, the presence of similar phases is revealed in both LS and high‐spin (HS) states, including ferroelectric and octahedra rotations distortions. However, the relative energy ordering of these phases differs significantly between the two states. Notably, the energy gain from mode condensation is considerably less pronounced in the LS case compared to HS state. Furthermore, it is identified that the common Pnma phase is the ground state of the LS state of BiCoC3, closely followed by the Imma octahedra rotation phase and the R3c ferroelectric phase, hence, different from the P4mm ferroelectric ground state of the HS state. [ABSTRACT FROM AUTHOR]

Multiferroic materials are an exceptional class of magnetic materials where long-range magnetic and ferroelectric orders coexist, thus provoking the researchers' interest from both basic and practical points of view. The magnetoelectric multiferroics are materials that combine coupled electric and magnetic dipoles. Recently, research has focused on the occurrence of the magnetoelectric effect in some hexagonal ferrite types and the possibility of their use as single-phase multiferroic and magnetoelectric materials. For many years, various hexaferrites have been intensively studied as materials for permanent magnets, high-density recording media, microwave devices, biomedical applications, etc. The magnetic structure and especially the specific magnetic spin arrangement under certain conditions proved to be key factors for the realization of magneto-electric phases in hexaferrites. Here some recent advances in our studies of the magnetic phase transitions in the Y-type hexaferrites are overviewed. In particular, the influence of the replacement of non-magnetic Me2+ cations with magnetic cations and of magnetic Fe3+ cations with non-magnetic ones on the magnetic properties and occurring magnetic phase transitions in Y-type hexaferrites are exemplified with Ba0.5Sr1.5Zn2Fe12O22. [ABSTRACT FROM AUTHOR]

The search for new materials and compositions, in which the phenomena of ferrimagnetism and ferroelectricity are closely coupled, is of great technological interest. In the present study, composite systems of (BaTiO 3) (100- x)% /(CoNb 0 · 02 Fe 1 · 98 O 4) x % where x = 0, 2, 5, 10, 20, and 100% were produced. Initially, BaTiO 3 (BTO) was made by sol-gel combustion approach and CoFe 1 · 98 Nb 0 · 02 O 4 (CoFeNbO) was made by hydrothermal method. Both compounds were then combined via solid-state reaction route to form the composite systems. According to X-ray diffraction, the pristine BTO and CoNbFeO display tetragonal and cubic structures, respectively, and all composite systems consisted of the cubic phase for BTO and spinel phase for CoNbFeO. Scanning electron microscopy showed a decrease in grain size (from 0.552 μm to 0.194 μm) and porosity (from 18.65% to 4.57%) as the CoNbFeO content increases from x = 0 to x = 20%, respectively. The influence of magnetic CoNbFeO content on the magnetic, ferroelectric, magnetoelectric coefficient, electric, and dielectric properties of composite systems has been investigated. The ferromagnetic and ferroelectric natures of diverse composite systems are reflected via the registered M-H and P-E loops at ambient temperature. A steady increase in magnetic parameters such as saturation magnetization and remanent magnetization is observed as the spinel ferrite CoNbFeO content increases. Similarly, the values of the electric coercivity increased from 1.65 kV/cm for x = 0% to 3.99 kV/cm for x = 20%. The frequency-dependent dielectric and electrical measurements were also investigated at various temperatures. By raising the measurement temperature, the dielectric polarization was found to increase for composite systems with x > 2%. Interestingly, the tangent loss was reduced for different composite systems in comparison to pristine BTO and CoNbFeO materials. The lowest tangent loss values were noticed for x = 5% composite system. All composite systems revealed good magnetoelectric coupling with coupling coefficient magnitudes up to a maximum value of ∼22.5 mV/cm.Oe, indicating that they can be potential candidates for use in advanced multifunctional electric devices. [ABSTRACT FROM AUTHOR]

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Relativistic ratcheting of Dirac fermions on the surface of topological insulator Bi 2 Se 3 attached to a spiral multiferroic oxide is investigated. We find that the Dirac fermions on the surface of topological insulator Bi 2 Se 3 exhibit pronounced Brownian motion, tuned by the strength of exchange field established by the interaction of spin degrees of Dirac fermions and multiferroic oxide. The surface Dirac fermions show ratchet effect as a net current under the influence of orthogonal, commensurate ac drives in the presence of a symmetric periodic potential set by the exchange field. [ABSTRACT FROM AUTHOR]

There is a growing interest in BiFeO3-based alloys because of the possibility it offers for developing high-temperature high-performance piezoelectric materials and for their interesting multiferroic properties. Often such ceramics are synthesized with additives either to reduce/suppress leakage current that the system inherits from the parent compound BiFeO3 or to promote sintering via formation of the liquid phase. We demonstrate here the propensity for stabilizing ferromagnetism in the ferroelectric solid solution BiFeO3–PbTiO3 (BF–PT) when synthesized with additive MnO2. Detailed investigation revealed that the ferromagnetic property of the ceramic is extrinsic and caused by the additive enabled precipitation of trace amount of the ferrimagnetic Pb-hexaferrite phase, not easily detected in conventional x-ray diffraction measurements. We also show that the ferromagnetic property is induced in Co-modified BF–PT. However, in this case, the additive stabilizes the CoFe2O4 spinel ferrite phase. While our findings offer a strategy to develop particulate magnetoelectric multiferroic composites using additive assisted precipitation of the ferrimagnetic phase(s) in BiFeO3-based ferroelectric alloys, it also helps in better understanding of the electromechanical response in BFO-based alloys. [ABSTRACT FROM AUTHOR]

Multiferroic materials have important research significance in the fields of magnetic random-access memory, ferroelectric random-access memory, resistive random-access memory, and neuromorphic computing devices due to their excellent and diverse physical properties. In this work, a solution of Bi2FeMnO6 was prepared using a solution-based method, and an Au/Bi2FeMnO6/TiO2 heterostructure device was fabricated on a Si substrate. X-ray diffraction and transmission electron microscopy data indicate that the Bi2FeMnO6 films have hexagonal R3c symmetry structures. The Bi2FeMnO6 film exhibits ferroelectricity with a fine remanent polarization. In addition, the Bi2FeMnO6-based devices have excellent switching ratios of 6.37 × 105. A larger switching ratio can provide a multi-resistance state for the device, which is beneficial for the simulation of synapses. Hence, it effectively emulates excitatory postsynaptic currents, paired-pulse facilitation, and long-term plasticity of synapses and achieves recognition accuracy of 95% in neuromorphic computing. We report a promising material for the development of various nonvolatile memories and neuromorphic synaptic devices. [ABSTRACT FROM AUTHOR]

This paper presents a novel approach for the fabrication of magnetoelectric composites aimed at enhancing cross-coupling between electrical and magnetic phases for potential applications in intelligent sensors and electronic components. Unlike previous methodologies known for their complexity and expense, our method offers a simple and cost-effective assembly process conducted at room temperature, preserving the original properties of the components and avoiding undesired phases. The composites, composed of PZT fibers, cobalt (CoFe2O4), and a polymeric resin, demonstrate the uniform distribution of PZT-5A fibers within the cobalt matrix, as demonstrated by scanning electron microscopy. Detailed morphological analyses reveal the interface characteristics crucial for determining overall performance. Dielectric measurements indicate stable behaviors, particularly when PZT-5A fibers are properly poled, showcasing potential applications in sensors or medical devices. Furthermore, H-dependence studies illustrate strong magnetoelectric interactions, suggesting promising avenues for enhancing coupling efficiency. Overall, this study lays the basic work for future optimization of composite composition and exploration of its long-term stability, offering valuable insights into the potential applications of magnetoelectric composites in various technological domains. [ABSTRACT FROM AUTHOR]

Controlled modulation of electronic and magnetic properties in stimuli‐responsive materials provides valuable insights for the design of magnetoelectric or multiferroic devices. This paper demonstrates the modulation of electrical and magnetic properties of a semiconductive, paramagnetic metal−organic framework (MOF) Cu3(C6O6)2 with small gaseous molecules, NH3, H2S, and NO. This study merges chemiresistive and magnetic tests to reveal that the MOF undergoes simultaneous changes in electrical conductance and magnetization that are uniquely modulated by each gas. The features of response, including direction, magnitude, and kinetics, are modulated by the physicochemical properties of the gaseous molecules. This study advances the design of multifunctional materials capable of undergoing simultaneous changes in electrical and magnetic properties in response to chemical stimuli. [ABSTRACT FROM AUTHOR]

The multiferroic magnetoelectric 2–2 laminated composite systems with BaTiO3 and NiFe2O4 as the ferroelectric and ferrimagnetic phases were successfully fabricated by co-firing technique. For this phase, pure BaTiO3 and NiFe2O4 were successfully synthesized by sol–gel and polyol method, respectively. The structural, microstructural, multiferroic and magnetoelectric coupling properties of phase pure and co-fired systems were investigated using X-ray diffraction, HR-TEM, SEM–EDX, P–E Loop, VSM and magnetoelectric coupling analysis. The multiferroic and magnetoelectric coupling properties of the laminated systems were compared with the mixed system having similar weight percentage of BaTiO3 and NiFe2O4. The fabricated composite systems show good multiferroic and magnetoelectric properties. Compared to mixed composite systems, the laminated structure has an enhanced magnetoelectric (ME) coupling of 6.42 mV/cm.Oe. This variation in ME coupling is attributed to the low leakage current effects in the laminated systems. The ME coupling in the laminates varies with the nature and number of layers. For laminated composite systems, the ME coupling coefficient is found to increase from 6.42 mV/cm.Oe to 10.48 mV/cm.Oe with increase in the number of layers. [ABSTRACT FROM AUTHOR]

Direct conversion from terahertz photon to charge current is a key phenomenon for terahertz photonics. Quantum geometrical description of optical processes in crystalline solids predicts existence of field-unbiased dc photocurrent arising from terahertz-light generation of magnetic excitations in multiferroics, potentially leading to fast and energy-efficient terahertz devices. Here, we demonstrate the dc charge current generation from terahertz magnetic excitations in multiferroic perovskite manganites with spin-driven ferroelectricity, while keeping an insulating state with no free carrier. It is also revealed that electromagnon, which ranges sub-terahertz to 2 THz, as well as antiferromagnetic resonance shows the giant conversion efficiency. Polar asymmetry induced by the cycloidal spin order gives rise to this terahertz-photon-induced dc photocurrent, and no external magnetic and electric bias field are required for this conversion process. The observed phenomena are beyond the conventional photovoltaics in semi-classical regime and demonstrate the essential role of quantum geometrical aspect in low-energy optical processes. Our finding establishes a paradigm of terahertz photovoltaic phenomena, paving a way for terahertz photonic devices and energy harvesting. Authors discover that the spin excitations of multiferroics convert the terahertz photon to the unidirectional charge current through the quantum geometrical aspect of optical process, paving the way to the terahertz photonics. [ABSTRACT FROM AUTHOR]

The discovery of novel two-dimensional (2D) multiferroic materials is attractive due to their potential for the realization of information storage and logic devices. Although many approaches have been explored to simultaneously introduce ferromagnetic (FM) and ferroelectric (FE) orders into a 2D material, the resulting systems are often plagued by weak magnetoelectric (ME) coupling or limited room-temperature stability. Here, we present a superlattice strategy to construct non-centrosymmetric AM2X4 multiferroic monolayers, i.e., intercalating transition metal ions (A) into the tetragonal-like vacancies of transition metal dichalcogenide bilayers (MX2). Starting from 960 intercalated AM2X4 compounds, our high-throughput calculations have identified 21 multiferroics with robust magnetic order, large FE polarization, low transition barrier, high FE/FM transition temperature, and strong ME coupling. According to the origin of magnetism, we have classified them into twelve type-a, seven type-b, and two type-c multiferroics, which exhibit different ME coupling behavior. During the switching of polarization, the reversal of skyrmions chirality, the transition of the magnetic ground state from FM to antiferromagnetic, and the changes in spin-polarized electron distribution were observed in type-a, type-b, and type-c 2D multiferroic materials, respectively. These results substantially expand the family of 2D ferroic materials and pave an avenue for designing and implementing nonvolatile logic and memory devices. [ABSTRACT FROM AUTHOR]

Magnetoelectric composite materials, which exhibit both ferroelectric and ferromagnetic properties simultaneously, have attracted considerable interest for their potential in various applications such as microelectronics, memory devices, and spintronics. In this study, we investigated the synthesis, structural, morphological, electrical, and magnetic properties of multiferroic CoFe2O4/0.65BiFeO3-0.35PbTiO3 (CFO/65BF-35PT) composite thin films. These films were prepared using a high ferroelectric, morphotropic phase boundary (MPB) composition, 65BF-35PT, combined with a high magnetostrictive compound, CFO. Multilayered CFO/65BF-35PT composite films were spin-coated onto fluorine-doped tin oxide (FTO)/glass substrates using the sol-gel method, with variation in the solution molarity to achieve different layer thicknesses. Structural analysis revealed a perovskite phase for 65BF-35PT and a spinal structure for CFO, with the presence of rhombohedral and tetragonal polymorphs confirming MPB composition. Scanning electron microscope images demonstrated uniform growth of 1 μm thick composite films. Ferroelectric hysteresis loops exhibited considerable leakage current at room temperature, increasing with higher CFO content, while current versus voltage plots revealed ohmic conduction at low applied fields and space charge limited current (SCLC) conduction at high fields in all composite films. The crossover field between ohmic and SCLC conduction decreased with increasing CFO content. Moreover, room-temperature magnetic hysteresis loops showed a decrease in saturation and coercive field with increasing CFO concentration, and the temperature-dependent magnetization response indicated a monotonic decrease, with magnetization vanishing around 800 K, confirming the magnetic order of CFO. Our findings demonstrate that stable ferroelectric and ferromagnetic phases can be achieved at low temperatures by depositing composite films containing CFO/MPB on a low-cost FTO substrate. [ABSTRACT FROM AUTHOR]

BiFeO 3 is a promising multiferroic material for versatile device applications due to its co-existence of magnetic (i.e., antiferromagnetic) and ferroelectric ordering at room temperature. While its functional properties have been extensively investigated, the exploration of its mechanical behavior was limited mostly to the thin-film form of BiFeO 3. In this work, we conducted in situ micropillar compression experiments to investigate the deformation behavior of La-doped BiFeO 3 (La-BFO) samples processed by both conventional and flash sintering methods. The conventionally sintered La-BFO exhibited limited deformability at room temperature and 450 °C. In contrast, the deformability of the flash-sintered La-BFO specimens was substantially improved by nearly 100% at both testing temperatures. Detailed post-mortem studies suggest that preexisting dislocations and wide anti-phase boundaries introduced during flash sintering can toughen flash-sintered La-BFO by easing dislocation migration and ferroelastic domain switching. This study provides a fresh perspective to design an advanced multifunctional system with improved mechanical properties. • Flash sintering introduced high population of pre-existing dislocations and anti-phase boundaries into La-BFO. • The flash sintered La-BFO deformed at room temperature exhibited an over 100% deformability enhancement. • At 450 °C, the flash-sintered La-BFO outperformed the conventionally sintered counterpart by showing plastic deformability. [ABSTRACT FROM AUTHOR]

We present a strategy for realizing the nonvolatile electrical control of noncollinear magnetism based on first-principles calculations. We confirm that the VAl2S4 monolayer, a rare two-dimensional type-II multiferroic material, shows an in-plane noncollinear 120°-ordered antiferromagnetic ground state and spin spiral order induced out-of-plane ferroelectricity. In VAl2S4 bilayers, we clarify the spin spiral chirality–sliding ferroelectricity locking effect, which enables flexible electrical switching of noncollinear magnetism and corresponding spin spiral chirality through interlayer sliding. Our work provides another perspective for the development of magnetoelectric physics and information storage devices. [ABSTRACT FROM AUTHOR]

The emergence of multiferroic materials, which possess both ferromagnetic (FM) and ferroelectric (FE) properties, drive advancements in magnetoelectric applications and the next generation of spintronics. Based on first-principles calculations, we investigate an engineered two-dimensional multiferroic van der Waals heterostructures consisting of FM VSiSnN4 monolayer (ML) and fully hydrogenated FE AlN bilayer. We find that the magnetic anisotropy of VSiSnN4 ML is tunable between out-of-plane and in-plane, and a phase transition between semiconductor and metal is induced in VSiSnN4/AlN bilayer when the FE polarization direction of AlN bilayer is reversed. Surprisingly, when the FE polarization of AlN bilayer is upward, the Curie temperature of VSiSnN4/AlN bilayer can be significantly increased from 204 to 284 K. Such nonvolatile and tunable magnetic anisotropy, Curie temperature, and band alignment in VSiSnN4/AlN multiferroic heterostructure are highly promising for future low-current operation of data storage and logic devices. [ABSTRACT FROM AUTHOR]

Single‐molecule toroics (SMTs), defined as a type of molecules with toroidal arrangement of magnetic moment associated with bi‐stable non‐magnetic ground states, are promising candidates for high‐density information storage and the development of molecule based multiferroic materials with linear magneto–electric coupling and multiferroic behavior. The design and synthesis of SMTs by arranging the magnetic anisotropy axis in a circular pattern at the molecular level have been of great interest to scientists for last two decades since the first detection of the SMT behavior in the seminal Dy3 molecules. DyIII ion has long been the ideal candidate for constructing SMTs due to its Kramer ion nature as well as high anisotropy. Nevertheless, other LnIII ions such as TbIII and HoIII ions, as well as some paramagnetic transition metal ions, have also been used to construct many nontraditional SMTs. Therefore, we review the progress in the studies of SMTs based on the nontraditional perspective, ranging from the 3D topological to 1D&2D&3D polymeric SMTs, and 3d–4f to non Dy‐based SMTs. We hope the understanding we provide about nontraditional SMTs will be helpful in designing novel SMTs. [ABSTRACT FROM AUTHOR]

In this work, h -RFeO 3 multiferroic high-entropy ceramics are designed by introducing high-entropy concept with four elements (Yb, Lu, In, Sc) for R site. (Yb 0.25 Lu 0.25 In 0.25 Sc 0.25)FeO 3 high-entropy ceramics are prepared by the standard solid-state reaction methods. The samples prepared with precursors were identified to crystalize in the pure hexagonal structure with polar space group (P 6 3 cm) at room temperature. By the analysis of the variable XRD patterns, it is speculated that the ferroelectric transition temperature of the sample is above 773 K. Meanwhile, three magnetic anomalies are determined for high-entropy ceramics, which is the antiferromagnetic transition at Néel temperature T Ñ 280 K, the spin-reorientation temperature T SR ∼145 K and the reasonable ferromagnetic-like clusters without long ordering in T N < T < T A (∼397 K). Besides, it is observed that the peak intensity of the pyroelectric current around T N can be tuned by magnetic field, which is indicated the magnetoelectric coupling effect in (Yb 0.25 Lu 0.25 In 0.25 Sc 0.25)FeO 3 high-entropy ceramics. These results indicate the ferroelectric and antiferromagnetic orders are coexist in the h- RFeO 3 high-entropy ceramics as promising near room temperature multiferroic materials, and it is an effective way to obtain a new type single-phase multiferroic materials. [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]

BiFeO3 is a multiferroic material, its tetragonality (T) phase usually exhibits large tetragonality (c/a ratio) and strong ferroelectricity. Unlike the commonly used method of strain engineering via substrate, here we present a general and practical approach for obtaining T-like phase BiFeO3 films through (Ba,Ca)TiO3 doping (BF-BCT). The BF-BCT film coherently grows on the La0.7Sr0.3MnO3/(La0.18Sr0.82)(Al0.59Ta0.41)O3 (001) substrate even at 180 nm thick, implying a very large critical thickness, and shows a large tetragonality of 1.12. Impressively, the films exhibit a giant remanent polarization (2Pr) of 320 μC/cm2, which is higher than the corresponding values of any other lead-free ferroelectric films reported to date. Cross-sectional scanning transmission electron microscopy measurements confirm the presence of the T-like phase in BF-BCT films, where the giant polarization might be attributed to the off-center B-site atom. The BF-BCT films are structurally homogeneous without any precipitation of the second phase. The giant polarization observed in the BF-BCT films indicate their great potential for application in next-generation storage and information devices. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) multiferroic materials are currently in high demand due to their significant potential for applications in the field of high-density data storage devices. However, due to the different requirements for generating ferroelectricity and magnetism, 2D multiferroic materials are rare. In this study, we propose that applying strain can induce magnetism in 2D ferroelectric materials with special electronic structures, thereby creating 2D multiferroics. Taking 2D ZnIn2S4 as an example, it shows robust ferroelectricity with an appropriate switching barrier (79.3 meV), and the out-of-plane ferroelectric polarization is 0.0322 C/m2. Applying biaxial tensile strain can change the energy of the flatband near the Fermi level, ultimately resulting in self-doping phenomena and leading to Stoner-type itinerant ferromagnetism. The reversal of ferroelectric polarization in ZnIn2S4 bilayer and ZnIn2S4–In2Se3 heterostructure can manipulate the magnetic moment of the system, exhibiting significant magnetoelectric coupling phenomena. Our findings provide a pathway for designing 2D ferromagnetic and multiferroic materials. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) multiferroic materials are currently in high demand due to their significant potential for applications in the field of high-density data storage devices. However, due to the different requirements for generating ferroelectricity and magnetism, 2D multiferroic materials are rare. In this study, we propose that applying strain can induce magnetism in 2D ferroelectric materials with special electronic structures, thereby creating 2D multiferroics. Taking 2D ZnIn2S4 as an example, it shows robust ferroelectricity with an appropriate switching barrier (79.3 meV), and the out-of-plane ferroelectric polarization is 0.0322 C/m2. Applying biaxial tensile strain can change the energy of the flatband near the Fermi level, ultimately resulting in self-doping phenomena and leading to Stoner-type itinerant ferromagnetism. The reversal of ferroelectric polarization in ZnIn2S4 bilayer and ZnIn2S4–In2Se3 heterostructure can manipulate the magnetic moment of the system, exhibiting significant magnetoelectric coupling phenomena. Our findings provide a pathway for designing 2D ferromagnetic and multiferroic materials. [ABSTRACT FROM AUTHOR]

The exploration of multiferroic materials and their interaction with light at the nanoscale presents a captivating frontier in materials science. Bismuth Ferrite (BiFeO3, BFO), a standout among these materials, exhibits room-temperature ferroelectric and antiferromagnetic behaviour and magnetoelectric coupling. Of particular interest is the phenomenon of photostriction, the light-induced deformation of crystal structures, which enhances the prospect for device functionality based on these materials. Understanding and harnessing multiferroic phenomena holds significant promise in various technological applications, from optoelectronics to energy storage. The orientation of the ferroelectric axis is an important design parameter for devices formed from multiferroic materials. Determining its orientation in the laboratory frame of reference usually requires knowing multiple wavevector transfer (Q-Vector) directions, which can be challenging to establish due to the need for extensive reciprocal-space searches. Our study demonstrates a method to identify the ferroelectric axis orientation using Bragg Coherent X-ray Diffraction Imaging (BCDI) measurements at a single Q-vector direction. This method involves applying photostriction-inducing laser illumination across various laser polarisations. Our findings reveal that photostriction primarily occurs as a surface phenomenon at the nanoscale. Moreover, a photo-induced crystal length change ranging from 30 to 60 nm was observed, consistent with earlier findings on bulk material. [ABSTRACT FROM AUTHOR]

BiFeO3‐BaTiO3‐based ceramics are promising multiferroic materials for a wide range of applications. In this paper, the effects of different ionic valence state((Ga0.5Ta0.5)4+, Ta5+) doping on the structure and properties of 0.73BiFeO3‐0.27BaTi1‐y(Ga1‐xTax)yO3 ceramics were investigated. X‐ray diffraction analysis showed that all samples were determined by rhombohedral R3c phase and tetragonal P4mm phase. A frequency‐independent dielectric anomaly with obvious thermal hysteresis was detected in all samples, indicating the first‐order ferroelectric phase transition, and the Curie temperatures were all above 600°C. The ferroelectric analysis found that the doping of donor element Ta reduced the coercive field, with a slight decrease of remanent polarization, which can be attributed to the soft effect of Ta element. Meanwhile, the magnetic properties were enhanced for all samples, with a maximum in 15T (x = 1, y =.015) sample, where Mr =.13 emu/g. According to relevant analysis, high‐valence element substitution can enhance the magnetic properties and reduce the coercive field of BiFeO3, while low‐valence element substitution can reduce dielectric loss. This result points out a way for us to choose appropriate doping elements to improve the performance of BiFeO3 ceramics. [ABSTRACT FROM AUTHOR]

BiFeO3 is a rare single‐phase multiferroic which shows coupled ferroelectricity, ferroelasticity and antiferromagnetism at room temperature. Many fantastic properties of BiFeO3 are regulated by its domain structure. While (001) rhombohedral BiFeO3 thin films can possibly develop up‐to eight degenerate states of two‐variant 71° ferroelastic domain stripes, complete selective control of all possible switching paths between these states has not yet been achieved. Here, combining phase field simulations and scanning probe microscopy experiments, we demonstrated such a complete selective control. The tip bias and the built‐in field were shown to affect the volume fraction of the 71°, 109° and 180° switched domains in rhombohedral BiFeO3 thin films under single‐point loading. Meanwhile, tip scanning further broke the symmetry of the nucleated domains, leading to different switched domain patterns. We then grew BiFeO3 thin films with a specific two‐variant 71° ferroelastic domain state and showed that such a state could be deterministically switched into the other seven two‐variant domain states by collaborative controlling tip scanning and tip bias in scanning probe microscopy experiments. These results should deepen our current understanding on the domain switching kinetics in BiFeO3 thin films and indicate they are promising platforms for developing configurable electronic and spintronic devices. [ABSTRACT FROM AUTHOR]

Searching for multiferroic materials with ferromagnetic (FM) and ferroelectric (FE) properties holds promise for ultra‐high‐density and low‐energy‐consumption memory device applications, but 2D materials with both properties are rare. Herein, a general strategy to achieve nonvolatile electric field control of magnetism in the bilayer (BL) α‐In2Se3 by hole doping is proposed. By first‐principles calculations, it is demonstrated that hole doping can induce robust ferromagnetism in the bilayer α‐In2Se3 due to its unique flat Mexican‐hat‐shape valence band structure. Such band edges cause van Hove singularities (VHS), and proper hole doping can lead to time‐reversal symmetry breaking. The bilayer α‐In2Se3 exhibits ferromagnetism and ferroelectricity within a wide range of doping concentrations, resulting in an unexpected multiferroic phase. Furthermore, when the electrical polarization of α‐In2Se3 flips from downward to upward, it becomes non‐magnetic (NM) from ferromagnetic states in the As‐substituted bilayer α‐In2Se3, which can work as a nonvolatile magnetic storage unit. Remarkably, the As‐substituted bilayer α‐In2Se3 exhibits an enhanced magnetic moment of 1.2 μB per AsSe due to substantial charge transfer across the interface. Notably, the mechanism of electrically controlled magnetism is elucidated as the coupling among the Mexican‐hat‐like dispersion, ferromagnetism, and ferroelectricity. The findings offer a promising strategy for electrical writing and the magnetic reading memory device. [ABSTRACT FROM AUTHOR]

Bi0.8Ba0.1Er0.1Fe0.96Cr0.02Mn0.02O3 (BBEFCMO) multiferroic ceramic was synthesized through the sol-gel route. The impact of incorporating various dopants into both A and B sites of the BiFeO3 was investigated, and structural, Raman, dielectric, electric, and magnetic properties were studied. X-ray diffraction analysis and Raman spectroscopy revealed a rhombohedral structure with the R3c space group for the doped material (BBEFCMO). Dielectric properties were examined across a frequency range of 102–106 Hz. The present multiferroic material exhibits a colossal dielectric constant and minimal dielectric loss tangent, making it suitable for applications in energy storage. Furthermore, the Cole-Cole type of relaxation was deduced from the imaginary part of the modulus for both grain and boundary-grain contributions. Overall, this study indicates that substituting ions in both A and B sites of BiFeO3 significantly enhances its multiferroic properties, as evidenced by dielectric and magnetic measurements. [ABSTRACT FROM AUTHOR]

We have investigated the magnetoelectric effect of a series of Y-type hexaferrite Ba0.8Sr1.2Co2Fe11.1−xAl0.9CrxO22 (x ≤ 0.4) at room temperature. Although the magnetoelectric voltage coefficient αE of these multiferroic hexaferrites is not high, it changes rapidly with an applied DC magnetic field, a phenomenon known as the giant magnetotranstance (GMT) effect. It is found that the GMT effect is enhanced with increasing content of Cr and reaches the maximum for x = 0.2. Specifically, the magnetotranstance ratio in the x = 0.2 sample is as high as −96% at 2000 Oe and −84% at 500 Oe. Further addition of Cr content causes a decay of the GMT effect. This kind of room-temperature GMT effect in Y-type hexaferrites opens up a route toward practical applications for the single-phase multiferroics. [ABSTRACT FROM AUTHOR]

Multiferroic materials have been developed and studied for decades due to their potential applications in microelectronics and spintronics, such as multi-state digital memories, energy storage, and ultra-fast electric field-controlled magnetic sensors. Among these materials, magnetoelectric multiferroics exhibit a magnetoelectric (ME) interaction allowing for the manipulation of polarization by a magnetic field and magnetization by an electric field through internal strain and/or charge. However, strain-mediated ME effect is time-consuming and inefficient at high frequencies (∼ GHz). To address this issue and pave the way toward high frequency applications of ME multiferroics, we have systematically designed and characterized layered Bi5FeTi3O15-type Aurivillius ceramics for a strong dynamic ME coupling in the GHz band. By introducing cobalt and niobium ions into Bi4.3Gd0.7FeTi3O15, a phase evolution from a four-layered structure to a mixed structure consisting of four- and three-layered phases was revealed. The Co/Nb co-doping was found to enhance the magnetization at room temperature while preserving ferroelectricity. The understanding of the substitution-enhanced dynamic ME coupling at satellite and radar communication frequencies is expected to broaden the range of applications for ME multiferroics. [ABSTRACT FROM AUTHOR]

Magnon, a quanta of spin waves, can transport in magnetically ordered insulators without substantial heat dissipation. The recently demonstrated magnon‐mediated spin torque through antiferromagnetic insulators is regarded as a highly efficient approach for electrical manipulation of magnetization. To control the magnon transport in antiferromagnets, a very large magnetic field is required, since antiferromagnets show immunity to external magnetic disturbance. The antiferromagnetic order can be electrically controlled in multiferroic materials via the magnetoelectric coupling between the antiferromagnetic and ferroelectric orders. Here, we report the experimental observation of magnon spin transport through multiferroic BiFeO3 thin films in SrRuO3/BiFeO3/NiFe tri‐layers at room temperature. We find highly efficient magnon current transmission through BiFeO3 thin film with a thickness exceeding 80 nm by the spin pumping measurement. The magnon spin‐torque efficiency in the tri‐layers measured by the spin‐torque ferromagnetic resonance is comparable with that in the SrRuO3/NiFe bilayer. This results suggest multiferroic BiFeO3 to be an excellent platform for investigating the antiferromagnetic magnon transport and developing magnonic devices. [ABSTRACT FROM AUTHOR]

This study investigates the gas sensing capabilities of bulk Bi 2(1-x) La 2x Fe 4 O 9 with x = 0, and 0.05 systems (BFO 0, BLFO 5), using a fiber optic VOC sensor at room temperature. Structural and magnetic characterizations confirm the successful incorporation of La3+ into the Bi site of the BFO 0 lattice without altering the structure. BLFO 5 exhibits remarkable gas sensitivity towards benzene, with a normalized gas sensitivity of 47 counts/100 ppm. This enhanced sensitivity is attributed to the presence of oxygen vacancies, which contribute to BLFO 5's weak ferromagnetism. The rapid response (43 s) and recovery (51 s) times further demonstrate the promising potential of multiferroic materials for VOC detection. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to learn the morphological, structural, ferroelectric, dielectric, electromechanical, magnetoelectric, and magnetic properties, and DC conductivity of BaTiO3-Ni0.64Zn0.36Fe2O4 (BT-F) multiferroic composites compacted via the free sintering method. The influence of the ferrite content in ceramic composite materials on the functional properties is investigated and discussed. X-ray diffraction studies confirmed the presence of two main phases of the composite, with strong reflections originating from BaTiO3 and weak peaks originating from nickel-zinc ferrite. BT-F ceramic composites have been shown to exhibit multiferroism at room temperature. All studied compositions have high permittivity values and low dielectric loss, while the ferroelectric properties of the BT component are maintained at a high level. On the other hand, magnetic properties depend on the amount of the ferrite phase and are the strongest for the composition with 15 wt.% of F (magnetization at RT is 4.12 emu/g). The magnetoelectric coupling between BT and F phases confirmed by the lock-in technique is the largest for 15 wt.% ferrite. In the present work, the process conditions of the free sintering method for obtaining BT-F multiferroic composite with good electrical and magnetic properties (in one material) were optimized. An improved set of multifunctional properties allows the expansion of the possibilities of using multiferroic composites in microelectronics. [ABSTRACT FROM AUTHOR]

In this work, pure and bentonite-Co-doped multiferroic Bi1-xBentxFe1-yCoyO3 (x = 0.00 – 0.03, y = 0.00 – 0.15) bismuth ferrite (BFO) nanoparticles (NPs) were synthesised using a cost-effective solvothermal process without using any mineraliser. A meticulous investigation has been made on the structural, magnetic, electric and visible light-driven photocatalytic properties of bentonite–cobalt-doped BFO NPs. The XRD patterns showed a well-arranged rhombohedral crystalline structure with space group R3c. The structural phase transformation has been observed from R3c to orthorhombic with the pnma group for Bi1-xBentxFe1-yCoyO3 samples. The SEM analysis confirmed the presence of components with villiform aggregates and new dense nanometric spots with an average crystal size of about 14 nm. The values of the dielectric constant of BFO NPs have been increased with bentonite–Co doping and are maximum (340 at 1 kHz) for x = 0.03 and y = 0.05 at 100 Hz. The saturation magnetisation value of 0.47 emu/g for BFO increases with bentonite-Co-doped BFO NPs to a maximum value of 1.79 emu/g for the Bi0.97Bent0.03Fe0.85Co0.15O3 sample. The energy band gap value of Eg = 2.99 eV for BFO decreases with bentonite–Co doping, and minimum value, Eg = 2.59 eV for the x = 0.03, y = 0.15 sample. The percentage degradation efficiency of undoped BFO NPs (64%) increased after bentonite–Co doping to 92% for the removal of methyl orange. The improved ferroelectric, magnetic and photocatalytic properties of bentonite–Co-doped BFO NPs offer new application in multiferroic-based energy storage devices as well as the removal of toxic dyes (methyl orange) from water. [ABSTRACT FROM AUTHOR]

Controlling the direction of ferromagnetism and antiferromagnetism by an electric field in single-phase multiferroics will open the door to the next generation of devices for spintronics and electronics. The typical magnetoelectric coupling such as the linear magnetoelectric effect is very weak in type-I multiferroics and therefore the magnetoelectric switching is rarely achieved. Here, using first-principles simulations, we propose a magnetoelectric switching mechanism to achieve such highly desired control in orthorhombic multiferroics. One class of two-dimensional proper multiferroics (CrX2Se3 and MnX2Te3, X = Sn, Ge) and perovskite multiferroics (EuTiO3 and BiFeO3/LaFeO3 superlattice) are taken as examples to show the mechanism. In the ferroelectric switching process, the proper polarization rotates its direction by 180° and keeps its magnitude almost unchanged, the ferromagnetic or antiferromagnetic vector is rotationally switched by 180° following the rotation of ferroelectric polarization. This rotational magnetoelectric switching results from in-plane structural anisotropy and magnetic anisotropy, and the process of switching is governed by cosine functions from the phenomenological Landau-type models. This study addresses the challenge of magnetoelectric switching in type-I multiferroics by proposing a general magnetoelectric switching mechanism. [ABSTRACT FROM AUTHOR]