Single-phase Multiferroic Materials Research Articles

Robust Ferrimagnetism and Ferroelectricity in 2D ɛ-Fe2O3 Semiconductor with Ultrahigh Ordering Temperature.

2D single-phase multiferroic materials with the coexistence of electric and spin polarization offer a tantalizing potential for high-density multilevel data storage. One of the current limitations for application is the scarcity of the materials, especially those combine ferromagnetism and ferroelectricity at high temperatures. Here, robust ferrimagnetism and ferroelectricity in 2D ɛ-Fe2O3 samples with both single-crystalline and polycrystalline form are demonstrated. Interestingly, the polycrystalline nanosheets also exhibit easily switchable ferroelectric polarizations comparable to that of single crystals. The existence of grain boundary does not hinder the switching and retention of ferroelectric polarization. Furthermore, the ɛ-Fe2O3 nanosheets show ferrimagnetic and ferroelectric Curie temperatures up to 800K, which reaches record highs in 2D single-phase multiferroic materials. This work provides important progress in the exploration of 2D high-temperature single-phase multiferroics for potentially compact high-temperature information nanodevices.

A new class of single-phase multiferroics: Bismuth-based layered supercell oxide thin films—Current progress and future perspectives

Multiferroic materials, where ferroelectric and magnetic orders coexist, have ignited substantial research interest due to the achievable manipulation of magnetic orders using external electric fields, a feature that has garnered serious interest for memory storage applications. Nonetheless, naturally occurring single-phase multiferroic materials are scarce, thus constraining options for practical use. Over the last decade, bismuth-based layered supercell (LSC) oxides have emerged as novel candidates for multiferroics, catalyzing extensive investigations in this domain. Additionally, these LSC systems are known for their anisotropic structures and optical properties, making them promising for application in optics such as polarizers, beam splitters, and modulators. This thorough review explores the development and current advancements in multiferroic bismuth-based LSC materials. It covers the diverse nature of LSCs, detailing their microstructure, properties, and the mechanics of self-assembly formation. It also highlights the remarkable multifunctional characteristics of LSC-based nanocomposites, with a particular focus on their applications in electronics and optics. Moreover, this review examines the significant potential of LSCs in practical applications, particularly through their integration onto silicon and flexible substrates via heteroepitaxy and film transfer techniques. Finally, it offers insights into potential future research avenues and the broader implications of these versatile LSC materials.

Near room temperature hexagonal multiferroic (Yb0.25Lu0.25In0.25Sc0.25)FeO3 high-entropy ceramics

In this work, h-RFeO3 multiferroic high-entropy ceramics are designed by introducing high-entropy concept with four elements (Yb, Lu, In, Sc) for R site. (Yb0.25Lu0.25In0.25Sc0.25)FeO3 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 (P63cm) 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 TÑ280 K, the spin-reorientation temperature TSR∼145 K and the reasonable ferromagnetic-like clusters without long ordering in TN < T < TA (∼397 K). Besides, it is observed that the peak intensity of the pyroelectric current around TN can be tuned by magnetic field, which is indicated the magnetoelectric coupling effect in (Yb0.25Lu0.25In0.25Sc0.25)FeO3 high-entropy ceramics. These results indicate the ferroelectric and antiferromagnetic orders are coexist in the h-RFeO3 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.

Modeling and performance analysis of resonant self-biased magnetoelectric transducers

Compared with single-phase multiferroic materials, magnetoelectric (ME) composites composed of piezoelectric and magnetostrictive materials have great ME coupling, and have received widespread attention in various application fields. The application of ME devices in wireless power transfer (WPT) is attractive due to their compactness and ability to operate at lower frequencies than conventional coils. However, traditional ME composites rely on permanent magnets or electromagnets to provide biased magnetic fields, thus leading to problems such as high noise, large size, and high cost, which significantly hinder the advancement of miniaturized and high-performance ME devices. To solve this problem, a self-biased ME laminated structure based on the magnetization grading effect is proposed in this work. Using the equivalent magnetization and nonlinear magnetostrictive constitutive relationship, a finite element simulation model for a self-biased ME transducer operating in L-T mode is constructed. The ME coupling performances without DC bias in bending vibration mode and stretching vibration mode are studied. Based on the model, the corresponding experimental samples are prepared for measurement. The measurement results are in agreement with the simulation data, thereby validating the accuracy and effectiveness of the model. The measured results show that the Metglas/Galfenol/PZT-5A structure can exhibit more significant self-biased ME effect under the stretching resonance mode than under bending resonance mode. Its ME coefficient attains a notable value of 10.7 V·cm&lt;sup&gt;–1&lt;/sup&gt;·Oe&lt;sup&gt;–1&lt;/sup&gt; at 99.4 kHz, while ME power coefficient reaches 5.01 μW·Oe&lt;sup&gt;–2&lt;/sup&gt; at 97.9 kHz. Its on-load ME power coefficient can reach up to 4.62 μW·Oe&lt;sup&gt;–2&lt;/sup&gt; at 99.3 kHz without impedance matching. When an external bias magnetic field of 25 Oe is applied, these performance indexes increase significantly to 47.06 V·cm&lt;sup&gt;–1&lt;/sup&gt;·Oe&lt;sup&gt;–1&lt;/sup&gt; at 99.4 kHz and 82.13 μW·Oe&lt;sup&gt;–2&lt;/sup&gt; at 99.0 kHz, respectively. The simulation results further show that the performance of the self-biased ME transducer can be significantly improved by increasing the thickness of the high permeability layer. For example, by increasing the Metglas layer thickness from 30 μm to 90 μm, both the ME coefficient and ME power coefficient increase rapidly by 2.47 times and 6.96 times the original values, respectively. Self-biased ME transducers effectively reduce the dependence on external bias magnetic field, thereby providing a good approach for applying and developing ME composites in low-frequency WPT systems.

Ferroelectrically controlled electromagnetic and transport properties of VN2H2/Al2O3 van der Waals multiferroic heterostructures.

The vertical integration of a ferromagnetic monolayer and a ferroelectric monolayer into van der Waals heterostructures offers a promising route to achieve two-dimensional multiferroic semiconductors owing to the lack of intrinsic single-phase multiferroic materials in nature. In this study, we propose a VN2H2/Al2O3 van der Waals magnetoelectric multiferroic heterostructure and investigate its electronic, magnetic, and transport properties using density functional theory combined with the Boltzmann transport theory. The VN2H2 monolayer is a room-temperature ferromagnetic semiconductor with a band gap of 0.24 eV and a Curie temperature of 411 K, while the Al2O3 monolayer is a ferroelectric semiconductor with a polarization value of 0.11 C m-2. In the VN2H2/Al2O3 van der Waals heterostructures, the conversion between the metal and the semiconductor can be controlled by altering the polarization of the Al2O3 layer. The VN2H2/Al2O3 van der Waals heterostructure retains room-temperature ferromagnetism, and the reverse of polarization is accompanied with a change in the direction of the easy magnetization axis. In addition, electrostatic doping can significantly improve the conductivity of the downward polarization state and transform the upward polarization state from a metal to a half-metal, achieving 100% spin polarization. Our results thus pave the way for achieving highly tunable electromagnetic and transport properties in van der Waals magnetoelectric heterostructures, which have potential applications in next-generation low-power logic and memory devices.

A DFT study on the switching energy of multiferroic capacitor with stable single-phase multiferroic material

In spintronic technology, bismuth ferrite BiFeO3 (BFO) is a potential multiferroic material for multiferroic capacitor application. In present study, the impact of transition metals X = Co, Ni, Mn, Ti at the Fe-site and rare earth element lanthanum (La) at the Bi-site is investigated using DFT calculation in order to improve the structural stability, spin polarized electronic, and dielectric properties of bismuth ferrite for switching energy of multiferroic capacitor applications. The calculations are carried out in the Cambridge Serial Total Energy Package (CASTEP) code by using ultra-soft pseudopotential (USP). The substitution of La and X atoms alters the spin-polarizedelectronic and dielectric characteristics of BFO, leading to an increase in the density of states (DOS) around the Fermi level. The observed descending order of the structure stability of co-doped BFO is given as: LaCo > LaNi > LaMn co-doped BFO system. LaCo and LaNi co-substituted systems have shown high spin polarizations of 87.08 % and 82.20 % respectively. Low switching energies of 0.52 aJ and 0.72 aJ, respectively have been observed for LaCo and LaNi co-doped BFO systems for multiferroic RAM capacitor applications.

Novel multiferroic nanoparticles Sm1−xHoxFeO3 as a heavy metal Cr6+ ion removal from water

Novel multiferroic nanoparticles Sm1−xHoxFeO3 have been prepared using a simple citrate auto-combustion method. According to the X-ray diffraction (XRD) data, the multiferroic samples had an orthorhombic single phase structure. The field emission scanning electron microscope (FESEM) illustrated that the nanoparticles possessed a cotton-like morphology with a porous nature. The vibrating sample magnetometer (VSM) demonstrates the antiferromagnetic (AFM) behavior of the samples. The maximum magnetization (Mm) of Sm0.95Ho0.05FeO3 is five times greater than that of SmFeO3. The ferroelectricity of Sm1−xHoxFeO3 has Г2-spin structure. The antiferromagnetic (AFM) spin canting has a great effect on both the magnetization and the ferroelectricity of the investigated perovskites. Sm1−xHoxFeO3; 0.0 ≤ x ≤ 0.10 samples are concluded to be novel single-phase multiferroic materials capable of adsorbing toxic chromium (Cr6+) metal ions from water. A hydrogen potential of pH 6 is the best condition for precipitating chromium ions. The adsorption of Cr6+ ions on Sm1−xHoxFeO3 was studied using the Langmuir and Freundlich isotherm models.

Tunable self-biased magnetoelectric effect in magnetization-graded magnetoelectric composites

Magnetoelectric (ME) composites, which are magnetostrictive-piezoelectric composites, have garnered attention for use in various application fields owing to their large ME coupling compared with single-phase multiferroic materials. The maximum ME coupling is observed when an increased DC magnetic bias field is applied, which results in large devices with degraded sensitivity due to electromagnetic noise. To address this problem, a strong self-biased ME composite that generates the maximum ME response in a zero-bias field was proposed in this study. Highly self-biased ME composites were prepared by combining soft magnetic Ni and highly permeable Metglas magnetostrictive layers with a Pb(Mg1/3Nb2/3)O3–PbZrTiO3 piezoelectric single-crystal laminate structure and inducing a magnetization gradient. The maximum ME voltage value without a DC bias field was evaluated to be 4.2 V/cm∙Oe for an MMNPNMM (M: Metglas foil, N: nickel, P: PMN-PZT) structure, which is 625 % higher than that of conventional ME composites. Therefore, the relatively bulky means of the DC-bias application on ME materials could be eliminated, resulting in a simple ME device with a small volume using the magnetization gradient concept.

High-entropy enhanced room-temperature ferroelectricity in rare-earth orthoferrites

Single-phase multiferroic materials of rare-earth orthoferrites with magnetism and ferroelectricity are of great technological importance in storage devices. However, the polarization of these materials is generally weak (0.01 μC×cm⁻²), and the ferroelectricity is reported to exist below room temperature. Here, (Bi_0.2La_0.2Y_0.2Dy_0.2Tb_0.2)FeO₃(BLYDTFO) high entropy oxide that exhibits a saturation polarization of 5.3 μC×cm⁻² at the electric field of 45 kV×cm⁻¹ at room temperature was designed and fabricated by the conventional solid phase method. The results show that the configurational entropy introduces atomic disorder and a larger tilt of BO₆ octahedron, which facilitates a non-centrosymmetric distortion and ferroelectricity at room temperature compared with other single components (LaFeO₃, YFeO₃, DyFeO₃, and TbFeO₃). This high-entropy approach expands the compositional window of rare-earth orthoferrites to enhance ferroelectricity in multiferroic applications.

A FEM-BEM coupling strategy for the modeling of magnetoelectric effects in composite structures

This paper deals with the numerical modeling of devices based on magnetoelectric composite materials. These heterogeneous structures made of the mechanical association of piezoelectric and magnetostrictive materials display magneto-electric effects exceeding by several orders of magnitude the response of single-phase multiferroic materials. A coupling of the Finite Element Method (FEM) and the Boundary Element Method (BEM) is used to model the behavior of magnetic effects, while classical FEM formulations are used for the electrical and mechanical problems. This coupling of numerical methods allows avoiding considering a free space domain around the active domain, and thus to use a single mesh for the magnetic, mechanical and electrical problems. This results in a consequent reduction of the number of unknowns, which is accompanied by shorter computation times compared to a pure FEM approach. The final system of equations is solved by a block Gauss–Seidel type solver.

Magnetoelectric coupling at microwave frequencies observed in bismuth ferrite-based multiferroics at room temperature

• Room-temperature single phase multiferroic materials was obtained • Magnetoelectric coupling was observed at microwave (GHz) frequency • The coupling suggests a dynamic interaction between magnetic moments and ferroelectric polarization 0.63Bi 0.99 La 0.01 Fe 1- x Mn x O 3 -0.33BaTiO 3 -0.04Na 0.5 Bi 0.5 TiO 3 ( x = 0.10, 0.15, and 0.20) ceramics have been prepared by solid state reaction, and their structural, ferroelectric, ferromagnetic, piezoelectric, and magnetoelectric properties are studied. Except for the x = 0.2 composition, the X-ray diffraction and SEM-EDX analysis on the sintered ceramics show that the samples are single-phase, rhombohedral perovskites at room temperature. The introduction of Mn ions leads to a small deterioration in the ferroelectric and piezoelectric properties, whilst the room-temperature magnetization increases upon doping. The optimal multiferroic properties are obtained for the x = 0.15 composition. The magnetoelectric coupling in this sample was evidenced by the anomalies occurring simultaneously in the dielectric permittivity and magnetic permeability spectral profiles in the microwave region. Such a coupled phenomenon can be attributed to a dynamic interaction between magnetic moments and ferroelectric polarization.

Domain-wall magnetoelectric coupling in multiferroic hexagonal YbFeO3 films

Electrical modulation of magnetic states in single-phase multiferroic materials, using domain-wall magnetoelectric (ME) coupling, can be enhanced substantially by controlling the population density of the ferroelectric (FE) domain walls during polarization switching. In this work, we investigate the domain-wall ME coupling in multiferroic h-YbFeO3 thin films, in which the FE domain walls induce clamped antiferromagnetic (AFM) domain walls with reduced magnetization magnitude. Simulation according to the phenomenological theory indicates that the domain-wall ME effect is dramatically enhanced when the separation between the FE domain walls shrinks below the characteristic width of the clamped AFM domain walls during the ferroelectric switching. Experimentally, we show that while the magnetization magnitude remains same for both the positive and the negative saturation polarization states, there is evidence of magnetization reduction at the coercive voltages. These results suggest that the domain-wall ME effect is viable for electrical control of magnetization.

Achieving High-Temperature Multiferroism by Atomic Architecture

Materials with multiple order parameters, typically, in which ferroelectricity and magnetism are coupled, are illuminative for next-generation multifunctional electronics. However, searching for such single-phase multiferroics is challenging owing to antagonistic orbital occupancy and chemical bonding requirements for polarity and magnetism. Appropriate multiferroic candidates have been proposed, but their practical implementation is impeded by the low working temperature, weak coupling between ferroic orders, or antiparallel spin alignment in magnetic sublattices. Here, we report a family of single-phase multiferroic materials in which high-temperature magnetism and voltage-switchable ferroelectricity are coupled. Using pulsed laser deposition, we have fabricated single-crystalline thin films incorporating a uniformly percolated open-shell dn framework, which are composed of Fe cations with B-site occupancy and exhibit long-range spin ordering into the displacive ferroelectric PbTiO3 lattice, as demonstrated by atomically resolved chemical analysis. The tetragonal polar Pb(Ti1-x,Fex)O3 (PFT(x), x ≤ 0.10) family exhibits a switchable ferroelectric nature and magnetic interaction with a moderate coercive field of around 300 Oe at room temperature. Notably, the magnetic order even persists above 500 K, which is higher than already reported potential multiferroic candidates until now. Our strategy of merging a spin-ordered sublattice into inherent ferroelectrics via atomic occupancy engineering provides an available pathway for highly thermally stable multiferroic and spintronic applications.

Phase Transitions in Magneto-Electric Hexaferrites.

Hexaferrites have long been the object of extensive studies because of their great possibility for applications-permanent magnets, high-density recording media, microwave devices, in biomedicine, to name but a few. Lately, many researchers' efforts have been focused on the existence of the magneto-electric effect in some hexaferrite systems and the appealing possibility of them being used as single-phase multiferroic and magneto-electric materials. As indicated by theoretical analyses, the origin of the large magneto-electric effect can be sought in the strong interaction between the magnetization and the electric polarization that coexist in insulators with noncollinear magnetic structures. The hexaferrites' magnetic structure and, particularly, the specific magnetic spin ordering are the key factors in observing magneto-electric phases in hexaferrites. Some of these phases are metastable, which hampers their direct practical use. However, as the hexaferrites' phase diagrams reveal, chemical doping can be used to prepare a number of noncollinear stable magnetic phases. Since the magneto-electric effect has to do with the magnetic moments ordering, it seems only logical that one should study the cation substitutions' influence on the magnetic phase transition temperature. In this paper, we summarize recent examples of advances in the exploration of magnetic phase transitions in Y-type hexaferrites. In particular, the effect is emphasized by substituting in Y-type hexaferrites the nonmagnetic Me2+ cations with magnetic ones and of the magnetic Fe3+ cations with nonmagnetic ones on their magnetic properties and magnetic phase transitions. The work deals with the structural properties of and the magnetic phase transitions in a specific Y-type hexaferrite, namely, Ba(Sr)2Me2Fe12O22.

Electric-field control of magnetization reversal at room temperature in SmFeO3 single-phase multiferroic thin film

Rare-earth orthoferrite SmFeO3 (SFO) is a promising single-phase multiferroic material because of simultaneous coexistence of magnetic and ferroelectric orders at room temperature (RT). However, the spin structures within this bulk material are antiferromagnetic arrangements, and the magnetoelectric (ME) coupling effect is weak. Thus, the realization of electric control of magnetization reversal at RT remains challenging. In this work, SFO thin films with different thicknesses of 30 nm, 60 nm and 90 nm were constructed onto LaNiO3 (LNO)-buffered LaAlO3 (LAO) substrates by pulsed laser deposition (PLD) method. The X-ray diffraction (XRD) θ-2θ scans and reflection high-energy electron diffraction (RHEED) patterns demonstrate the SFO is perfect growth along the LAO (00 l) direction. Besides, the magnetic measurement results indicate that all the thin films are induced obvious RT ferromagnetism by compressive strain of substrates. More importantly, when providing a pair of opposite polarization voltages of± 2.5 V for the 90 nm thin film, the ferroelectric and induced ferromagnetic domains at the same local area can realize synchronous reversal, which shows that the SFO thin film under compressive strain is a rare ferromagnetic-based ME multiferroic material at RT. This kind of material will produce wide application prospect in future electric-write magnetic-read high-density memories and other spintronics devices.

High-Magnetic-Sensitivity Magnetoelectric Coupling Origins in a Combination of Anisotropy and Exchange Striction.

Magnetoelectric (ME) coupling is highly desirable for sensors and memory devices. Herein, the polarization (P) and magnetization (M) of the DyFeO3 single crystal were measured in pulsed magnetic fields, in which the ME behavior is modulated by multi-magnetic order parameters and has high magnetic-field sensitivity. Below the ordering temperature of the Dy3+-sublattice, when the magnetic field is along the c-axis, the P (corresponding to a large critical field of 3 T) is generated due to the exchange striction mechanism. Interestingly, when the magnetic field is in the ab-plane, ME coupling with smaller critical fields of 0.8 T (a-axis) and 0.5 T (b-axis) is triggered. We assume that the high magnetic-field sensitivity results from the combination of the magnetic anisotropy of the Dy3+ spin and the exchange striction between the Fe3+ and Dy3+ spins. This work may help to search for single-phase multiferroic materials with high magnetic-field sensitivity.

Superior hybrid improper ferroelectricity and enhanced ferromagnetism of Ca3(Ti1-xCox)2O7 ceramics through the superexchange interaction

Ca3(Ti1-xCox)2O7 ceramics were prepared by a tartaric acid sol-gel method and sintered in an oxygen atmosphere. The introduction of Co2+/Co3+ as acceptor dopants leads to the formation of more oxygen vacancies and defect dipoles in Ca3(Ti1-xCox)2O7 ceramics. Oxygen vacancy and defect dipoles lead to the transition of dielectric, leakage, and ferroelectric behaviors of Ca3(Ti1-xCox)2O7 ceramics. The coexistence of hybrid improper ferroelectricity and ferromagnetism at room temperature in Ca3(Ti1-xCox)2O7 ceramics has been successfully realized through the superexchange interaction of Co–O–Co. Ca3(Ti1-xCox)2O7 ceramics exhibit superior ferroelectricity (the remnant polarization is 3.29 μC/cm2) and enhanced ferromagnetism (the remnant magnetization reaches 6.4×10−3 emu/g). This strategy based on the introduction of transition metal ions with unfilled 3d shells at B sites is an important approach to realize novel room-temperature single-phase multiferroic materials for Ca3Ti2O7-based materials.

Room-temperature multiferroic behaviour in Co/Fe co-substituted layer-structured Aurivillius phase ceramics

Room-temperature single-phase multiferroic materials have attracted the considerable attention of may scientists due to their technological applications in the next-generation electronic devices. Here, we report the structural evolution and its relationship with the ferroelectric and magnetic properties of Aurivillius Bi3.25Sm0.75Ti(3-x) (Fe,Co)xO12 (BSmT:FCx); for (0≤x ≤ 0.4) ceramics to elucidate the room-temperature multiferroics induced by Fe/Co co-substitution. The XRD analysis and structural refinements reveal that incorporating of Co, and Fe ions into Ti sites of BSmT host lattices gives rise to a single orthorhombic phase with no evidence of secondary phases. The X-ray photoelectron spectroscopy (XPS) spectra indicate the existence of oxygen vacancies in the investigated samples. Pure BiT samples exhibit diamagnetic behavior, while BSmT:FCx; for (0≤x ≤ 0.4) exhibits ferromagnetic behavior at room temperature. As a result, the sample with x = 0.4 displayed the highest remnant and saturation magnetization values. It is believed that the occurrence of magnetism causes by the magnetic double exchange interaction between the non-equivalent magnetic ions and oxygen. The reversible polarization induced by an electric field indicates the ferroelectric character of the ceramics at room temperature. The co-substituting samples show unsaturated P-E hysteresis loops, which could be caused by the domain pinning induced by the accumulation of oxygen vacancies near the domain boundaries. We expect these compounds are promising for developing electronic devices for future applications.

Multifunctional characterization of multiferroic [Pb(Fe0.5Nb0.5)O3]0.5 - [(Ca0.2Sr0.8)TiO3]0.5 for storage and photocatalytic applications

[(Ca0.2Sr0.8)TiO3] substituted [Pb(Fe0.5Nb0.5)O3] ceramic oxide with the formulation [Pb(Fe0.5Nb0.5)O3]0.5 - [(Ca0.2Sr0.8)TiO3]0.5 was manufactured by using solid state route. Rietveld analysis revealed that the compound crystallizes in single phase pseudocubic structure. The crystallite size and micro-strain were studied by Scherrer's and Williamson-Hall analyses. The functional group vibrations were analyzed by Fourier transform infrared (FTIR) analysis. The structural and optical vibrations were studied by Raman spectroscopy. The surface morphology was analyzed by field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDS) analysis was conducted to check the purity. The chemical structure and valence of the involved elements were examined by incorporating the X-ray photoelectron spectroscopy (XPS). Electron paramagnetic resonance technique was adopted to interpret the presence oxygen vacancy in the sample. UV–Visible spectroscopy was performed to evaluate energy band gap and Urbach energy. The effect of oxygen vacancies, disorder and electronegativity on band gap were studied. The thermodynamical aspect of photocatalytic property was analyzed by Mulliken's electronegativity approach. The photocatalytic response was studied by accounting for the degradation of methyl orange under visible illumination. Dielectric analysis was carried out to analyze the temperature dependence of dielectric constant and loss tangent revealing the sample's storage applications. The multiferroic property was investigated by means of room temperature P-E loop and M − H hysteresis loop. The observed ferromagnetism was explained by incorporating the most convenient bound magnetic polaron (BMP) model. The article provides detailed information about the paramagnetic octahedral structure of high spin Fe – nuclei through Mössbauer spectroscopy analysis. The current article provides a detailed insight about the synthesis and characterization of a new multiferroic oxide which can be used for photocatalytic device applications. The narrow band gap and weak multiferroicity are the interesting outcomes of this investigation which may provide a new revived single phase multiferroic material for advance electro-optical applications.

Hydrogen-Intercalated 2D Magnetic Bilayer: Controlled Magnetic Phase Transition and Half-Metallicity via Ferroelectric Switching.

Electrically controlled magnetism in two-dimensional (2D) multiferroics is highly desirable for both fundamental research and the future development of low-power nanodevices. Herein, inspired by the recently experimentally realized 2D antiferromagnetic MnPSe3 [ Nat. Nanotechnol. 2021, 16 (7), 782] and guided by a heteromagnetic structural design, we engineer strong magnetoelectric coupling in a hydrogen-intercalated 2D MnPSe3 bilayer. Hydrogen functionalization breaks the centrosymmetry of bilayer MnPSe3, leading to out-of-plane ferroelectricity. Moreover, there is a phase transition from antiferromagnetic semiconductor to ferromagnetic half-metal in the H-bonded MnPSe3 layer, while the other remains antiferromagnetic and semiconducting. When reversing the electrical polarization, the intercalated H atom can flip between the top and bottom layers with an ultralow switching barrier, which allows one to tune the magnetic order and conductivity of the individual layers via an external electric field. Our results pave a new avenue to realize strong magnetoelectric coupling in single-phase multiferroic material. The ferroelectricity-controlled magnetic phase transition and half-metallicity offer promising applications in nanoscale spintronics such as electrically written and magnetically read memories.