Strong Magnetoelectric Coupling Effect Research Articles

Interface enhanced magnetoelectric coupling effect of multiferroic liquids based on CoFe2O4@BaTiO3 core shell particles

A new type CoFe2O4@BaTiO3 (CFO@BTO) multiferroic liquid with different CoFe2O4 (CFO) particle sizes was constructed, and its magnetic properties, electrical properties, and magnetoelectric coupling effects were systematically studied. XRD results show that the CFO phase has a spinel structure, whereas the BaTiO3 (BTO) phase has a perovskite structure, with no obvious heterophase formation. It can be seen from the SEM diagram that the CFO powder has a cuboid shape, and the CFO particle size (1.56 × 0.58 × 0.48µm, 3.16 × 1.04 × 0.66µm, 6.47 × 1.53 × 1.40µm, and 11.19 × 2.64 × 2.28µm) gradually increased with increasing calcination temperature(T = 450 ℃, 550 ℃, 650 ℃, 750 ℃). TEM results show that the composite particles have obvious core-shell structure. From the hysteresis loop, it can be seen that the saturation magnetization (Ms) of the CFO@BTO powder gradually increases with increasing CFO size. The sedimentation stability of the multiferroic liquid gradually decreases, the dielectric constant and residual polarization (Pr) decrease first and then increase, and the magnetoelectric coefficient and magnetoelectric coupling coefficient increase first and then decrease. When the particle size of the CFO is 6.47 × 1.53 × 1.40µm, the maximum magnetoelectric coupling coefficient is 210.76V/(cm·Oe) under an applied magnetic field of 50Oe, which realizes a strong magnetoelectric coupling effect at room temperature.

Optical and magnetoelectric coupling studies of ErCrO3

ErCrO3 samples were synthesized by solid state method. The structure, optical, magnetic, dielectric and low-temperature pyroelectric properties of the system were investigated. X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that the sample has an orthorhombic structure with the Pbnm space group, and an average particle size of 641 nm. Optical studies show that the optical band gaps are 2.1 eV and 3.2 eV for the sample. DC and AC magnetization indicate that ErCrO3 undergoes three magnetic phase transitions near TN (Cr3+), TSR, and TN(Er3+). Interestingly, another hump is observed in the range of 50–70 K during the AC magnetization measurements. Dielectric and pyroelectric measurements demonstrate significant anomalies in the dielectric permittivity and pyroelectricity around TN, TSR and the corresponding temperature of the hump. This suggests a close correlation between the dielectric and pyroelectric properties with the magnetic transition. Furthermore, the pyroelectric measurements at low temperatures prove that the magnetic field could regulate the electric polarization, a further proof of the strong magnetoelectric coupling effect in the system. These properties of ErCrO3 make it have significant applications in optoelectronic devices, storage devices, sensors, and so on.

Magnetoelectric coupling property of 0-3 type CoFe2O4-BaTiO3 nanocomposites

The 0-3 type CoFe2O4-BaTiO3 nanocomposites have been prepared by co-precipitation sintering process in this work. The structure, dielectric, magnetic properties and magnetoelectric (ME) coupling effect of nanocomposites are studied. It finds that the 0-3 connectivity in nanocomposites results in BaTiO3 hindering the merger and growth of CoFe2O4 leading to smaller particle size (in the range 52–55 nm), creating large interface area between CoFe2O4 and BaTiO3 in composites. Creating the space charge polarization dominant thereby the dielectric constant decreased sharply with increasing frequency. Magnetization data show typical ferromagnetic behavior. Nanocomposites have strong ME coupling effect, among which C40s (CoFe2O4 content is 40 wt%) sample has a maximum ME coupling coefficient of 587.3 mV/cm∙Oe at 1.8 kHz.

Significantly enhanced hybrid improper ferroelectricity of Ca3Ti2O7 ceramics by the oxygen vacancy engineering

Ca3Ti2O7 materials with hybrid improper ferroelectricity call tremendous interest due to their great potential in designing novel room-temperature single-phase multiferroics with a strong magnetoelectric coupling effect. However, achieving Ca3Ti2O7-based ceramics with superior room-temperature ferroelectricity remains a crucial challenge. Herein, Ca3Ti2O7 ceramics were prepared by a tartaric acid sol–gel method and sintered in air and oxygen atmospheres, respectively. It was found that the long-time high-temperature sintering in air could lead to the formation of CaTiO3/Ca3Ti2O7/CaTiO3 sandwich structure, and oxygen-enriched sintering could effectively avoid the formation of CaTiO3 phase on the surface. The superior hybrid improper ferroelectricity is attained in Ca3Ti2O7 ceramics sintered in oxygen atmosphere with a higher remnant polarization (3.63 μC/cm2) and lower coercive electric field (72.6 kV/cm) obtained by positive-up and negative-down method, which is better than the ceramic sample sintered in air. The significantly better ferroelectricity is benefited from the synergistic effects of its larger distortion of oxygen octahedron, larger grain size, and lower oxygen vacancy concentration. Due to its low leakage current density, Ca3Ti2O7 ceramics sintered in oxygen atmosphere exhibit the remanent polarization as high as 7.40 μC/cm2 under the conditions of 1 Hz and 200 kV/cm obtained by dynamic hysteresis measurement mode. Furthermore, there are obvious stripe ferroelectric domains, which provide direct evidence for the excellent hybrid improper ferroelectricity of Ca3Ti2O7 ceramics. These findings demonstrate that the oxygen vacancy engineering is an effective strategy to improve hybrid improper ferroelectricity of Ca3Ti2O7 materials.

Direct evidence of mutual control of ferroelectric polarization and magnetization in Y-type hexaferrite BaSrCo2Fe12-Al O22 ceramics

Hexaferrites that exhibit the intrinsic and strong magnetoelectric (ME) coupling effect have been considered the most promising candidate for single-phase multiferroics. Currently, the strong ME coupling effect in this system was widely reported in single crystal form, while it is rare in polycrystalline one. In this work, Y-type hexaferrite BaSrCo2Fe12-xAlxO22 (x = 0.0, 0.3, 0.6 and 0.9) ceramics were manufactured with conventional solid-state reaction. Their magnetic, dielectric, and ME coupling properties were systematically surveyed. It was revealed that Al doping could result in a high magnetic transition temperature of ~ 345 K for x = 0.9. Also, the ferroelectric polarization and abnormal magnetodielectric properties were significantly enhanced which could be maintained down to 200 K. Most interestingly, the sample x = 0.9 displayed strong direct and converse ME coefficients of ~ 400 ps/m and ~ 900 ps/m at 150 K, respectively. Therefore, these results reveal that Al doping can broaden our understanding of the Y-type hexaferrite in room-temperature multiferroics.

Enhanced dielectric, ferroelectric, and ferromagnetic properties of 0.7Bi1−xTmxFeO3–0.3BaTiO3 ceramics by Tm-induced structural modification

In this study, Tm-doped 0.7Bi1−xTmxFeO3–0.3BaTiO3 (x = 0–0.05) ceramics have been fabricated using traditional solid-phase reactions and their structural, morphological, and dielectric as well as multiferroic properties are investigated. X-ray diffraction and Rietveld refinement indicated the formation of a Tm-modulated morphotropic phase boundary (MPB) from the rhombohedral (R3c) and tetragonal (P4mm) phases to a single P4mm phase for Tm content of x = 0.02–0.03. Tm occupation of lattice sites is strongly suggested at both the A and B sites in the ABO3-type perovskite structure, which is supported by the obtained Raman spectra, the calculated tolerance factor, and dielectric relaxation characteristics. With the Tm-induced aforementioned–structural modification, the dielectric constant, remnant polarization (Pr), and remnant magnetization (Mr) values indicate that the dielectric and multiferroic properties are greatly improved. The obtained maximum remnant polarization (2Pr = 35.28 μC/cm2) and remnant magnetization (2Mr = 0.56 emu/g) are approximately two and seven times larger, respectively, than those of the sample without Tm substitution (x = 0). With increasing the Tm content, the remnant polarization, and the remnant magnetization exhibit almost the same trends in variation, indicating the possible existence of a relatively strong magnetoelectric coupling effect. Our study may provide a substitution strategy (structural modification by substituting the same element into two different lattice sites) to efficiently enhance the dielectric and multiferroic properties of BiFeO3–BaTiO3-based ceramics.

Effect of sintering temperature on magnetoelectric properties of PbTiO3/NiFe2O4 composite ceramics

ABSTRACT Magnetoelectric composites have attracted much attention due to their strong magnetoelectric coupling effect. In this paper, PbTiO3-NiFe2O4 (PTO/NFO) composite ceramics were prepared by sol-gel method. Effect of sintering temperatures on the structure, dielectric properties and multiferroic properties were studied. XRD results show that PTO/NFO ceramics have been successfully prepared. When the sintering temperature is 1050 °C, the secondary phase PbO2 exists in the ceramics. SEM results show that there were two kinds of grains with different sizes. EDS analysis suggested that the large particles are NFO and the small particles are PTO. The sintering temperature has a great influence on the dielectric and ferroelectric properties of the prepared ceramics. When the sintering temperature is 950 °C, the ceramics show the maximum dielectric constant at low frequency. When the sintering temperature is 1150 °C, the maximum residual polarization is 1.236 μC/cm2. The conductive mechanism of ceramics is dominated by Space Charge – Limited Conduction. The remanent magnetization and coercive field decrease with increasing the sintering temperature. The magnetoelectric coupling coefficient shows that ceramics have strong magnetoelectric coupling performance (5.7 V/cm·Oe).

Electric field control of molecular magnetic state by two-dimensional ferroelectric heterostructure engineering

Two-dimensional multiferroics have attracted tremendous attention due to their intriguing physics and promising applications. However, it has been a major challenge to discover and design two-dimensional multiferroic materials with large electric polarization and strong magnetoelectric coupling. In this work, we propose a strategy to design a two-dimensional van der Waals heterostructure with strong magnetoelectric coupling by stacking a transition metal phthalocyanine (TMPc) molecule with ferroelectric monolayer In2Se3. By first-principles electronic structure calculations, we predict that the magnetic states of the TMPc molecule can be controlled by electrically switching the polarization direction of In2Se3 using an external electric field. This strong magnetoelectric coupling effect originates from the interfacial charge transfer and orbital splitting, resulting in the different magnetic states of TMPc/In2Se3 heterostructures in two opposite ferroelectric phases. Based on the TMPc/In2Se3 heterostructure, a high-density magnetic memory device is proposed for pure electric writing and magnetic reading. Our predictions may open avenues for finding and designing multiferroic heterostructures by using two-dimensional ferroelectric materials and zero-dimensional magnetic molecules with a strong proximity effect.

Study on magnetoelectric properties of Ni0.5Zn0.5Fe2O4/Ba0.8Sr0.2TiO3 composite ceramics based on Bi2O3 as combustion aid

Ni0.5Zn0.5Fe2O4/Ba0.8Sr0.2TiO3 (NZFO/BST) composite ceramics with different additions of Bi2O3 (0%, 1%, 3%, and 5% wt) were synthesized via the solid-phase sintering method. XRD analysis indicates that the composite ceramics show bi-phase structure, without apparent secondly phases can be observed. SEM images show that all the specimens have relative dense structure, the grain size is in the range 1–2 μm. A certain amount of Bi2O3 is beneficial to grain growth, the average grain size of NZFO/BST ceramics increases from 179 to 297 nm when the concentration of Bi2O3 is 0 and 3%, respectively. EDS results indicate that the distribution of NZFO phase and BST phase is not uniform. The sample NZFO/BST-3%Bi2O3 not only has the largest dielectric constant (er) in the whole temperature range (25–500 °C), but also presents the smallest dielectric loss (tanδ) at high temperature region (> 400 °C), and the maximum tanδ value is less than 0.4 for all the samples, indicating excellent dielectric performance. Compared with other samples, the specimen NZFO/BST-3%Bi2O3 has the largest remnant polarization (~ 1.14 μC/cm2). The sample NZFO/BST-3%Bi2O3 has the largest leakage current density, while the ceramic NZFO/BST-5%Bi2O3 presents the opposite behavior, the value of leakage current of the sample NZFO/BST-3%Bi2O3 is about 7 times larger than that of the specimen NZFO/BST-5%Bi2O. All the composite ceramics show soft magnetic behavior, since Bi2O3 is a non-magnetic phase, addition of Bi2O3 will dilute the magnetic moment per unit volume so as to decrease the magnetic properties of the ceramics. The sample NZFO/BST-3%Bi2O3 has the second largest saturation magnetization (Mr) of 11.27 emu/g and the smallest coercive field (HC) ~ 3.54 Oe. All the samples show strong magnetoelectric coupling effect, the highest magnetoelectric coupling coefficient is ~ 47 Vcm−1Oe−1, which was obtained in the sample without addition of Bi2O3. In short, the addition of Bi2O3 not only affects the structure of composite ceramics, but also plays an important role in affecting the magnetoelectric performance.

Sintering temperature dependent electrical properties of sol–gel grown nanostructured Bi0.95Nd0.05FeO3 multiferroics

Multiferroic Bi0.9Nd0.1FeO3 (BNFO) nanoparticles were prepared by low cost sol–gel method. Different particle sizes were obtained by varying sintering temperature (700, 750, and 800 °C). Effect of sintering temperature on the structural, microstructural, and dielectric properties has been discussed. Strong magnetoelectric coupling effect observed for BNFO nanoparticle at room temperature. Magnetic field tunable dielectric relaxation process in BNFO nanoparticles.

Anomalous Magnetoelectric Coupling Effect of CoFe2O4–BaTiO3 Binary Mixed Fluids

We report an anomalous magnetoelectric coupling effect of CoFe2O4–BaTiO3 binary mixed fluids, which were prepared by distributing surfactant treated (oleic acid) magnetic CoFe2O4 and ferroelectric BaTiO3 nanoparticles into highly insulating base fluid (silicone oil). A strong coupling effect in this mixed fluid has been observed, in which both the remnant polarization/magnetization and coercive electric/magnetic field are found to be enhanced visibly in the presence of an external magnetic/electric field. Colossal converse and direct magnetoelectric coupling coefficients are estimated to be αH = 1.22 × 10–4Oe·cm/V and αE = 2.52 × 104 V/(cm·Oe), respectively. Moreover, this coefficient clearly depends on the volume fraction of the two kinds of particles and the applied external magnetic/electric field. Even more amazing, CoFe2O4 also shows a strong magnetoelectric coupling effect with a coefficient as high as 4.2 × 10–5 Oe·cm/V. Further analysis indicates that the aggregated, chain-like structure of the pa...

Magnetoelectric coupling tailored by the orientation of the nanocrystals in only one component in percolative multiferroic composites.

Novel 1–3 type multiferroic composite thin films were prepared via a simple 0–3 composite fabrication process. The orientation of the Ni0.5Zn0.5Fe2O4 (NZFO) nanocrystals in the BaTiO3–Ni0.5Zn0.5Fe2O4 (BTO–NZFO) composite thin films was controlled by magnetron sputtering, and the controlling effect of such orientation on magnetoelectric coupling was investigated in detail. The NZFO lattice in the BTO–NZFO composite thin films grew with (100) orientation under the induction of the (111) plane of Si. The transfer of substrate stress between the closely contacted grains also contributes to the orientation of the NZFO nanocrystals. The 0.6BTO–0.4(100)NZFO multiferroic composite thin film exhibited a magnetization strength of 9.2% at the Curie point of the BTO phase, showing extremely strong magnetoelectric coupling characteristics. This work provides an effective strategy for the development of high-performance multiferroic composites, and brings about new conception of realizing strong magnetoelectric coupling effect from the perspective of physical chemistry.

Magnetocapacitance and magnetoelectric coupling effect of Ni0.5Cu0.5Fe2O4/BaTiO3 mixed multiferroic fluids

Ni0.5Cu0.5Fe2O4/BaTiO3 (NCFO/BTO) mixed multiferroic fluids were prepared by distributing surfactant treated NCFO and BTO particles in to a highly-insulating base fluid, the magnetocapacitance and magnetoelectric coupling effect were investigated. The results indicate that the sample shows strong magnetoelectric coupling effect, in which both the coercive field Ec and remanent polarization Pr enhance obviously under the action of magnetic field, while the dielectric constant decreases with increasing the magnetic field, revealing negative magnetocapacitance phenomenon. Large direct magnetolectric coupling coefficient was estimated to be α ∼ 76 V/(cm−1.Oe), which is several orders of magnitude larger than that of conventional magnetoelectric composite ceramics. Further analysis indicates that the possibility of movement, aggregation and chain-like structure of the particles in the presence of external field is believed to be responsible for the observed negative magnetocapacitance and strong magnetoelectric coupling effect. The results show that the strong room temperature magnetoelectric effect of the mixed magnetoelectric fluids is the product of the deformation of the particle distribution and the utilization of clamping force under external field. This magnetoelectric coupling effect is different from that of conventional composite materials which is directly coupled via the interface interaction, which will be advantageous for practical applications.

Recent development and status of magnetoelectric materials and devices

The magnetoelectric (ME) materials and related devices have been attracting increasing research attention over the last few years. They exhibit strong ME coupling effect at room temperature, and electric field control of magnetization or magnetic field control of ferroelectric polarization can be achieved. The ME coupling effect brings novel functionalities to develop ultra-fast, low-power, and miniaturized electronics. Recent progress shows the performance of ME materials is further improved and the materials are used to develop many new types of electronics such as high-speed memory, radio frequency resonator, compact ME antenna, and weak magnetic field sensor. In this review, we present the overview in those fields with emphasis on both the opportunities and challenges for the application of ME materials and devices in the cutting-edge technologies.

Structural, multiferroic, dielectric and magnetoelectric properties of (1-x)Ba0.85Ca0.15Ti0.90Zr0.10O3-(x)CoFe2O4 lead-free composites

High performance lead-free multiferroic composites with strong magnetoelectric coupling effect are desired to replace lead-based ceramics in multifunctional device applications due to increasing environmental issues. We report crystal structure, ferroelectric, magnetic, dielectric and magnetoelectric properties of (1-x)Ba0.85Ca0.15Ti0.90Zr0.10O3-(x)CoFe2O4 (BCTZ-CFO) lead-free composites with x = 0.1, 0.3, 0.5, 0.7 and 0.9 synthesized by chemical solution method. BCTZ power was synthesized by sol-gel method while CFO was prepared by metallo-organic decomposition (MOD) method. The XRD results confirm successful formation of the BCTZ-CFO composites without presence of any impurity phase. At room temperature, the BCTZ-CFO composites show multiferroic behavior characterized by ferroelectric and ferromagnetic hysteresis curves. The composite having 10 wt% of CFO exhibited maximum polarization, remnant polarization and coercive field of Ps ∼ 5.1 µC/cm2, Pr ∼ 1.4 µC/cm2 and Ec ∼ 11.6 kV/cm respectively. The BCTZ-CFO composite with 90 wt% of CFO incorporation exhibits improved ferromagnetic properties with Ms ∼ 32 emu/g, Mr ∼ 11.7 emu/g and Hc ∼ 504 Oe. Mӧssbauer spectra analysis show two sets of six-line hyperfine patterns for BCTZ-CFO composites, indicating the presence of Fe3+ ions in both A and B sites. Increasing BCTZ content was found to decrease the hyperfine field strength at both sites and is consistent with the decreasing magnetic moment observed for the samples. The maximum dielectric constant value ε′ ∼ 678 is obtained at 1 MHz for composite with 10 wt% of CFO phase. The results indicate that the BCTZ-CFO composites are potential lead-free room temperature multiferroic systems.

The regulation of magnetoelectric coupling and magnetic exchange bias effects in La doped Bi5Ti3FeO15 multiferroic films

La doped Bi5Ti3FeO15 (BTFO) multiferroic films with various doping concentration were synthesized by chemical solution deposition method. The structure, ferroelectric, magnetic properties, and magnetoelectric coupling effect were systemically investigated. Room temperature magnetoelectric effect was obtained. And the magnetoelectric coupling and magnetic exchange bias effects are regulated by the doping concentration of La. Such regulation originates from the evolution of magnetic structure derived from doping rare earth La. The coexistence of ferromagnetic (FM) and antiferromagnetic (AFM) orders can be controlled by the doping concentration of La. Thus, the superexchange interaction between FM and AFM orders was enhanced strongly, which contributes to the strong magnetoelectric coupling effect. This work provides an avenue on regulating the magnetic structure and magnetoelectric coupling effects.

Strong magnetoelectric coupling effect of BiFeO3/Bi5Ti3FeO15 bilayer composite films

BiFeO3/Bi5Ti3FeO15 (BFO/BTFO) bilayer multiferroic composite films were deposited on Pt (100)/Ti/SiO2/Si substrates using chemical solution deposition. Well-defined microstructure, improved multiferroic properties, and strong magnetoelectric coupling effect were obtained at room temperature. Such strong magnetoelectric effect originates from not only spin–orbit coupling in spin-driven ferroelectric systems for respective single-phase multiferroic layer, but the interface coupling between BiFeO3 and Bi5Ti3FeO15 film layers. The present work provides a simple way to fabricate lead-free multiferroic films with strong magnetoelectric effect.

Giant magnetoelectric effect in negative magnetostrictive/piezoelectric/positive magnetostrictive semiring structure

Magnetoelectric (ME) Ni/PZT/TbFe2 and TbFe2/PZT composites with two semiring structures are prepared. The dependence between ME coupling and magnetostrictive property of the composite is discussed. Because Ni possesses negative magnetostrictive property and TbFe2 shows positive magnetostrictive property, the ME voltage coefficient of Ni/PZT/TbFe2 semiring structure is much larger than that of TbFe2/PZT. In these composites, the ME voltage coefficient increases and the resonance frequency gradually decreases with the increase of the semiring radius, showing that structural parameters are key factors to the composite properties. Due to the strong ME coupling effect, a giant ME voltage coefficient αE = 44.8 V cm−1 Oe−1 is obtained. This approach opens a way for the design of ME composites with giant ME voltage coefficient.

Optimization design for magnetoelectric coupling property of the magnet/bimorph composite

Magnetoelectric (ME) composite as one kind of ME material that can yield a strong coupling effect between magnetic and electric fields at room temperature, has drawn widespread attention for decades due to its rich physics contents and significant technological prospect. Except for traditional magnetostrictive/piezoelectric based ME composites, other ME composites have been reported, among which the magnet/piezo-cantilever composites show super strong ME coupling effect. The magnet/piezo-cantilever composite is generally composed of a piezoelectric cantilever and magnets attached at the free end of the cantilever, which realizes ME coupling by force moment-mediated magnetic torque effect and piezoelectric effect. Recently, various configurations of the magnet/piezo-cantilever composites for obtaining higher ME coupling coefficients have been proposed and demonstrated experimentally. However, few theoretical researches of these magnet/piezo-cantilever composites of different configurations have been carried out, which is of great importance for optimizing the design of ME coupling property of the magnet/piezo-cantilever composites. Here in this paper, a theoretical expression for the low-frequency ME coupling coefficient in the magnet/piezo-cantilever composite is deduced based on piezoelectric constitutive equations by using the theory of elastic mechanics. The typical magnet/bimorph composite is chosen as the theoretical model. Based on the deduced theoretical expression, the dependences of the lowfrequency ME coupling coefficients in the magnet/bimorph composite on material and structural parameters are numerically calculated. The results show that there are optimal thickness values of the piezoelectric layers in the magnet/bimorph composite with different metal thickness values and material constituents for achieving maximal lowfrequency ME coupling coefficients. The thicker the metal layer in the magnet/bimorph composite, the less insensitive the low-frequency ME coupling coefficient to the thickness of the piezoelectric layer will be. And the low-frequency ME coupling coefficient of the magnet/bimorph composite decreases when a metal with higher elastic module is selected for bimorph. For the magnet/bimorph composite consisting of hard piezoelectric ceramics (PZT-4), the low-frequency ME coupling coefficient is higher than that of the composite consisting of the soft counterpart ones (PZT-5 H), which is due to the hard piezoelectric ceramics with higher piezoelectric voltage coefficient than the soft counterpart ones. What is more interesting is that when the piezoelectric material in the magnet/bimorph composite is changed into relaxor ferroelectric single crystals Pb(Zn1/3 Nb2/3)O3-PbTiO3 (PZN-PT), an extremely high low-frequency ME coupling coefficient can be obtained, which is 3.8 and 5 times those of the 13 composites with hard and soft piezoelectric ceramics, respectively. This research gives a theoretical guidance for optimal design and practical applications of the magnet/Bimorph composite.

Direct Observation of Magnetic Field Induced Ferroelectric Domain Evolution in Self-Assembled Quasi (0-3) BiFeO3–CoFe2O4 Thin Films

Strain-mediated magnetoelectric (ME) coupling effect is expected in self-assembly heterostructures engineered by ferroelectric and ferromagnetic materials, contributing to the enhanced overall magnetoelectric effect. Microstructures as well as the connectivity configuration are considered to play a significant role in achieving efficient magnetoelectric properties. Different from the conventional (1-3) and (2-2) type composite films, we fabricate BiFeO3-CoFe2O4 (BFO-CFO) composite thin films with a novel quasi (0-3) type connectivity via a dual-target pulsed laser deposition process. The self-assembly growth mechanism has been studied, which demonstrates that the perovskite (BFO) matrix segments the connectivity of spinel (CFO) resulting in a quasi (0-3) composite. Direct observation of ferroelectric domain wall motion under external magnetic fields proves a strong magnetoelectric coupling effect in these (0-3) thin films. Our preliminary findings reveal the promising application potential of this new structure as multiferroic domain wall devices.