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In the present work, we have synthesized rare-earth ion modified Bi4−xRExTi2Fe0.7Co0.3O12−δ (RE = Dy, Sm, La) multiferroic compounds by the conventional solid-state route. Analysis of X-ray diffraction by Rietveld refinement confirmed the formation of a polycrystalline orthorhombic phase. The morphological features revealed a non-uniform, randomly oriented, plate-like grain structure. The peaks evident in the Raman spectra closely corresponded to those of orthorhombic Aurivillius phases. Dielectric studies and impedance measurements were carried out. Asymmetric complex impedance spectra suggested the relaxation of charge carriers belonging to the non-Debye type and controlled by a thermally activated process. Temperature-dependent AC conductivity data showed a change of slope in the vicinity of the phase transition temperature of both magnetic and electrical coupling natures. Based on the universal law and its exponent nature, one can suppose that the conduction process is governed by a small polaron hopping mechanism but significant distortion of TiO6 octahedral. The doping of the A-sites with rare-earth element ions and changes in the concentrations of Fe and Co ions located on the B-sites manifested themselves in saturated magnetic hysteresis loops, indicating competitive interactions between ferroelectric and canted antiferromagnetic spins. The magnetic order in the samples is attributed to pair-wise interactions between adjacent Fe3+–O–Fe3+, Co2+/3+–O–Co3+/2+, and Co2+/3+–O–Fe3+ ions or Dzyaloshinskii–Moriya interactions among magnetic ions in the adjacent sub-lattices. As a result, enhanced magnetoelectric coefficients of 42.4 mV/cm-Oe, 30.3 mV/cm-Oe, and 21.6 mV/cm-Oe for Bi4−xDyxTi2Fe0.7Co0.3O12−δ (DBTFC), Bi4−xLaxTi2Fe0.7Co0.3O12−δ (LBTFC), and Bi4−xSmxTi2Fe0.7Co0.3O12−δ (SBTFC), respectively, have been obtained at lower magnetic fields (<3 kOe). The strong coupling of the Aurivillius compounds observed in this study is beneficial to future multiferroic applications. [ABSTRACT FROM AUTHOR]

We report the magnetic-field-assisted electric-field-controlled domain switching of a magnetic single domain in a multiferroic/magnetoelectric Ni nanochevrons/[Pb(Mg1/3Nb2/3)O3]0.68–[PbTiO3]0.32 (PMN–PT) layered structure. Initially, a magnetic field was applied in the transverse direction across single-domain Ni nanochevrons to transform each of them into a two-domain state. Subsequently, an electric field was applied to the layered structure, exerting the converse magnetoelectric effect to transform/release the two-domain Ni nanochevrons into one of two possible single-domain states. Finally, the experimental results showed that approximately 50% of the single-domain Ni nanochevrons were switched permanently after applying our approach (i.e., the magnetization direction was permanently rotated by 180 degrees). These results mark important advancements for future nanoelectromagnetic systems. [ABSTRACT FROM AUTHOR]

In the present work, we have synthesized rare-earth ion modified Bi4−xRExTi2Fe0.7Co0.3O12−δ (RE = Dy, Sm, La) multiferroic compounds by the conventional solid-state route. Analysis of X-ray diffraction by Rietveld refinement confirmed the formation of a polycrystalline orthorhombic phase. The morphological features revealed a non-uniform, randomly oriented, plate-like grain structure. The peaks evident in the Raman spectra closely corresponded to those of orthorhombic Aurivillius phases. Dielectric studies and impedance measurements were carried out. Asymmetric complex impedance spectra suggested the relaxation of charge carriers belonging to the non-Debye type and controlled by a thermally activated process. Temperature-dependent AC conductivity data showed a change of slope in the vicinity of the phase transition temperature of both magnetic and electrical coupling natures. Based on the universal law and its exponent nature, one can suppose that the conduction process is governed by a small polaron hopping mechanism but significant distortion of TiO6 octahedral. The doping of the A-sites with rare-earth element ions and changes in the concentrations of Fe and Co ions located on the B-sites manifested themselves in saturated magnetic hysteresis loops, indicating competitive interactions between ferroelectric and canted antiferromagnetic spins. The magnetic order in the samples is attributed to pair-wise interactions between adjacent Fe3+–O–Fe3+, Co2+/3+–O–Co3+/2+, and Co2+/3+–O–Fe3+ ions or Dzyaloshinskii–Moriya interactions among magnetic ions in the adjacent sub-lattices. As a result, enhanced magnetoelectric coefficients of 42.4 mV/cm-Oe, 30.3 mV/cm-Oe, and 21.6 mV/cm-Oe for Bi4−xDyxTi2Fe0.7Co0.3O12−δ (DBTFC), Bi4−xLaxTi2Fe0.7Co0.3O12−δ (LBTFC), and Bi4−xSmxTi2Fe0.7Co0.3O12−δ (SBTFC), respectively, have been obtained at lower magnetic fields (

Multiferroic materials with coexisting of at least two ferroic orders (ferromagnetic, ferroelectric, or ferroelastic) have recently attracted the interest of researchers due to their potential applications as multifunctional devices. Herein, we report the synthesis and detailed characterization of the multiferroic CoFe2O4–Ba0.95Ca0.05Ti0.89Sn0.11O3 core–shell nanofibers (CFO@BCTSn NFs) prepared by a sol–gel coaxial electrospinning technique. The scanning and transmission electron microscopes were used to check nanofibers' core–shell structure/configuration, with fiber diameters ranging from 150 to 250 nm. The X-ray diffraction analysis confirms the presence of both the spinel structure of the CFO and the perovskite structure of the BCTSn. Piezoresponse force microscopy and magnetic hysteresis were used to confirm the multiferroicity of CFO@BCTSn NFs. Notably, the maximum magnetization and remanent magnetization of NFs are found to be 11.63 emu g–1 and 1.43 emu g–1, respectively. Meanwhile, the maximum piezoelectric response d33eff is around 6 pm V–1. The magnetoelectric (ME) coefficient obtained for the CFO@BCTSn NFs is 346 mV cm–1 Oe–1 at the field of 10 kG. These findings may lead to development of nanoscale Pb-free magnetic field sensors and magnetoelectric device applications. [ABSTRACT FROM AUTHOR]

The magnetoelectric properties of exchange-coupled Ni/CoFeB-based composite multiferroic microstructures are investigated. The strength and sign of the magnetoelastic effect are found to be strongly correlated with the ratio between the thicknesses of two magnetostrictive materials. In cases where the thickness ratio deviates significantly from one, the magnetoelastic behavior of the multiferroic microstructures is dominated by the thicker layer, which contributes more strongly to the observed magnetoelastic effect. More symmetric structures with a thickness ratio equal to one show an emergent interfacial behavior which cannot be accounted for simply by summing up the magnetoelastic effects occurring in the two constituent layers. This aspect is clearly visible in the case of ultrathin bilayers, where the exchange coupling drastically affects the magnetic behavior of the Ni layer, making the Ni/CoFeB bilayer a promising next-generation synthetic magnetic system entirely. This study demonstrates the richness and high tunability of composite multiferroic systems based on coupled magnetic bilayers compared to their single magnetic layer counterparts. Furthermore, because of the compatibility of CoFeB with present magnetic tunnel junction-based spintronic technologies, the reported findings are expected to be of great interest for the development of ultralow-power magnetoelectric memory devices.

In this work, we have prepared intergrowth of multiferroic compounds namely Bi4RTi3Fe0.7Co0.3O15-Bi3RTi2Fe0.7Co0.3O12−δ (BRTFCO15-BRTFCO12) (rare earth (R) = Dy, Sm, La) by solid-state reaction method. From the X-ray diffraction Rietveld refinement, the structure of the intergrowths was found to be orthorhombic in which satisfactory fittings establish the existence of three-layered (space group: b 2 c b) and four-layered compounds (space group: A21am). Analysis of magnetic measurements confirmed a larger magnetization for theSm-modified intergrowth compound (BSTFCO15-BSTFCO12) compared to Dy- and La-doped ones. The emergence of higher magnetic properties can be due to distortion in the unit cell when some Bi3+ ions are replaced with the Sm3+, bonding of Fe3+-O-Co3+ as well as a possible mixture of FexCoy-type nanoparticles that are formed generally in the synthesis of intergrowths. The changes in the magnetic state of the Aurivillius intergrowths have been reflected in the magnetoelectric (ME) coupling: higher ME coefficient (~30 mV/Cm-Oe) at lower magnetic fields and is constant up to 3 kOe. The results were corroborated by Raman spectroscopy and variation of temperature with magnetization data. The results revealed that the RE-modified intergrowth route is an effective preparative method for higher-layer Aurivillius multiferroic ceramics. [ABSTRACT FROM AUTHOR]

We report the magnetic-field-assisted electric-field-controlled domain switching of a magnetic single domain in a multiferroic/magnetoelectric Ni nanochevrons/[Pb(Mg1/3Nb2/3)O3]0.68–[PbTiO3]0.32 (PMN–PT) layered structure. Initially, a magnetic field was applied in the transverse direction across single-domain Ni nanochevrons to transform each of them into a two-domain state. Subsequently, an electric field was applied to the layered structure, exerting the converse magnetoelectric effect to transform/release the two-domain Ni nanochevrons into one of two possible single-domain states. Finally, the experimental results showed that approximately 50% of the single-domain Ni nanochevrons were switched permanently after applying our approach (i.e., the magnetization direction was permanently rotated by 180 degrees). These results mark important advancements for future nanoelectromagnetic systems.

In the present work, Bi0.86Sm0.14FeO3 ceramics with near Pna21 single‐phase structure were obtained by a repeated longtime sintering process, and the dielectric, ferroelectric, and magnetic characteristics were determined together with the magnetoelectric coupling coefficient. The evolution of Pna21 symmetry was revealed by transmission electron microscope analysis, and the ferroelectric transition from Pbnm to Pna21 was determined by differential scanning calorimetry analysis together with the dielectric characterization, and the Curie temperature was determined as 195°C. The saturated polarization–electric field (P–E) hysteresis loop was obtained with Pr = 12.2 μC cm−2, and the unlocking of ferromagnetism was confirmed by the apparent magnetization–magnetic field (M–H) hysteresis loop with Mr = 77.4 emu mol−1. The giant electric field–controlled magnetism was due to the Pna21/R3c field–induced transition, which was confirmed by both structure analysis and theoretical calculation, and the change of remanent magnetization under an electric field was achieved up to 44.8 emu mol−1 (57.9%), which was much bigger than that of rare‐earth (RE)‐substituted BiFeO3 ceramics without optimizing Pna21 phase fraction. The present results might significantly deepen the physical understanding of Pna21 phase and subsequently provide new hints on further enhancing electric field–controlled magnetism in RE‐substituted BiFeO3 multiferroic ceramics. [ABSTRACT FROM AUTHOR]

Novel kind lead-free 0–3 type particulate composites of binary ferroelectric and magnetostrictive phase having molar ratio of (1 − x){0.94Na0.5Bi0.5TiO3 (NBT)-0.06Ba0.85Sr0.15Zr0.1Ti0.9O3 (BSZT)} − (x) Ni0.7Zn0.3Fe2O4 (NZFO) [x = 0, 0.1, 0.3, 0.5 & 1] have been investigated. To probe the magnetoelectric response of the (1 − x)(0.94NBT-0.06BSZT−(x)NZFO composites, structural, morphological and magnetoelectric properties were systematically studied. Scanning electron microscopy (SEM) shows the ferrimagnetic phase (NZFO) distribution in the binary ferroelectric, NB (0.94NBT-0.06BSZT) matrix with different micro-structural symmetry. With increasing ferrimagnetic content, the room temperature dielectric study shows an increase in relative permittivity as well as an increase in dielectric loss. The occurrence of spontaneous polarization in all composites is conclusively demonstrated by polarization with respect to electric field (P–E) loops. The M–H curve at room temperature demonstrates the emergence of ferromagnetic long-range ordering as ferrite concentration increases. The magneto-dielectric and magneto-electric characterization techniques have been used as sensitive probing tools to evaluate the degree of magnetoelectric coupling in (1 − x)(0.94NBT-0.06BSZT − (x)NZFO composites. Magneto-dielectric (MD %) shows the maximum 1.81% change at 1 kHz along with high values of magneto-electric coupling coefficients α ~ 366 μV/cm Oe for 50{0.94NBT-0.06BSZT} − 50NZFO composite. These lead-free environmentally friendly ME particulate composites may provide an opportunity for the miniaturization of future ME devices. [ABSTRACT FROM AUTHOR]

The solid solution of 0.67% Bi0.95La0.05FeO3–0.33% BaTiO3 (BLF–BT) was made by the sol–gel method. The sample's structural, microstructural, and electrical properties were investigated by XRD, SEM, and dielectric measurement, respectively. The BLF–BT shows insulating behavior as revealed from the complex impedance analysis and AC conductivity analysis. The sintered BLF–BT shows relative permittivity of the order of – 106 at high temperatures and follows the Maxwell–Wagner relaxation. Two charge carrier species were responsible for the relaxation process at low and high temperatures. The conduction in the sample is explained with the help of the jump relaxation model (JRM). Room temperature AC conductivity of the BLF–BT samples was observed to be – 10−7 S/cm, lower than that reported in literature. Impedance and modulus analysis was carried out to find out the conduction mechanism. The complex modulus analysis shows almost equal grain and grain boundary capacitances (variation in capacitance is of the order of – 2) in comparison to the resistances (variation in resistance is of the order of – 8). Further, leakage current mechanism is dominated by space charge-limited conduction (SCLC) in our BLF–BT ceramics. [ABSTRACT FROM AUTHOR]

The effect of sintering temperature (Ts) on the phase formation, structural, multiferroic, and magnetoelectric properties of BaTi0.975Fe0.025O3 (BTFO) ceramics has been investigated. The samples have been prepared via a solid-state reaction route and sintered at various temperatures between 1200 °C and 1350 °C. Detailed X-ray diffraction (XRD) analysis confirms a perovskite structure with a tetragonal phase except for the samples sintered at 1350 °C where coexistence of tetragonal and hexagonal phase is observed. The hexagonal phase of the BTFO sample sintered at 1350 °C degrades the electrical properties. All compositions exhibit ferromagnetic behavior, as seen from the M-H curves. Magnetodielectric coefficient (MD) and Magnetoelectric (ME) voltage coefficient α ME have been measured to confirm the intrinsic magnetoelectric behavior. [ABSTRACT FROM AUTHOR]

In this work, we have prepared intergrowth of multiferroic compounds namely Bi4RTi3Fe0.7Co0.3O15-Bi3RTi2Fe0.7Co0.3O12−δ (BRTFCO15-BRTFCO12) (rare earth (R) = Dy, Sm, La) by solid-state reaction method. From the X-ray diffraction Rietveld refinement, the structure of the intergrowths was found to be orthorhombic in which satisfactory fittings establish the existence of three-layered (space group: b 2 c b) and four-layered compounds (space group: A21am). Analysis of magnetic measurements confirmed a larger magnetization for theSm-modified intergrowth compound (BSTFCO15-BSTFCO12) compared to Dy- and La-doped ones. The emergence of higher magnetic properties can be due to distortion in the unit cell when some Bi3+ ions are replaced with the Sm3+, bonding of Fe3+-O-Co3+ as well as a possible mixture of FexCoy-type nanoparticles that are formed generally in the synthesis of intergrowths. The changes in the magnetic state of the Aurivillius intergrowths have been reflected in the magnetoelectric (ME) coupling: higher ME coefficient (~30 mV/Cm-Oe) at lower magnetic fields and is constant up to 3 kOe. The results were corroborated by Raman spectroscopy and variation of temperature with magnetization data. The results revealed that the RE-modified intergrowth route is an effective preparative method for higher-layer Aurivillius multiferroic ceramics.

The present study investigates the optical and magnetodielectric properties of Bi0.9La0.1FeO3 (BLFO) and its composite (0.9) Bi0.9La0.1FeO3/(0.1) La0.7Sr0.3MnO3 (BLFO 10) at room temperature. Crystal structure is confirmed by X-ray diffraction pattern and W–H plots were used to explore the strain developed in the samples. Fourier transform infrared spectra (FTIR) confirmed the presence of metal–oxygen bonds in the samples. The optical absorption spectra indicate an enhancement in the band gap energy of the composite on the addition of La0.7Sr0.3MnO3 (LSMO). The photoluminescence (PL) spectrum reveals that the recombination of electron–hole pairs was suppressed in composites and the chromaticity coordinates were found to be nearly close to the white light region. The multiferroic behavior analyzed through magnetodielectric (MD) analysis shows 4.44% MD effect in BLFO and − 0.45% in BLFO 10 at 1 kHz frequency. By analyzing the thermodynamic equation, the existence of magnetoelectric coupling in BLFO and BLFO 10 was confirmed and magnetodielectric interaction coefficients were also calculated. [ABSTRACT FROM AUTHOR]

Ferroelectric and multiferroic magnetoelectric materials Pb(ZrxTi1-x)O3, BiFeO3–PbTiO3, BiFeO3 PbTiO3, and PbZrO3 with perovskite structure were synthetized, and their optical and structural properties were investigated aiming photovoltaic applications. Single-phase structural properties were observed on the Pb(ZrxTi1-x)O3 and BiFeO3–PbTiO3 systems in their respective regions on phase diagram. Alternative photoacoustic spectroscopy was used to investigate optical properties of the compounds in powder state. Intense absorption was observed in the photoacoustic signal on the visible region of the electromagnetic spectrum. Interesting energy gap was observed in the BiFeO3 (Eg = 1.50 eV) and BiFeO3–PbTiO3 (Eg = 1.53 eV), which are remarkably close to the optimized value (Eg = 1.32 eV) to maximize the photovoltaic efficiency of the theory Shockley-Queisser. The physical mechanisms that distort the structure promote ferroelectricity and remodel the structures of energy bands have been pointed out and discussed. [ABSTRACT FROM AUTHOR]

Multiferroic behaviour in novel kind of ferroelectric (FE)–ferromagnetic (FM) particulate composites of (1−x)PbZr0.95Ti0.05O3(PZT)–(x)Ni0.7Zn0.3Fe2O4 (NZFO) [x = 0.1, 0.2, 0.3 and 0.4] has been studied. The study of FE–FM composites is represented in the context of structural, electrical, magnetic and magnetodielectric properties. X-ray diffraction reveals that both ferroelectric (PZT) and ferrite (NZFO) phases are present in prepared 0–3 type particulate composites. Scanning electron micrographs show the distribution of NZFO in the PZT matrix. Temperature-dependent relative permittivity studies revealed ferroelectric to paraelectric transition at ~ 250 °C. Room-temperature dielectric properties of the system have been studied in a wide range of frequencies (100 Hz to 1 MHz). Polarization versus electric field (P–E) studies at room temperature give conclusive confirmation of the presence of spontaneous polarization in all the composites. Magnetodielectric (MC%) measurements show the maximum 7.74% change at 1 kHz along with high values of magnetoelectric coupling coefficients γ ~ 5.98 × 10–5 (emu/g)−2, χE ~ 53.75 (mV/cm Oe) and χ ~ 16.60 × 10–8 (s/m) for 60PZT–40NZFO composite. [ABSTRACT FROM AUTHOR]

Multiferroic behaviour in novel kind of ferroelectric (FE)–ferromagnetic (FM) particulate composites of (1−x)PbZr0.95Ti0.05O3(PZT)–(x)Ni0.7Zn0.3Fe2O4 (NZFO) [x = 0.1, 0.2, 0.3 and 0.4] has been studied. The study of FE–FM composites is represented in the context of structural, electrical, magnetic and magnetodielectric properties. X-ray diffraction reveals that both ferroelectric (PZT) and ferrite (NZFO) phases are present in prepared 0–3 type particulate composites. Scanning electron micrographs show the distribution of NZFO in the PZT matrix. Temperature-dependent relative permittivity studies revealed ferroelectric to paraelectric transition at ~ 250 °C. Room-temperature dielectric properties of the system have been studied in a wide range of frequencies (100 Hz to 1 MHz). Polarization versus electric field (P–E) studies at room temperature give conclusive confirmation of the presence of spontaneous polarization in all the composites. Magnetodielectric (MC%) measurements show the maximum 7.74% change at 1 kHz along with high values of magnetoelectric coupling coefficients γ ~ 5.98 × 10–5 (emu/g)−2, χE ~ 53.75 (mV/cm Oe) and χ ~ 16.60 × 10–8 (s/m) for 60PZT–40NZFO composite. [ABSTRACT FROM AUTHOR]

In this manuscript the multifunctional multiferroic 0.6BiFeO3-0.4PbTiO3 (BFPT) thin films are presented as an interesting alternative for multifunctional photovoltaic applications. The compound is chemically and structurally stable at high temperatures and consequently reliable to work under difficult operating conditions, such as sunlight radiation. Nanostructured single-phased BFPT thin films were processed and their electric, dielectric, structural, and optics properties were characterized in this work. The films were used as active layers in a heterostructured photovoltaic arrangement, which proves their photovoltaic behavior. Interesting physical properties, as intrinsic photovoltage production (~ 1 mV/cm2) with excitation power (300 W) were associated to the high dielectric constant (> 220 at 1 kHz and room temperature), the existence of long-range electrical conductivity processes, and the presence of two band gap energies (at 3.95 eV and 2.51 eV) in the BFPT compound that enhance the light absorption with consequent photovoltaic generation in the visible light region. [ABSTRACT FROM AUTHOR]

• Enhanced breakdown strength can be achieved in the BLZT/CFO multilayer. • Energy density of 137.6 J/cm3 and efficiency of 76.6 % are achieved in multilayer. • Ferroelectric-domain in BLZT can enhance magnetic-domain in CFO in multilayer. Multifunctional thin films and devices have gained much interest in both scientific and industrial research for futuristic multifunctional micro- and nano-device applications. Here, we report the development of a multi-layer structure based on relaxor-ferroelectric Ba 0.95 La 0.05 Zr 0.4 Ti 0.6 O 3 (BLZT) and ferrimagnetic CoFe 2 O 4 (CFO) ([BLZT/CFO] 3 /BLZT or BLZT/CFO) thin-films on Si substrates for enhanced energy-storage density and magnetic properties. An ultrahigh recoverable energy-storage density (U r) of 137.6 J/cm3 together with an energy efficiency of 76.6 % are achieved for the BLZT/CFO multi-layer, owing to the enhanced breakdown-strength (E BD) of 8.0 MV/cm (BLZT single-layer has an U r value of 84.7 J/cm3 at E BD of 5.5 MV/cm). Moreover, the saturation magnetization of CFO layers in the BLZT/CFO multi-layer significantly increases from 239.2 kA/m to 276.4 kA/m. This enhancement can be attributed to the enlarged magnetic domains in CFO layers, which follow the piezoelectric domain switching in the BLZT layers induced by applying a dc -bias voltage. These remarkable performances indicate that the BLZT/CFO multi-layer is a promising candidate for multifunctional energy storage and magnetoelectric device applications. [ABSTRACT FROM AUTHOR]

The major challenges of developing a robust strain coupling between nanocrystals and a strain medium are addressed by employing a simple self-assembly-based adhesion process that relies on the formation of metal-oxide bonds between Ni nanocrystals and various surfaces. X-ray photoelectron spectroscopy indicates that the adhesion mechanism necessitates high oxidation potential surfaces capable of metal-oxide bond formation. The process is demonstrated to be reversible, using a reducing plasma to induce adhesion in previously unadhered NiO/Ni nanocrystals. Adhesion to the substrate develops interfacial stress in the nanocrystals resulting in a 40 Oe increase in coercivity and a 25 K shift in the blocking temperature. [ABSTRACT FROM AUTHOR]

In this article, we report a systematic study of room-temperature magnetoelectric coupling in 0–3 particulate and 2–2 laminated (bilayer and sandwiched) composite structures of (1 − x)BaTiO3 and (x)NiFe2O4 (x = 0.05, 0.15, 0.25, 0.35 and 0.45). Powder X-ray diffraction and scanning electron microscopic analysis confirm the existence of ferrite (spinel NiFe2O4: NFO) and ferroelectric (tetragonal BaTiO3: BTO) phases in sintered composites without any detectable impurities. Significant variations in electrical polarization and magnetization parameters are observed in composite samples compared to pristine BTO and NFO. The perceived strain-mediated magnetoelectric (ME) coupling is found to be strongly dependent on the relative mass ratio of BTO and NFO in both the particulate and laminated structures. An enhanced magnetoelectric coefficient (αME) of 25.23 mV/cm·Oe is realized for sandwiched-laminated structure of (1 − x)BaTiO3 and (x)NiFe2O4 with x = 0.45 at an applied magnetic field of 1.34 KOe compared to 0–3 particulate and bilayer-laminated composite structures. [ABSTRACT FROM AUTHOR]

Perovskites are among the most famous materials due to their exceptional properties: they present nearly all existing types of interesting properties, in particular as ferroics or multiferroics, they may be insulators, (super)conductors, or semiconductors, magnetoresistant, they are used in numerous devices, they present hundreds of variants and different crystalline phases and phase transitions, and recently appeared as probably the most promising materials for photovoltaics. With a crystal structure characterized by octahedra that share their corners, these materials belong to the wider category of « Framework Structure (FWS) materials » the structure of which is based on units (octahedra, tetrahedra, …) that share some of their corners (or edges) with their neighbours. This particular feature of FWS materials confers to them unique properties. This review volume is constituted of 26 chapters on different aspects, and is divided in two parts, « Fundamental aspects and general properties », and « Elaborated materials and applied properties ». Its main purpose is to attempt to identify the properties common to all members of the vast family of FWS materials, and understand their differences. Besides perovskites, derived compounds as 2D perovskites, Dion-Jacobson, Ruddlesden-Popper, Aurivillius, tungsten-bronzes, and others, are presented, and their preparation and/or properties as single crystals, ceramics, thin films, multilayers, nanomaterials, nanofibers, nanorods, etc, are discussed. We focus on new trends and important recent developments by leaving somewhat aside more classical aspects which can be easily found in older textbooks or review articles. Among most recent applications, this volume focuses on applications related with interactions with other molecules, on photovoltaics, and on memories, with a special attention to perovskite solar cells that have certainly attracted the most attention of researchers in recent years, opening extremely promising routes in photovoltaics. In conclusion, this book presents a collection of texts elucidating various aspects of the relation between structural organization (including dynamical aspects) and singular properties of framework crystals; it proposes a reasonable balance between experimental and theoretical results, and between fundamental aspects and applied properties. This volume can be approached on several levels (each chapter initially assumes that the reader is not a specialist in the subject, and is presented in a pedagogical way) : it is accessible to master or doctoral students, as well as to researchers who want to have informations on recent developments, who will find excellent detailed introductions up to hotsubjects. It may also be used by undergraduate students who should approach given subjects. The volume contains 800 pages written by about 70 authors from different countries, it has an index, and is completed by numerous figures to illustrate the text.

In the present article, a brief introduction about multiferroic composites is provided. Recent advancement in the field of multiferroic composites is discussed by classifying these in bulk composites, thick & thin films and other heterostructures. Research findings of some renowned work are summarized, considering new emerging materials, new methods of synthesis and latest characterization techniques. Further recent applications are discussed along with future challenges of the field. [ABSTRACT FROM AUTHOR]

We review recent developments and advances in the synthesis of thin-film multiferroic and magnetoelectric heterostructures. Driven by the promise of new materials with built-in useful phenomena (i.e., electric field control of ferromagnetism), extensive research has been centered on the search for and characterization of new single-phase multiferroic materials. In this review we provide a brief overview of recent developments in the synthesis of thin film versions of these materials. Advances in modern film growth processes have provided access to high-quality materials for in-depth study. We highlight the use of epitaxial thin-film strain to stabilize metastable phases, drive multiferroic properties, and produce new structures and properties in materials including case studies of EuTiO3 and BiFeO3. © 2012 Elsevier Ltd. All rights reserved.

The potential of nanotechnology in the biomedical field has been crucial for contributing to the possibility of efficiently meeting present necessities with novel materials. Over the last few decades, nanostructures with a core/shell structure have attracted significant attention because of the possibility of changing their physical properties by varying their chemistry and geometry. These structures have become relevant in targeted therapy (drug delivery and treatments to complement chemotherapy and radiotherapy), imaging and in the stimulation of cellular functions. Thus in this paper the current development of core/shell nanostructures is reviewed, emphasizing the physical properties of those that have been proposed as potentially having biomedical applications, which are based in a magnetic behavior or in a mixture of magnetic and electric (multiferroic) phenomena.

BiFeO3-CoFe2O4 (BFO-CFO) vertically aligned nanocomposite (VAN) thin-film promises great potentials for next-generation electronic devices. Its strong magnetoelectric, antiferromagnetic-ferrimagnetic, and structural couplings occur via large interface area interactions across the vertical surface between BFO and CFO phases; this leads to emergent exotic fundamental physics rendering its potential applications for various electronics, such as magnetic sensor, data storages or memory devices, and energy harvesting devices. The distinctive photoactivity of both BFO and CFO phases in the BFO-CFO VAN system also can generate advanced applications as photovoltaic and photocatalytic devices. Furthermore, owing to small overpotential and excellent stability in alkaline media, BFO-CFO nanocomposites becomes the next electrode in electrocatalysis devices. The BFO-CFO VAN also have been exponentially developed having various type of thin-film architectures grown on various substrates. In this present article, we review the current status of the BFO-CFO VAN thin-film and discuss the fundamental understanding as well as the technology involved in developing this material. We also address the challenges that hinder the commercialization of this material and propose some plausible solutions to encourage BFO-CFO VAN-based electronic devices to reach their maturity level. Furthermore, the potential marketability of the BFO-CFO VAN materials and devices for future consumer products is also discussed. [ABSTRACT FROM AUTHOR]

The explosive expansion of multiferroics literature in recent years demonstrates the fast‐growing interest in this field. Although bismuth ferrite is one of the most extensively investigated multiferroic compounds combining magnetoelectric, i.e., antiferromagnetic and ferroelectric features at room temperature, the challenge of producing single‐phase particles remains because the role of multiple synthetic parameters must be unraveled. Herein, the facile synthetic route of aqueous coprecipitation is selected as the first synthetic step, followed by a 700 °C annealing stage to synthesize bismuth ferrite nanoparticles (NPs). This article aims to clarify the influence of ingredients such as precursors: base solution, acid and the Bi/Fe molar ratio, and the role of synthetic parameters such as pH level and reaction temperature toward higher yields of purer crystalline phases. Both structural and magnetic features' performance outline the significance of both stages on forming BiFeO3 single‐phase NPs with the absence of any secondary bismuth oxide phases, a crucial issue for multiferroic features at room temperature. [ABSTRACT FROM AUTHOR]

Magnetoelectric thin-film heterostructures with piezoelectric Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 O 3 and magnetostrictive Co 76 Fe 14 Ni 4 Si 5 B are fabricated. Very high ME coupling coefficients of 8 V/(cm Oe) and ~5.8 V/(cm Oe) are observed for BCZT-MG-BCZT and MG-BCZT-MG trilayers at sub resonance. Micro cantilevers of multilayers with total thickness of 130 µm are also fabricated. The microcantilever of BCZT-MG-BCZT showed an enhanced resonance at a frequency of 840 Hz with MECC as high as ~1457 V/(cm Oe). These structures can be effectively employed as an active component in energy harvesters, sensors, and transducers due to their exceptional ME responses in the resonant and sub-resonant frequencies. Image, graphical abstract [ABSTRACT FROM AUTHOR]

The magnetoelectric ceramics with the composition (1- x)AlFeO 3 - x BaTiO 3 ((1- x)AF- x BT, 0 ≤ x ≤ 0.2) have been synthesized by high energy ball milling method. The BaTiO 3 substitution leads to a crystal structure transformation from orthorhombic Pna 21 to rhombohedral R 3 c. Due to this structural transformation, variations are also induced in the a/b ratio and the phase fraction of the orthorhombic phase. Further, the substitution of AlFeO 3 by BaTiO 3 results in a chemical pressure which induces the ferromagnetic-like behavior and the ME effect in (1- x)AF- x BT ceramics. All the ceramics have shown an unsaturated polarization behavior, and the maximum polarization is attained at x = 0.05. The ME coupling effect has been achieved in all the ceramics, and the optimal ME coefficient is obtained in the 0.95AF-0.05BT ceramic. Besides, it has also been confirmed that the 0.95AF-0.05BT ceramic has shown the ferroelectric relaxor behavior near room temperature. The ME coupling in these ceramics is related to the ferroelectric relaxation, where the polarization of nanoregions is modified by the applied magnetic field. [ABSTRACT FROM AUTHOR]

Multiferroic composite with the general formula (1 − x)BaTiO3−xCoFe2O4 (x = 0.05, 0.15, 0.25, 0.35 and 0.45) has been synthesized by a standard solid-state reaction route. Powder X-ray diffraction analysis confirms the existence of ferrite (spinel CoFe2O4) and ferroelectric (tetragonal BaTiO3) biphase without any impurity phases in the sintered composites. Microstructure of the composite displays two different grain sizes and shapes studied from SEM analysis. The composites show both ferroelectric and ferromagnetic ordering: the saturation magnetization (Ms) and retentivity (Mr) of the composite are improved with the increase in ferrite phase, while leakage current, ferroelectric and dielectric properties of the composites show a drop. Existence of coupling between ferroelectric and ferromagnetic ordering measured through magnetodielectric (MD) and magnetoelectric (ME) studies reveal an increase in % MD and ME coefficients with an increase in ferrite content. An enhanced ME coupling coefficient of 17 mV cm−1 Oe−1 has been realized at a dc magnetic field of 5 kOe with a ac frequency of 50 Hz in (1 − x)BaTiO3−xCoFe2O4 (x = 0.45) composite. [ABSTRACT FROM AUTHOR]

A series of (1- x)BaFe 12 O 19 - x BiFeO 3 (x = 0.0, 0.25, 0.50, 0.75 and 1.0) multiferroic ceramic composites have been synthesized using standard mechano-chemical activation technique. Room temperature magnetic hysteresis loop measurement indicates that the ferrimagnetic loop of the composites is strongly influenced by BaFe 12 O 19 phase and therefore, a highly saturated magnetic characteristic has been observed in composites as compared to pure BiFeO 3. Composites show a significant enhancement in ferroelectric properties, which may be attributed to the decrease in leakage current caused by the BiFeO 3 addition. The variations of magnetic and magnetoelectric characteristics were analyzed with the help of various conduction mechanism occurring in these materials. An improved magnetoelectric coupling coefficient of up to 11.9 mV/(Oe·cm) was obtained for the sample with x = 0.50, which is nearly 1.5 times higher than the pure BiFeO 3 ceramic. These results demonstrate that the substitution of BiFeO 3 in an appropriate proportion can be a feasible way to improve the multiferroic properties of BaFe 12 O 19. • BaFe 12 O 19 /BiFeO 3 composites were synthesized using the mechano-chemical activation technique. • Rietveld analysis confirms the formation of diphasic multiferroic composites. • Composites have shown enhanced electrical properties compared to pristine BaFe 12 O 19. • 0.5BaFe 12 O 19 -0.5BiFeO 3 shows optimum magnetoelectric properties, which may be attributed to the presence of optimum heterogeneity in the material. [ABSTRACT FROM AUTHOR]

Magnetoelectric composites with composition (x)Ni 0.5 Zn 0.5 Fe 2 O 4 + (1-x)PbZr 0.8 Ti 0.2 O 3 (PZT- Lead Zirconate Titanate) in which x varies as 0.0, 0.15, 0.30, 0.45 and 1.0 mol % were prepared by the conventional double sintering ceramic technique. The phase analysis was carried out using X-ray diffraction technique, which confirms the absence of any intermediate phase present in the composites. Scanning electron micrographs (SEM) were taken to understand the surface morphology of the samples. The DC resistivity was measured as a function of temperature. The variation of dielectric constant (ε′) and loss tangent (tanδ) in the frequency range 20 Hz to 1 MHz was studied. The conduction phenomenon was explained on the basis of small polaron hopping model. The confirmation of this phenomenon was made with the help of AC conductivity measurements. [ABSTRACT FROM AUTHOR]

Multiferroic magnetoelectric (ME) materials with the capability of coupling magnetization and electric polarization have been providing diverse routes towards functional devices and thus attracting ever-increasing attention. The typical device applications include sensors, energy harvesters, magnetoelectric random access memories, tunable microwave devices and ME antennas etc. Among those application scenarios, ME sensors are specifically focused in this review article. We begin with an introduction of materials development and then recent advances in ME sensors are overviewed. Engineering applications of ME sensors are followed and typical scenarios are presented. Finally, several remaining challenges and future directions from the perspective of sensor designs and real applications are included.

A band‐stop filter with dual resonators of yttrium iron garnet (YIG) and lead zirconate titanate (PZT) operating in the S‐ and C‐bands was designed and characterized. Such multiferroic composite resonators allow for mechanical strain mediated control of the ferromagnetic resonance frequency of YIG via a DC voltage applied to PZT. The electric field E‐tuning of the central frequency of the individual resonators by 65‐70 MHz has been utilized for the control of the isolation characteristics by 17 dB and to achieve a maximum transmission loss of 37 dB. The 3 dB‐width of the stop‐band can also be tuned between 40 and 100% when a DC voltage is applied to only one of the two resonators. Such E‐tuning of filter characteristics are of interest for applications in communication systems. [ABSTRACT FROM AUTHOR]

Abstract The search for lead-free high performance magnetoelectric multiferroic materials at room temperature continues to be stimulated from the perspective of designing environmentally friendly multifunctional devices. In this context, lead-free composite thin films consisting of Ba 1-x Ca x Zr 0.10 Ti 0.90 O 3 (BCZT, x = 0, 0.10 and 0.15) as the ferroelectric/piezoelectric phase and Ni 0.92 (Cu 0.05 Co 0.03)Fe 2 O 4 (NCCFO) as the ferromagnetic/magnetostrictive component have been grown on Pt/TiO 2 /SiO 2 /Si substrates via chemical solution spin-coating method. The phase and structural evolutions of two distinct pure phases of as grown NCCFO/BCZT composite films were confirmed using X-ray diffractrometry (XRD) and field emission scanning electron microscopy (FE-SEM). The multiferroic, magneto-dielectric and magnetoelectric properties of the NCCFO/BCZT composite films have been investigated. Moreover, significant enhancement of multiferroic properties and magnetoelectric effect was observed in these composite films when compared to those reported recently for other lead-free BCZT based multiferroic composites. The magnetic studies demonstrate that the NCCFO/Ba 0.90 Ca 0.10 Zr 0.10 Ti 0.90 O 3 (NCCFO/BCZT10) composite film exhibits a large saturation and remnant magnetization of M s ∼ 346.2 emu/cm3 and M r ∼ 73.5 emu/cm3 respectively having a coercive field of H c ∼ 73.5 Oe. The NCCFO/BCZT10 composite film also exhibits good ferroelectric properties with saturation polarization P s ∼26.7 μC/cm2, remnant polarization P r ∼8.9 μC/cm2 and coercive field E c ∼82.7 kV/cm. The observed magneto-dielectric effect is of two orders higher than those reported for other lead-free multiferroic composites. A maximum magnetoelectric voltage co-efficient of α ME ∼22.4 mVcm−1Oe−1 is obtained for the NCCFO/BCZT10 composite film. The observed results suggest that the NCCFO/BCZT composite films are potential lead-free multiferroic systems at room temperature. Graphical abstract Image 103778 Highlights • Deposition of lead-free Ni 0.92 (Cu 0.05 Co 0.03)Fe 2 O 4 /(Ba, Ca)(Zr, Ti)O 3 composite thin films by chemical solution method. • The structural, multiferroic, magneto-dielectric and magnetoelectric properties. • Enhanced multiferroic, magneto-dielectric and magnetoelectric Properties. • A correlation between structural, magneto-dielectric and multiferroic properties. • Potential lead-free multiferroic systems at room temperature. [ABSTRACT FROM AUTHOR]

Abstract In this paper, we report the influence of Ni doping on the structural, electrical, magnetic and magnetoelectric properties of BaTiO 3 (BTO) ceramics. X-ray diffraction (XRD) analysis indicates a phase transition from tetragonal to hexagonal at x = 2.5 mol%. Further, XRD data has been refined using Rietveld method to extract the phase formation, lattice parameters, and the phase fraction of BaTi 1-x Ni x O 3 (BTNO) (0 ≤ x ≤ 10 mol %) ceramics. The ferroelectric polarization decreases with Ni doping concentration. The relative permittivity of BTNO compositions decreases while the corresponding dielectric loss increases with Ni doping concentration. Room temperature magnetic hysteresis (M-H) loop of all BTNO samples exhibit ferromagnetic nature with a saturated loop except for x = 2.5 mol% Ni doping concentration. At x = 2.5 mol% Ni doping concentration, a small amount of diamagnetism is observed at higher fields along with ferromagnetism. The origin of ferromagnetism is due to the F- center exchange interaction via oxygen vacancies. The highest remnant magnetization (M r) is 11.76 memu/g for x = 10 mol%. The Magnetodielectric coefficient (MD) and magnetoelectric coefficient (ME) gradually increases with increasing Ni doping concentration, and are 1.72% and 4.51 mV cm − 1 Oe − 1 respectively for x = 10 mol%. [ABSTRACT FROM AUTHOR]

The potential of nanotechnology in the biomedical field has been crucial for contributing to the possibility of efficiently meeting present necessities with novel materials. Over the last few decades, nanostructures with a core/shell structure have attracted significant attention because of the possibility of changing their physical properties by varying their chemistry and geometry. These structures have become relevant in targeted therapy (drug delivery and treatments to complement chemotherapy and radiotherapy), imaging and in the stimulation of cellular functions. Thus in this paper the current development of core/shell nanostructures is reviewed, emphasizing the physical properties of those that have been proposed as potentially having biomedical applications, which are based in a magnetic behavior or in a mixture of magnetic and electric (multiferroic) phenomena. [ABSTRACT FROM AUTHOR]

• FTIR confirms the vibrational bonds of coexisting phases. • The P-E loops get fatter with the addition of ferrites indicating the para to ferroelectric transition. • The high dielectric constant with low loss indicates conductive behavior. • Magnetically stable over a wide frequency range (100 kHz–100 MHz). • (0.1) Ba 0.5 La 0.5 TiO 3 + (0.9) Co 0.8 Zn 0.2 Fe 2 O 4 can be suitable for magnetic sensors. The solid-state reaction method is followed to fabricate multiferroic particulate composites, (1- x) Ba 0.5 La 0.5 TiO 3 + (x) Co 0.8 Zn 0.2 Fe 2 O 4 (x = 0.0, 0.1, 0.3, 0.5, 0.7, 0.9, 1.0). X-ray diffraction patterns reflect the coexistence of the constituent phases in the composites after 4 h of sintering at 1200 °C. Cubic structures of both ferroelectric and ferrite phases confirmed from Rietveld refinement are distinctively dominant. The Fourier Transform Infrared (FTIR) spectrum confirms the characteristic vibration bonds of Co-ferrite, Zn-ferrite, and Ti-O. A slight variation of lattice parameters is observed with the increasing ferrite concentration. Bulk density reveals the inverse behavior of theoretical density. The obtained average grain size varies from 1.308 µm to 3.046 µm. All the composites have good ferromagnetic properties confirmed by hysteresis loops. The coercive field at x = 0.5 is 297.98 Oe, dramatically higher than other concentrations. The real part of permeability (μ i ′) gradually increases with increasing ferrite content as per the sum rule of the mixture. To investigate the electric properties of the samples, the dielectric constant ( ε ′) and loss tangent (tan δ) are measured in the frequency range of 100 Hz to 100 MHz. The dielectric constant ( ε ′) decreases at first and after x = 0.3, it begins to increase with further addition of the ferrite phase. The maximum dielectric constant ( ε ′) is 1092.08 at x = 0.9. The dielectric constant ( ε ′) and loss tangent (tan δ) display Maxwell-Wagner interfacial polarization and reduce from low to high frequency. All of the samples appear to be highly resistive indicating the reduction of leakage current. The dielectric constant ( ε ′) and resistivity show the opposite trend. P-E hysteresis loops indicate para -electric to ferroelectric transition. [ABSTRACT FROM AUTHOR]

Magnetoelectric (ME) materials composed of magnetostrictive and piezoelectric phases have been the subject of decades of research due to their versatility and unique capability to couple the magnetic and electric properties of the matter. While these materials are often studied from a fundamental point of view, the 4.0 revolution (automation of traditional manufacturing and industrial practices, using modern smart technology) and the Internet of Things (IoT) context allows the perfect conditions for this type of materials being effectively/finally implemented in a variety of advanced applications. This review starts in the era of Rontgen and Curie and ends up in the present day, highlighting challenges/directions for the time to come. The main materials, configurations, ME coefficients, and processing techniques are reported.

Magnetic sensors are mandatory in a broad range of applications nowadays, being the increasing interest on such sensors mainly driven by the growing demand of materials required by Industry 4.0 and the Internet of Things concept. Optimized power consumption, reliability, flexibility, versatility, lightweight and low-temperature fabrication are some of the technological requirements in which the scientific community is focusing efforts. Aiming to positively respond to those challenges, this work reports magnetic proximity sensors based on magnetoelectric (ME) polyvinylidene fluoride (PVDF)/Metglas composites and an excitation-printed coil. The proposed magnetic proximity sensor shows a maximum resonant ME coefficient (α) of 50.2 Vcm−1 Oe−1, an AC linear response (R2 = 0.997) and a maximum voltage output of 362 mV, which suggests suitability for proximity-sensing applications in the areas of aerospace, automotive, positioning, machine safety, recreation and advertising panels, among others.

Combining various (multi-)ferroic materials into heterostructures is a promising route to enhance their inherent properties, such as the magnetoelectric coupling in BiFeO3 thin films. We have previously reported on the up-to-tenfold increase of the magnetoelectric voltage coefficient α ME in BaTiO3-BiFeO3 multilayers relative to BiFeO3 single layers. Unraveling the origin and mechanism of this enhanced effect is a prerequisite to designing new materials for the application of magnetoelectric devices. By careful variations in the multilayer design we now present an evaluation of the influences of the BaTiO3-BiFeO3 thickness ratio, oxygen pressure during deposition, and double layer thickness. Our findings suggest an interface driven effect at the core of the magnetoelectric coupling effect in our multilayers superimposed on the inherent magnetoelectric coupling of BiFeO3 thin films, which leads to a giant α ME coefficient of 480 Vc m − 1 Oe − 1 for a 16 × (BaTiO3-BiFeO3) superlattice with a 4.8 nm double layer periodicity.

Lead-free multiferroic composites with enhanced magnetoelectric properties and sensitivity have potential for various multifunctional devices. The magnetoelectric behaviour of CoFe 2 O 4 -(Ba 0.85 Ca 0.15 ) (Zr 0.1 Ti 0.9 )O 3 , (CFO-BCZT) and substituted CFO-BCZT laminate composites prepared by epoxy bonding are investigated in this study. Magnetostrictive CoFe 2 O 4 (CFO) substituted with Ti (CTFO) resulted in a very high piezo-magnetic coefficient (q) of ∼290 × 10 −9  Oe −1 . Lead free piezoelectric (Ba 0.85 Ca 0.15 ) (Zr 0.1 Ti 0.9 )O 3 [BCZT] substituted with Ce 4+ (BCZCT) showed improved piezoelectric coefficients of d 33 ∼ 675 pC/N and g 33 ∼13 mV m/N. Two new trilayer multiferroic laminates were developed with a (2-2) composite connectivity by combining the pure and substituted ferroic phases. Magnetostrictive, ferroelectric, piezoelectric and magnetoelectric properties of CFO-BCZT and CTFO-BCZCT laminate composites were measured and compared in here. CTFO-BCZCT composite exhibited a large magnetoelectric response with a high ME coefficient (α ME ) of ∼950 mV/cm.Oe and also showed an improved magnetoelectric sensitivity at lower magnetic fields, making it a potential lead-free material for magnetoelectric sensing applications. [ABSTRACT FROM AUTHOR]

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)Ba 0.85 Ca 0.15 Ti 0.90 Zr 0.10 O 3 -(x)CoFe 2 O 4 (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 P s  ∼ 5.1 µC/cm 2 , P r  ∼ 1.4 µC/cm 2 and E c  ∼ 11.6 kV/cm respectively. The BCTZ-CFO composite with 90 wt% of CFO incorporation exhibits improved ferromagnetic properties with M s  ∼ 32 emu/g, M r  ∼ 11.7 emu/g and H c  ∼ 504 Oe. Mӧssbauer spectra analysis show two sets of six-line hyperfine patterns for BCTZ-CFO composites, indicating the presence of Fe 3+ 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. [ABSTRACT FROM AUTHOR]