Improvement of the magnetic properties of highly porous open-celled magnets

In the present study, we have investigated the influence of B₂O₃ addition on structural and magnetic properties of hard magnetic BaFe₁₂O₁₉ foams. In the presence of B₂O₃ open-celled foams were successfully fabricated at a calcination temperature of 1300 °C. Magnetization values have been improved by 50% with B₂O₃-addition. Remanence magnetization (M_R), specific magnetization at 1.5 T (M_S) and coercive field (H_c) values were obtained to be 32.7 emu/g, 63.0 emu/g and 2100 Oe, respectively for the 0.5 wt% B₂O₃ containing foams having 30 pores/in. Foams with these magnetic properties have the potential to be used in different areas of technology as permanently magnetic materials.     

Structural,magnetic and dielectric behavior of Mg1−xCaxNiyFe2−yO4 nano-ferrites synthesized by the micro-emulsion method

Ca–Ni co-substituted samples of nanocrystalline spinel ferrites with chemical formula Mg_1−xCa_xNi_yFe_2−y O₄ (x=0.0–0.6, y=0.0–1.2) were synthesized by the micro-emulsion method and were annealed at 700 °C for 7 h. The synthesized samples were characterized by x-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, vibrating sample magnetometry (VSM) and dielectric measurements. The XRD and FTIR analysis reveals that single phase samples can be achieved by substituting Ca and Ni ions at Mg and Fe sites respectively in cubic spinel nano-ferrites. The crystallite size of the synthesized samples was found in the range 29–45 nm. The saturation magnetization (M_s) increases from 9.84 to 24.99 emu/g up to x=0.2, y=0.4 and then decreases, while the coercivity (H_c) increases continuously from 94 to 153 Oe with the increase in dopants concentration. The dielectric properties of these nano materials were also studied at room temperature in the frequency range 100 MHz to 3 GHz. The dielectric parameters were found to decrease with the increased Ca–Ni concentration. Further the peaking behavior was observed beyond 1.5 GHz. The frequency dependent dielectric properties of all the samples have been explained qualitatively on the basis of the Maxwell–Wagner two-layer model according to Koop's phenomenological theory. The enhanced magnetic parameters and reduced dielectric properties make the synthesized materials suitable for switching and high frequency applications, respectively.     

Structural,magnetic, vibrational and impedance properties of Pr and Ti codoped BiFeO3 multiferroic ceramics

Single-phase (Bi_1−xPr_x)(Fe_1−xTi_x)O₃ ceramics (x=0.03, 0.06, and 0.10 as BPFT-3, BPFT-6 and BPFT-10, respectively) were synthesized by conventional solid state reaction method. The effect of varying Pr and Ti codoping concentration on the structural, magnetic, dielectric and optical properties of the BPFT ceramics have been investigated. X-ray diffraction indicated pure rhombohedral phase formation for BPFT-3 and BPFT-6 ceramics, however, a structural phase transition from a rhombohedral to an orthorhombic phase has been observed for BPFT-10 ceramic. The maximum remnant magnetization of 0.1824 emu/g has been observed in BPFT-6. With increasing codoping concentration the room temperature dielectric measurements showed enhancement in dielectric properties with reduced dielectric loss. UV–vis diffuse reflectance spectra demonstrated the strong absorption of light in the visible region for a band gap variation 2.31–2.34 eV. Infrared spectroscopy indicated the shifting of Bi/Pr–O and Fe/Ti–O bonds vibrations and change in Fe/Ti–O bond lengths. Decrease in the conductivity on increasing Pr and Ti concentration in BFO is attributed to an enhancement in the barrier properties leading to suppression of lattice conduction path arising due to lattice distortion as confirmed from impedance analysis.     

The role of Eu2O3 and CeO2 on the phase formation,infrared emission and magnetic properties of Co0.6Zn0.4Fe2O4 ceramics by a solvothermal method

Nanosized Eu₂O₃ and CeO₂ co-addition CoZn ceramics have been achieved via a hydrothermal method by adjusting the mol ratios of Eu and Ce. The as-prepared samples were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared (FTIR), Vibrating sample magnetometer (VSM) and Infrared emission measurement (IRE-2). The particle morphologies of the as-prepared samples evolve from spherical, to self-assembled nanoparticles, and irregular nanoparticles when the mol ratios (x) of Eu and Ce was changed from 0:10 to 10:0. Correspondingly, the main phases of the as-prepared samples change from both cubic spinel CoFe₂O₄ and CeO₂, pure cubic cerianite CeO₂, to amorphous. Meanwhile, the as-prepared samples appear transformed from a ferromagnetic behavior with a saturation magnetization 66.4 emu/g to a paramagnetic behavior with a saturation magnetization of 0.55 emu/g at turning point x=3.5:6.5. While the infrared emissivity is increasing as the x from 0:10 to 3.5:6.5, reach the maximum at 3.6:6.4, and then remain stable when further increasing x till 10:0. Those may be due to the amorphous tendency rising and the particle sizes gradual decreasing with x increasing from 0:10 to 10:0. What is more important is that the solvothermal method is proved to be an efficient way to prepare CoZn nano-ceramics in this study which may open new pathways to magnetic and far infrared therapy.     

Magnetic and magnetoresistive properties of La0.65−xEuxSr0.35MnO3

Eu-doped perovskites La_0.65−xEu_xSr_0.35MnO₃ (0.05 ≤ x ≤ 0.30) were synthesized by sol–gel method using citric acid and characterized by X-ray diffraction, magnetization, resistivity and magnetoresistance (MR) experiments. All samples had a single hexagonal perovskite structure. As x increased from 0.05 to 0.30, the Curie temperature T_C for the samples decreased from 352 to 242 K. It was found that two transition points appeared when the resistivity changed with increasing temperature, and upon an application of a magnetic field of 20 kOe the maximum magnetoresistivity of 18% for the La_0.65−xEu_xSr_0.35MnO₃ with x = 0.20 was obtained at room temperature 300 K. The mechanism of the transitions for the samples was explored.     

Mechanosynthesis,crystal structure and magnetic characterization of M-type SrFe12O19

M-type strontium hexaferrite was prepared by mechanosynthesis using high-energy ball milling. The influence of milling parameters, hematite excess and annealing temperature on magnetic properties of SrFe₁₂O₁₉ were investigated. Commercial iron and strontium oxides were used as starting materials. It was found that mechanical milling followed by an annealing treatment at low temperature (700 °C) promotes the complete structural transformation to Sr-hexaferrite phase. For samples annealed at temperatures from 700 to 1000 °C, saturation magnetization values (M_s) are more sensitive to annealing temperature than coercivity values (H_c). The maximum M_s of 60 emu/g and H_c of 5.2 kOe were obtained in mixtures of powders milled for 5 h and subsequently annealed at 700 °C. An increase in the annealing temperature produces negligible changes in magnetic saturation and coercivity. An excess of hematite as a second phase produces a slight decrease in the saturation magnetization but leads to a significant increase in coercive field, reaching 6.6 kOe.     

A novel bithiazole oligomer containing C60 and its ferro-complexes: syntheses and magnetic properties

A novel bithiazole oligomer (PCBT) was synthesized from C₆₀ and the diazo salt of 2,2′-diamino-4,4′-bithiazole (DABT). Its ferro-complex (PCBT-Fe²⁺) was prepared from PCBT and FeSO₄ in DMSO solution under a purified nitrogen atmosphere. The magnetic behavior of PCBT and PCBT-Fe²⁺ was measured as a function of magnetic field strength (0-60 kOe) at 5 K and as a function of temperature (5-300 K) at a magnetic field strength of 30 kOe. PCBT-Fe²⁺ complex exhibits a hysteresis cycle at 5 K, the observed coercive field (H_C) and remnant magnetization (M_r) are 690 Oe and 0.12 emu/g, respectively. The results show that PCBT is an anti-ferromagnet and its Fe²⁺-complex is a soft ferromagnet.     

Magnetic properties of carbon nano-particles produced by a pulsed arc submerged in ethanol

Carbon powder was produced by a pulsed arc ignited between two carbon electrodes submerged in ethanol, and was comprised of both micro- and nano-particles. The measured magnetic properties of the mixed “raw” powder at 20 and 300 K were: saturation magnetization M_s ∼ 0.90-0.93 emu/g, residual magnetization M_r = 0.022 and 0.018 emu/g, and coercive force H_c = 11 and 8 Oe, respectively. The data lead to conclusion that the powder consisted of ferromagnetic particles with a critical temperature much higher than 300 K. Magnetic particles in solution were separated by means of bio-ferrography. It was found that the magnetically separated particles included chains of ∼30-50 nm diameter spheres, and nanotubes and nanorods with lengths of 50-250 nm and diameters of 20-30 nm. In contrast, the residual particles which passed through the bio-ferrograph consisted of 1 μm and larger micro-particles, and nano-particles without any definite shape.     

Sol–gel auto combustion synthesis of CoFe2O4/1-methyl-2-pyrrolidone nanocomposite: Its magnetic characterization

A magnetic nanocomposite was generated by the sol–gel auto-combustion method in the presence of 1-methyl-2-pyrrolidone, a functional solvent. The temperature-dependent magnetic properties of the CoFe₂O₄ nanoparticles have been extensively studied in the temperature range of 10–400 K and magnetic fields up to 80 kOe. Zero field cooled (ZFC) and field cooled (FC) curves indicate that the blocking temperature (T_B) of the CoFe₂O₄ nanoparticles is above 400 K. It was found from M–H curves that the low temperature saturation magnetization values are higher than bulk value of CoFe₂O₄. The saturation magnetization (M_s), remanence magnetization (M_r), reduced remanent magnetization (M_r/M_s) and coercive field (H_c) values decrease with increasing temperature. The M_r/M_s value of 0.75 at 10 K indicates that the CoFe₂O₄ nanoparticles used in this work have, as expected, cubic magnetocrystalline anisotropy according to the Stoner–Wohlfarth model. T^1/2 dependence of the coercive field was observed in the temperature range of 10–400 K according to Kneller's law. The extrapolated T_B and the zero-temperature coercive field values calculated according to Kneller's law are almost 427 K and 13.2 kOe, respectively. The room temperature H_c value is higher than that of the previously reported room temperature bulk values. The effective magnetic anisotropy constant (K_eff) was calculated as about 0.23×10⁶ erg/cm³ which is lower than that of the bulk value obtained due to disordered surface spins.     

Synthesis of Co-Zr doped nanocrystalline strontium hexaferrites by sol-gel auto-combustion route using sucrose as fuel and study of their structural,magnetic and electrical properties

Sol-gel auto-combustion route using sucrose as fuel has been employed to synthesize nanocrystalline particles of SrZr_xCo_xFe_(12−2x)O₁₉ (0.0≤ x ≤1.0). The characterization of these materials has been done by TGA-DTA, FT-IR, XRD and EDS. SEM and TEM techniques have been used to study the structure and morphology. Magnetic properties have been investigated by VSM and Mössbauer spectroscopy (MS). The influence of calcination temperature on morphology and magnetic properties of samples is studied in a wide temperature range of 500–1100 °C. XRD analysis indicates the formation of pure single phase hexagonal ferrites at 900 °C. The crystallite size calculated using Scherrer equation lies in a narrow range of 21–33 nm. The crystallite size is small enough to obtain a suitable signal to noise ratio in high density recording medium. Substitution of Zr and Co for Fe has been found to have a profound effect on the structural, magnetic and electrical properties. Upon substitution saturation magnetization (M_S) first increases from 62.67 emu/g to 64.84 emu/g (up to x=0.4) followed by a decrease to 49.71 emu/g at x=1.0. There is a slow fall in coercivity (H_C) from 5785.74 (x=0.0) to 1796.51 Oe (x=1.0). Dielectric constant, dielectric loss tangent and AC conductivity in the frequency range 20 Hz to 120 MHz have been studied for all the compositions (x=0–1.0). The composition and frequency dependence of these dielectric parameters has been qualitatively explained.     

X-ray phase,structural, dielectric and magnetic studying of BiFe1-х(M1/2Ti1/2)хO3 (M = Co,Ni, Zn, х = 0–0.11) multiferroics

Perovskite-like rhombohedral distorted solid solutions of BiFe_1-х(M_1/2Ti_1/2)_хO₃ (M = Co, Ni, Zn, x = 0–0.11) were obtained by solid-phase synthesis. An indicator of the solid solution formation is the change of unit cells parameters, that corresponds to the ionic radii of mixed cations (M1/2Ti1/2)3+ (M = Co, Ni, Zn. Solid solutions of BiFe_1-х(M_1/2Ti_1/2)_хO₃ (M = Co, Ni), in contrast to BiFe_1-x(Zn_1/2Ti_1/2)_xO₃ demonstrate ferromagnetic hysteresis pels at room temperature. The x growth in the range from 0.01 to 0.11 for the BiFe_1-х(M_1/2Ti_1/2)_хO₃ system leads to, the saturation magnetization M_S and the remanent magnetization M_R increase from ∼0.1 and ∼2.4⋅10⁻³ emu/g to ∼0.4 and ∼0.038 emu/g respectively. In the same time the coercive force H_c decreases from ∼120 to ∼80 Oe. For the BiFe_1-х(Co_1/2Ti_1/2)_хO₃ system, a noticeably higher magnetic properties with a more complex dependence on x are observed. The maximum parameter values are observed at x = 0.04–0.05: M_S = 0.83 and M_R = 0.24 emu/g, H_c = 1.8 kOe. It is suggested that the detected anomalies of Co-containing solid solutions behavior are related to the one-ionic magnetocrystalline anisotropy of Co²⁺ cations. The BiFe_1-х(M_1/2Ti_1/2)_хO₃ (M = Co, Ni) samples demonstrate piezoelectric constant d₃₃ up to 7 pC/N. Due to the set of properties the materials obtained can be classified as high-temperature multiferroics.     

Magnetic and thermal expansion properties of chromium-substituted lithium ferrite

The structure, magnetic, and thermal expansion properties of chromium-substituted lithium ferrite have been investigated. The lattice constant (Å) decreases linearly as a (x) = 8.32366 − 0.04338x for Li_0.5Fe_2.5−xCr_xO₄ (x = 0.0–1.0). When increasing Cr content, the initial permeability decreased gradually. The average thermal expansion coefficient of Li_0.5Fe_2.5−xCr_xO₄ (x = 0.0–1.0) varied from 15.34 to 17.77 ppm/°C, with increasing Cr content, the average thermal expansion coefficient decreased. The average thermal expansion coefficient (ppm/°C) in the range of 25–850 °C give the polynomial correlation as follows, TEC (x) = 1 7.775 − 0.216x − 0.723x² − 1.493x³ for Li_0.5Fe_2.5−xCr_xO₄ (x = 0.0–1.0).     

One-step synthesis of Ni0.5Zn0.5Fe2O4 fine-patterned films via photosensitive sol–gel route

Ni_1−xZn_xFe₂O₄ (NZFO) (x=0.0–0.7) films were prepared by a photosensitive sol–gel route utilizing nickel acetate, zinc acetate and ferric nitrate as starting materials. The saturation magnetization of the NZFO film showed a parabolic tendency with Zn substitution. For Zn substitution of 0.5, the saturation magnetization reached the maximum value of 683 emu/cm³ with a relative low coercivity of 56 Oe at room temperature. The phase constituents and surface morphology of the films were characterized by X-ray diffractometer (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Through a direct patterning process, a fine-patterned Ni_0.5Zn_0.5Fe₂O₄ film was obtained by a photochemical reaction between the chelated complexes and UV light.     

Structural, morphological, magnetic and optical properties of chromium substituted strontium ferrites, SrCrxFe12 − xO19 (x = 0.5, 1.0, 1.5, 2.0 and 2.5) annealed with potassium halides

Chromium substituted strontium ferrites SrCr_xFe_12 − xO₁₉ (x = 0.5, 1.0, 1.5, 2.0 and 2.5) have been synthesized via sol gel method and the dry gels obtained have been annealed with various inorganic template agents (KCl, KBr and KI). The powder X ray diffraction studies reveal a crystallite size of ~ 40-45 nm. The use of KCl as inorganic template agent leads to an increase in the crystallite size. This may be attributed to the fact that the coordination ability of Cl⁻ is maximum due to its larger charge to size ratio, which promotes crystal growth in one dimension leading to needle-like morphology. On the other hand, KI undergoes sublimation to form I₂ which gets entrapped in the strontium ferrite crystal leading to a bubble-like morphology. A systematic change in the lattice constants, a and c, is not observed because the radius of Cr³⁺ ion (0.63 Å) is similar to that of Fe³⁺ ion (0.64 Å). The saturation magnetization decreases with increase in the chromium concentration from 43.03 emu/g to 17.40 emu/g due to the substitution of Fe³⁺ ions by less magnetic Cr³⁺ ions in 2a and 12k sites of the lattice. The coercivity decreases with increase in the chromium concentration due to decrease in magnetocrystalline anisotropy. In the presence of KCl and KBr, both saturation magnetization and coercivity increase and the saturation magnetization has the maximum value in case of samples annealed with KBr. However, with KI, the values of both saturation magnetization and coercivity decrease sharply which may be due to lower crystallinity due to bubble-like morphology because of the decomposition of KI to I₂. The energy band gap for all the ferrite compositions is found to be ~ 2.2 eV and its value increases in the samples annealed with KI.     

Magnetic and Optical Properties of Mn1−xZnxFe2O4 Nanoparticles

Mn_1?xZn_xFe₂O₄ (x = 0.0?1.0) NPs (MZF NPs) were synthesized by a citric acid assisted sol–gel process. MZF NPs show superparamagnetic characteristics at room temperature. Saturation magnetization (M_s) of MnFe₂O₄ NPs is 70.52 emu/g is very close to the bulk saturation magnetization value of 80 emu/g. The observed M_s = 35.90 emu/g value for ZnFe₂O₄ particles is much greater than the bulk M_s value of 5 emu/g. This case is attributed to cation distribution change from normal spinel to mixed structure. The small M_r/M_s ratios (the maximum 0.147) specify uniaxial anisotropy in the Mn_1-xZn_xFe₂O₄ NPs. The average crystallite diameter (D _mag) was evaluated from magnetic analyses. The obtained D _mag values are between 27.67 and 33.60 nm and this range is in great accordance with the results calculated from XRD measurements. Among the NPs, the samples with more zinc content show higher diffuse reflectance. The optical direct band gap of MZF NPs is found to decrease from 2.1 to 1.90 eV as the zinc content rises.     

Phase equilibria and dielectric properties of Bi3+(5/2)xMg2−xNb3–(3/2)xO14−x cubic pyrochlores

Subsolidus pyrochlores with the proposed formula, Bi_3+(5/2)xMg_2−xNb_3−(3/2)xO_14−x (0.14≤x≤0.22) were successfully synthesised at the firing temperature of 1025 °C using conventional solid-state reaction. The excess Bi³⁺ charge was offset by removal of relative proportion of Mg²⁺ and Nb⁵⁺ together with creation of oxygen non-stoichiometry in order to preserve electroneutrality of the system. These samples were crystallised in cubic structure with space group of Fd3m, No. 227 and their refined lattice parameters were in the range of 10.5706 (3)–10.5797 (7) Å. The surface morphologies of the samples as confirmed by scanning electron microscopy analysis were of irregular shaped grains while their crystallite sizes of ~30–85 nm were calculated using the Scherrer equation and the Williamson–Hall method. No thermal event was discernable indicating these pyrochlores were thermally stable within a studied temperature range of ~30–1000 °C. The recorded dielectric constants of Bi_3+(5/2)xMg_2−xNb_3−(3/2)xO_14−x (0.14≤x≤0.22) subsolidus pyrochlores were generally above ~160 and their dielectric losses were in the order of 10⁻⁴–10⁻³ at the frequency of 1 MHz and temperature of ~30 °C. Meanwhile, these ceramic samples also exhibited negative temperature coefficient of relative permittivity between −528 and −742 ppm/°C in the temperature range of ~30–300 °C.     

Synthesis of MnFe2O4 nanocrystals by wet-milling under atmospheric conditions

This work reports an original method for synthesis of well-crystallized manganese ferrite (MnFe₂O₄) nanoparticles via a high energy wet milling technique under atmospheric conditions, starting from metallic Mn and Fe powders in the presence of distilled water. The effects of milling conditions on the formation and magnetic properties of MnFe₂O₄ nanoparticles were investigated in detail. Fully stoichiometric MnFe₂O₄ nanocrystals with an average crystallite size of 14.5 nm were produced after 24 h of milling. As-synthesized MnFe₂O₄ nanocrystals were found to show soft magnetic behavior at room temperature with saturation magnetization of 53 emu/g. Due to reduced thermal effects, the saturation magnetization increased to 68 emu/g at 5 K. Results show that this method is simple and efficient for the mass production of MnFe₂O₄ nanoparticles.     

Role of (La,Gd) co-doping on the enhanced dielectric and magnetic properties of BiFeO3 ceramics

The effect of the La³⁺ and Gd³⁺ co-doping on the structure, electric and magnetic properties of BiFeO₃ (BFO) ceramics are investigated. For the compositions (x=0 and 0≤y≤0.15) in the perovskite structured La_xGd_yBi_1−(x+y)FeO₃ system, a tiny residual phase of Bi₂Fe₄O₉ is noticed. Such a secondary phase is suppressed with the incorporation of ‘La’ content (x). The magnitude of dielectric constant (ε_r) increases progressively by increasing the ‘La’ content from x=0 to 0.15 with a remarkable decrease of dielectric loss. For x=0.15, the system La_xGd_yBi_1−(x+y)FeO₃ exhibits highest remanent magnetization (M_r) of 0.18 emu/g and coercive magnetic field (H_C) of ~1 T in the presence of external magnetic field of 9 T at 300 K. The origin of enhanced dielectric and magnetic properties of La_xGd_yBi_1−(x+y)FeO₃ and the role of doping elements, La³⁺, Gd³⁺ has been discussed.     

Effect of Bi-substitution on the microstructure and electromagnetic properties of YCaZrVIG with low sintering temperature

Bi substituted YCaZrVIG ferrites, Y_2.3−xBi_xCa_0.7Zr_0.3V_0.2Fe_4.42O₁₂ (x=0.1, 0.25, 0.4, 0.5, 0.75) ferrites were prepared by conventional oxide method. The addition of Bi₂O₃ promoted the sintering performance and lowered the sintering temperature from 1420–1230 °C. However, it also resulted in the formation of minor second phases and the decrease of grain size. With the increase of Bi concentration, the dielectric constant increases linearly and then remains unchanged. The dielectric loss decreased firstly and then increased. The saturation magnetization (4πM_s) almost retained unchanged as the Bi concentration increased except for the sample with 0.75. The coercivity (H_c) decreased firstly and reached the minimum of 1.32 Oe at 0.25, and then rose when x>0.25, which was related to the facility of magnetic domain wall motion and magnetic moment reverse. Moderate addition of Bi also can increase the remanence (B_r) by improving sintering process. Additionally, we got the optimum electromagnetic properties in the samples with x=0.25 at 1230 °C: RD>97%, ε_r=15.7, tan δ_e=2.48×10⁻⁴, H_c=1.32Oe, 4πM_S=1663 Gs, B_r=583.91 Gs.     

Enhanced ferroelectric,magnetic and magnetoelectric properties of multiferroic BiFeO3–BaTiO3–LaFeO3 ceramics

A lead–free multiferroic ceramic 0.7BiFeO₃–0.3BaTiO₃ showed strong ferroelectric and piezoelectric properties, but weak magnetic and magnetoelectric properties. We herein expected that the electrical and magnetic properties of 0.7BiFeO₃–0.3BaTiO₃ ceramics could be enhanced by introducing LaFeO₃. (0.7–x) BiFeO₃–0.3BaTiO₃–xLaFeO₃ (x?=?0–0.2) were synthesized by solid-state reaction. All the ceramics formed a perovskite structure, and a morphotropic phase boundary (MPB) between rhombohedral and orthorhombic phases formed at x?=?0.025. The ceramics with MPB composition had high unipolar strain (S_max = 0.14%), piezoelectricity (d₃₃ = 223 pC/N, d₃₃ * = 350?pm/V), ferroelectricity (P_r = 25.67 mC/cm²) and magnetoelectricity (a_ME = 466.6?mV/cm·Oe), which can be attributed to addition of La ions. The improved phase angle also demonstrated augmentation of ferroelectricity on the microscopic view. The ferromagnetism was evidently improved after LaFeO₃ doping, and the remanent magnetization M_r increased from 0.0207 to 0.0622?emu/g with rising x from 0 to 0.075. In conclusion, with strong magnetoelectric properties, the prepared ceramics may be applicable as promising lead–free multiferroic ceramic materials for novel electronic devices.