BiFeO3 Research Articles

In-situ Profiling of Environmental Hazardous Sulfamethoxazole in Aquatic and Artificial Saliva samples Using Perovskite Structured Bismuth Ferrite Incorporated Halloysite Nanotubes

Sulfamethoxazole (SMX), a widely used antibiotic, poses significant environmental and health risks due to its persistence and mobility in water systems, potentially leading to antibiotic resistance and ecological harm. Herein, we developed an electrochemical sensor based on Bismuth Ferrite (BiFeO3)/Halloysite Nanotube (BFO/HNT) composite for sensitive and selective SMX detection. The BFO/HNT composite was synthesized via a hydrothermal method and comprehensively characterized using EDS mapping, HRTEM, XRD, FT-IR, and XPS analysis. The BFO/HNT composite enhances the sensor’s performance due to its unique properties, such as increased electrochemical surface area (ECSA) and efficient electron transfer capability. The B-cation (Fe) in the BiFeO3 matrix plays a crucial role in boosting the electrochemical response by facilitating redox reactions. In addition, the HNTs provide a high surface area and excellent adsorption capabilities, which improve the sensor’s sensitivity by facilitating better interaction with SMX molecules. As the results, the prepared sensor demonstrates an impressive linear detection range of 0.01 to 2 µM and 22 to 122 µM, with a detection limit as low as 0.017 µM. Practical applications were validated by detecting SMX in tap water and artificial saliva, achieving high recovery rates of 98.87 % and 99.11 %.

Incorporation of specific defects through ion bombardment for better ferroelectrics

AbstractIncorporating specific defects into complex oxides facilitates the exploration of exotic phenomena and novel functionalities based on the intricate coupling between the defects and lattice/charge. However, methods for maximizing the density of specific defects while enhancing the desired properties have been rarely explored. In this study, the effect of N+ ion bombardment‐driven specific defects on the properties of bismuth ferrite (BFO) thin films was investigated. Furthermore, atomic structure characterization and computational processing revealed the displacement and orientation of the Fe atoms, which are linearly related to the degree of polarization. The ion bombardment introduced deep‐level trap states within the lattice, leading to a significant reduction in the leakage current and improved insulation performance of the films. By precisely engineering the defect content through N+ ion bombardment, the pure BFO thin films with remarkable and stable ferroelectric properties (remnant polarization, Pr = ∼116.8 µC·cm−2; leakage current, J = ∼1.5 × 10−8 A·cm−2) were fabricated. This innovative defect engineering‐based approach enables the customization and optimization of local ferroelectric order parameters, thereby establishing a solid foundation for designing functionalities across various functional material systems.

Electrical conduction of ferroelectric domains and domain walls in polycrystalline BiFeO3 and Bi5Ti3FeO15 thin films

The unique properties of domain wall conductivity have garnered significant interest for their potential application in non-volatile ferroelectric domain wall memory. In this study, we investigated the electrical conduction within ferroelectric domains and domain walls of polycrystalline BiFeO3 (BFO) and Bi5Ti3FeO15 (BTFO) thin films, which were deposited on Pt/Ta/glass substrates via pulsed laser deposition. BFO thin film consistently demonstrated a (111) orientation, while BTFO thin film exhibited mixed crystallinity, featuring both c-axis and a-axis orientations. This mixed crystallinity in BTFO thin film contributed to a higher remanent polarization of 38.2 μC/cm2 compared to 20.3 μC/cm2 in BFO thin film, which is attributed to the a-oriented crystallinity within the Bi-layered perovskite structure of BTFO thin film. Additionally, BTFO thin film displayed a greater prevalence of 90° domain walls, which enhanced electrical conduction due to charge accumulation, particularly when compared to 180° domain walls. A significant change in resistance was observed when the domain wall was present versus absent, with a more pronounced effect in the BTFO capacitor compared to the BFO capacitor. This is attributed to the higher domain wall conductivity in BTFO thin film, confirming their superiority for use in ferroelectric capacitor devices that leverage domain wall conductivity.

Superior energy storage properties of BiFeO3 doped NaNbO3 antiferroelectric ceramics

NaNbO3 (NN)-based dielectric ceramics for energy storage have garnered significant interest due to their high saturation polarization, low residual polarization, and superior breakdown strength (Eb). However, the low recoverable energy storage density (Wrec) and efficiency (η) significantly limited their practical application. Herein, BiFeO3 (BF) was incorporated into NN to optimize the energy storage performance. The NN-BF ceramics exhibited pronounced antiferroelectric (AFE) relaxor phase, alongside grain size reduction and Eb enhancement, which contributed to a significant increase of Wrec and η. Specially, the optimum Wrec of 4.43 J/cm³ and η of 71.51 % were achieved at the composition of 0.9NN-0.1BF. Besides, stable energy storage performance was maintained over a wide temperature range (20–120 °C). These results highlight the potential of NN-BF relaxor AFE ceramics as promising candidates for high-performance energy storage applications.

Designed Spin-Texture-Lattice to Control Anisotropic Magnon Transport in Antiferromagnets.

Spin waves in magnetic materials are promising information carriers for future computing technologies due to their ultra-low energy dissipation and long coherence length. Antiferromagnets are strong candidate materials due, in part, to their stability to external fields and larger group velocities. Multiferroic antiferromagnets, such as BiFeO3 (BFO), have an additional degree of freedom stemming from magnetoelectric coupling, allowing for control of the magnetic structure, and thus spin waves, with the electric field. Unfortunately, spin-wave propagation in BFO is not well understood due to the complexity of the magnetic structure. In this work, long-range spin transport is explored within an epitaxially engineered, electrically tunable, 1D magnonic crystal. A striking anisotropy is discovered in the spin transport parallel and perpendicular to the 1D crystal axis. Multiscale theory and simulation suggest that this preferential magnon conduction emerges from a combination of a population imbalance in its dispersion, as well as anisotropic structural scattering. This work provides a pathway to electrically reconfigurable magnonic crystals inantiferromagnets.

Study on curie temperature mechanism and electrical properties of BiFeO3-doped (Ba,Ca) (Ti,Sn)O3 ceramics

In this study, we investigated the phase structure, Curie temperature, dielectric properties, piezoelectricity, and energy-storage properties of BiFeO3 (BFO)-modified (Ba0.95Ca0.05) (Ti0.89Sn0.11)O3 (BCTSO) ceramics using both experimental and theoretical methods. The results indicated that the lattice distortion and chaotic distribution of the local charge increased with the BFO content, resulting in a phase transition and transformation from a ferroelectric to a relaxing ferroelectric. First-principles calculations revealed that the Curie temperature decreased with increasing BFO content, primarily because of an increase in the ground state energy. The variation in the permittivity of the BCTSO-xBFO ceramics with temperature and frequency is affected by the phase structure and Maxwell-Wagner interface polarisation, respectively. The electrical modulus measurements indicated that BCTSO-xBFO exhibited non-Debye-type dielectric relaxation for x = 0.0, 0.1, and 0.5 %, whereas BCTSO-xBFO showed Debye-type dielectric relaxation for x = 0.9%.

Exchange Bias Effects in Bismuth Ferrite Nanostructures Produced by Pulsed Laser Deposition

Exchange Bias Effects in Bismuth Ferrite Nanostructures Produced by Pulsed Laser Deposition

Investigation into the adsorption mechanism of Fe(III) by biomass carbon derived from tea residue and its high-value conversion into bismuth ferrite for enhanced activation of peroxymonosulfate towards antibiotics degradation

Water pollution caused by heavy metals and antibiotics adversely affects human health. However, the harmful solid waste generated via traditional pollution removal processes significantly increases the recovery cost. Herein, we study the adsorption mechanism of hydrothermal activated carbon (AHTC) from tea residue on heavy metals, with AHTC having a good adsorption capacity of 699.0 mg/g for Fe(III). We then use one-step hydrothermal synthesis to produce an AHTC/bismuth ferrite composite (BFOC) material using solid waste to perform activation peroxymonosulfate to degrade antibiotics. The experimental results reveal that the BFOC exhibits good photocatalytic performance, with 94.60 % of the oxytetracycline (20 mg/L) sample degraded within 40 min. BFOC also shows catalytic activity against other antibiotics. The reaction mechanism of the catalyst and intermediate of the OTC reaction are also studied. This study offers a new strategy for the adsorption of heavy metals and the degradation of organic pollutants.

Investigation of magnetic and electric properties of bismuth ferrite nanoparticles at different temperatures

Multiferroic bismuth ferrite shows a massive interest in its potential application in magnetic and electronic devices however maintaining high purity in bismuth ferrite nanoparticles at different temperatures is a difficult task for researchers. Several samples are prepared with different annealing temperatures and investigated in different atmospheres to recognize magnetic and electrical properties. A xerogel powder of bismuth ferrite is synthesized by the sol-gel route. The powder then anneals at 500, 600, 700, and 800 °C to form a nanostructure. X-ray diffraction analysis confirms that the annealed samples are in rhombohedral structure with R3c space symmetry and show a significant increase in crystal size and reduction in lattice strain with increasing annealing temperature. FESEM reveals the microstructural features of annealed nanoparticles which represent the conversion of spherical to cubic morphology with annealing temperature. Vibrating sample magnetometer investigations were conducted as a function of annealing and surface (300, 200, 80 K) temperatures. Insignificant variations of saturation magnetization are detected with surface temperature, but considerable degradation is observed with increasing annealing temperatures. The band-gap energy of bismuth ferrite nanoparticles annealed at 500, 600, 700, and 800 ºC is measured and significant escalation is observed from 1.93 to 2.06 eV. Electrical property analyses have been investigated as a function of frequency at different surface temperatures of 50, 100, 150, 200, 250, 300, and 350 °C. Remarkable variations are established in the electric and magnetic properties. Bismuth ferrite has been widely investigated due to its promising multifunctional device applications such as memory devices, spintronics, sensors, actuators, and photocatalytic and photovoltaic applications.

Investigation into the impact of anionic substitution on modulating the optical and catalytic properties of bismuth ferrite nanoparticles

Bismuth ferrite (BFO) nanoparticles have emerged as a non-toxic catalyst with remarkable potential for the photodegradation of various environmental pollutants. A notable departure from conventional approaches, where cations are added as dopant, this study achieved enhanced catalytic performance through anion substitution. Specifically, replacing oxygen atoms with nitrogen introduces spin-polarized defect states within the BFO’s energy gap, resulting in a notable reduction in the energy band gap. Nitrogen doping of bismuth ferrite yields a novel material with exceptional capabilities for the photodegradation of methylene blue dye and the reduction of 4-nitrophenol. Comprehensive characterization, including X-ray diffraction, Fourier-transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy, has unequivocally confirmed the successful incorporation of nitrogen into the BFO nanoparticle lattice. Interestingly, field emission scanning electron microscopy analysis revealed no significant alteration in nanoparticle size after nitrogen doping. Meanwhile, UV-diffuse reflectance spectroscopy unveiled a distinct decrease in the energy gap upon nitrogen incorporation. The observed improvements in catalytic activities can be attributed to nitrogen ions, introduced as substitutes, effectively occupying the oxygen defects within the sample, thereby diminishing recombination centers for photogenerated charge carriers and decreasing recombination rates. Additionally, adsorption kinetics studies underscore the efficacy of the catalyst surface in adsorbing methylene blue and/or 4-nitrophenol, conforming to the Ho pseudo-second-order model. This study not only highlights the exciting potential of nitrogen-doped bismuth ferrite nanoparticles in environmental remediation but also sheds light on the intricate interplay between anion substitution, band structure modification, and catalytic performance enhancement.Graphical

Theoretical Study of Co-Doping Effects with Different Ions on the Multiferroic Properties of BiFeO3 Nanoparticles.

Using a microscopic model and the Green's function theory, the size and co-doping effects on the multiferroic and optical (band gap) properties of BiFeO3 (BFO) nanoparticles are investigated. The magnetization increases, whereas the band gap energy decreases with decreasing nanoparticle size. The substitution with Co/Mn, Nd/Sm, Ce/Ni, and Cd/Ni is discussed and explained on a microscopic level. By the ion co-doping appear different strains due to the difference between the doping and host ionic radii, which leads to changes in the exchange interaction constants for tuning all properties. It is observed that by co-doping with Nd/Sm at the Bi site or with Co/Mn at the Fe site, the multiferroic properties are larger than those by doping with one ion. Moreover, by doping with Ni, the multiferroic properties are reduced. But by adding another ion (for example Ce or Cd), an increase in these properties is obtained. This shows the advantages of the co-doping, its flexibility, and its greater possibility of tuning the multiferroic properties compared to single ion substitution. The band gap energy decreases for all co-dopants. The polarization increases with increasing magnetic field. This is evidence of magnetoelectric coupling, which is enhanced by co-doping with Co/Mn. The observed theoretical results are in good qualitative agreement with the existing experimental data.

Synthesis and investigation of polyvinylpyrrolidone-polymer content on magnetic and electromagnetic properties of electrospun BiFeO3, SrFe12O19, α-Fe2O3 nanostructures

A one-pot electrospinning technique was employed to synthesize polyvinylpyrrolidone (PVP)-based nanofibers containing bismuth ferrite (BiFeO3), strontium hexaferrite (SrFe12O19), and hematite (α-Fe2O3). The influence of PVP polymer concentration on structural properties revealed the formation of pure phases in all samples, except for BiFeO3 nanofibers, which contained an impurity Bi2Fe4O9 phase. Field-emission scanning electron microscope images showed that higher PVP concentrations resulted in longer, thicker nanofiber chains for all samples. Vibrating sample magnetometer analysis indicated that SrFe12O19 nanofibers exhibited strong ferrimagnetic properties with high saturation magnetization (60 emu g−1) and coercivity (5000 Oe), while the other samples displayed weaker magnetic properties. To address the fragility of nanofibers produced via the one-pot method, the highest PVP concentration nanofibers were incorporated into low and high concentrations of paraffin matrices. Electromagnetic testing showed that paraffin concentration significantly increased the real part of electrical permittivity for BiFeO3 nanofibers (from ∼2 to ∼4.5) compared to other compositions (∼2 to ∼3). Impedance results revealed that BiFeO3 nanofibers had the lowest resistance and likely higher reflectivity. Lastly, the real permittivity of nanofibers decreased with increasing frequency, aligning with Koop’s dielectric relaxation theory.

Effect of Bismuth Ferrite Nanoparticles on Physicochemical Properties of Polyvinylidene Fluoride-Based Nanocomposites

Bismuth ferrite (BiFeO3, BFO) is one of the few single-phase crystalline compounds exhibiting strong multiferroic properties at room temperature, which makes it promising for use in various fields of science and technology. The remarkable characteristics of BFO at the nanoscale position it as a compelling candidate for enhancing the functionalities of polymeric nanocomposite materials. In this study, we explore the fabrication of polyvinylidene fluoride (PVDF) nanocomposites with a variable content of BFO nanopowders (0, 5, 10, 15, 20, and 25 wt%) by solution casting in the form of thin films with the thickness of ~60 µm. Our findings reveal that the presence of BFO nanoparticles slightly facilitates the formation of β- and γ-phases of PVDF, known for their enhanced piezoelectric properties, thereby potentially expanding the utility of PVDF-based materials in sensors, actuators, and energy harvesting devices. On the other hand, the increase in filler concentration leads to enlarged spherulite diameter and porosity of PVDF, as well as an increase in filler content above 20 wt% resulting in a decrease in the degree of crystallinity. The structural changes in the surface were found to increase the hydrophobicity of the nanocomposite surface. Magnetometry indicates that the magnetic properties of nanocomposite are influenced by the BFO nanoparticle content with the saturation magnetization at ~295 K ranging from ~0.08 emu/g to ~0.8 emu/g for samples with the lowest and higher BFO content, respectively.

Optimization of self-rectifying analog memristors by insertion of an interfacial layer

Self-rectifying analog memristors have emerged as promising components for neuromorphic computing systems due to their inherent rectifying behavior and analog resistance states. Among these devices, BiFeO3 (BFO) memristors have shown exceptional performance, attributed to the accumulation and migration of oxygen vacancy (Vo··). However, the movement of Vo·· within the structure of the device presents challenges in optimizing their performance. To address this, the insertion of an interfacial layer has been proposed as a strategy to change the movement of Vo·· and enhance the behavior of memristor. In this study, we investigate the optimization of self-rectifying analog memristors by inserting an interfacial layer in BFO memristors. The more significant nonlinearity in high resistance state branch we observed in the current–voltage relationship leads to better rectifying behavior and a larger on/off ratio at room temperature, which indicates that the interfacial layer improves rectifying behavior. Moreover, we propose a model based on the modulation of the interfacial barrier to elucidate the impact of the interfacial layer on the BFO memristor. These findings provide insight into the design principles for optimizing self-rectifying analog memristors, with potential applications in neuromorphic computing.

Effect of sintering temperature on multiferroic properties of Mg-doped Bismuth Ferrite

The research findings from a thorough examination of the impact of sintering temperature are presented in this publication on structural, ferroelectric, ferromagnetic and dielectric properties of Mg-doped Bismuth Ferrite. Bi0.88Mg0.12FeO3 (BMFO) was synthesized using a solid-state reaction technique and sintered at three different temperatures: 750 °C, 800 °C and 830 °C. Structural analysis was performed using Rietveld refinement of XRD data, which confirms the presence of perovskite phase with rhombohedral structure in all samples and also changes in lattice parameters that result from sintering temperature changes. The average crystalline size as well as the lattice strain are calculated using the Williamson-Hall method. The loss tangent and dielectric constant have been examined as a function of frequency revealing a considerable improvement in dielectric properties. SEM analysis was performed to identify the microstructural property of the samples. Ferroelectric properties were studied using a P-E loop which confirms the enhancement in the ferroelectric property as sintering temperature increases. The improvement in the multiferroic nature will be discussed in light of the sintering temperature effect on Mg-doped Bismuth Ferrite.

Strategically designed multiwalled carbon nanotube/bismuth ferrite/polyaniline nanocomposites and unlocking their potential for advanced supercapacitors

Bismuth ferrite (BF) serves a potential electrode-active material due to its peculiar characteristics such as wide voltage window and high specific capacitance, excellent stability, facile synthesis routes, etc. to name a few. Herein we report the strategic design and facile synthesis of multiwalled carbon nanotubes (MWCNT)/BF/polyaniline (PANI) nanocomposites, particularly for application in advanced supercapacitors. The MWCNT/BF/PANI nanocomposite architecture is a strategic design in which the maximum available surface area is utilized for the electrode nanostructure with increased porosity that allows easy movement of electrolyte-ions through it. The uniform arrangement of BF on MWCNTs helps in mitigating the possible agglomeration, further augmenting the surface area for an enhanced charge storage. The strategic layout of PANI on BF-decorated MWCNTs has given a coral-like structure for the nanocomposite electrode which significantly increased the surface area, reduced ion pathways and facilitating better access to electrolytic K+ ions. The MWCNT/BF/PANI nanocomposite electrode exhibits a specific capacitance of 3640 F g−1 at a current density of 5 A g−1. The innovative design as well as the synergy between the individual components of the nanocomposite electrode play a pivotal role in attaining the enhanced electrochemical performance.

Photocatalytic properties of BiFeO3 (BFO) synthesized by microwave-assisted hydrothermal method

Photocatalytic properties of BiFeO3 (BFO) synthesized by microwave-assisted hydrothermal method

Effects of Non-Stoichiometry and Strain on Ferroelectric Properties of CVD-Grown Bismuth Ferrite Films

Effects of Non-Stoichiometry and Strain on Ferroelectric Properties of CVD-Grown Bismuth Ferrite Films

Investigation of the effect of strontium substitution in bismuth ferrites for enhanced structural and optical properties using experimental and DFT approaches

BiFeO3 doped with Sr, having the composition Bi1-xSrxFeO3 (0.00 ≤ x ≤ 0.20), was synthesized using the auto-combustion method. Various characterization techniques were employed to investigate the structural, morphological, and optical properties. X-ray diffraction (XRD) patterns confirmed that the materials exhibit a distorted rhombohedral structure with the space group R3c. The average crystallite size was determined to be in the range of 18–28 nm. A decrease in the lattice parameters was observed due to the contraction of the unit cell volume (373.83–371.49 Å) caused by Sr doping. Scanning electron microscopy (SEM) images revealed a reduction in grain size, suggesting the suppression of grain growth with Sr doping. Fourier-transform infrared (FTIR) studies identified two strong peaks at 552 cm−1 and 449 cm−1, confirming the perovskite structure of the materials. The optical band gap was found to decrease from 2.14 eV to 2.05 eV with increasing Sr concentration. Theoretical calculations of electronic and optical properties using density functional theory (DFT) were conducted. The calculated direct optical band gaps (2.0 eV, 2.22 eV, 2.1 eV, and 2.09 eV) for Bi1-xSrxFeO3 samples at doping levels x = 0.0, 0.10, 0.15, and 0.20, respectively, were in good agreement with the experimental results. These findings provide valuable insights into the tunability of electronic and optical properties in Sr-doped BiFeO3, making them promising candidates for various technological applications.

Finite Size Effects in Antiferromagnetic Highly Strained BiFeO3 Multiferroic Films

AbstractEpitaxially strain‐engineered tetragonal (T)‐like BiFeO3 (BFO) is a multiferroic material with unique crystallographic and physical properties compared to its bulk rhombohedral parent. While the effect of this structural change on ferroelectric properties is understood, the influence on correlated antiferromagnetic (AFM) properties, especially with reduced film thickness, is less clear. Here, the AFM behavior of T‐like BFO films 9–58 nm thick on LaAlO3 (001) substrates fabricated by pulsed laser deposition was studied using conversion electron Mössbauer spectroscopy and X‐ray diffraction. The key findings include: i) Ultrathin T‐like BFO films (<10 nm) show a decoupling of magnetic and structural transitions, with the polar vector tilted 32 degrees from [001] in 9–13 nm films. ii) Films thinner than 13 nm exhibit no structural transition down to 150 K, with a Néel (TN) transition at ≈290 K, ≈35 K lower than thicker films. Interestingly, the TN scaling with thickness suggests realistic scaling exponents considering a critical correlation length for C‐type AFM order, rather than G‐type. The results show that finite size effects can tailor transition temperatures and modulate AFM wave modes in antiferromagnetic oxides, with implications for AFM spintronics for future information technologies.