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This study investigates the photovoltaic performance of bismuth vanadate (BiVO₄)/bismuth ferrite (BiFeO₃) heterostructures. By varying the pre-annealing temperature of the BiVO₄ layer, we have achieved the significant enhancement in the open-circuit voltage (V oc) with the spontaneous formation of the polarized Bi 4 V 2 O 11 interfacial layer. X-ray diffraction analysis confirms a pure rhombohedral distorted perovskite structure for BiFeO₃ and a monoclinic crystallographic nature for BiVO₄. SEM analysis exhibits a porous structure with small spherical grains in the BiVO₄ layer, with the dense and smooth surface of the BiFeO₃ layer. The heterostructures observed in a red-shifted absorption edge are compared with the individual materials, which indicates an improved light absorption. Tauc plot analysis has yielded the direct bandgap values of 1.88 eV and 1.83 eV for the BiVO 4 annealing temperatures at 150 and 500 °C, respectively. The overall power conversion efficiency (η) has remained low at 0.003 % and 0.005 %, demonstrating the potential of interfacial engineering to optimize the photovoltaic properties of BiVO₄/BiFeO₃ heterostructures. [ABSTRACT FROM AUTHOR]

Incorporating 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. [ABSTRACT FROM AUTHOR]

Photocatalytic degradation is vital to combat water pollution, utilizing sunlight to degrade organic contaminants. Bismuth ferrite (BFO), a multiferroic, is particularly effective as a photocatalyst as it can be magnetically recovered and reused. This study presents a comprehensive investigation into the photocatalytic degradation of organic dyes using BFO nanoparticles (NPs) synthesized through a sol–gel method. Degradation studies are conducted under different pH conditions (neutral, acidic, or basic) and using both cationic (methylene blue and malachite green) and anionic (methyl orange and Congo red) dyes under controlled photocatalytic conditions. Our findings reveal that cationic dyes show enhanced degradation in basic conditions, whereas anionic dyes are more effectively degraded in acidic conditions. The BFO NPs are magnetically recovered from the solution with approximately 98% efficiency and subsequently reused for dye degradation. This study demonstrates the potential of BFO NPs in photocatalytic applications paving the way for future research towards environmental clean-up. [ABSTRACT FROM AUTHOR]

BiFeO 3 (BF) based ceramics are inspiring great interest in advanced pulsed power applications owing to their giant spontaneous polarization, meanwhile limited by the significant leakage current. In this work, Sr 0.7 Bi 0.2 TiO 3 (SBT) modified 0.7BiFeO 3 -0.3BaTiO 3 (BF-BT) ternary lead-free relaxor ferroelectric ceramics are investigated to elaborate the dielectric performances, including the impedance, relaxor behavior, ferroelectric and energy storage, and strain properties. The substitution of SBT induces a phase transition from an R 3 c to an average pseudo-cubic structure and forms a secondary phase at high dopants. Simultaneously, the resistivity, electrically homogeneous, and band gaps are increased significantly, related to the inhibition of oxygen vacancy formation. Besides, the ferroelectric long-range order is disrupted, which promotes the formation of local defect fields and polar nanoregions. The structural heterogeneity for the higher doped components leads to an increased relaxation behavior with an almost hysteresis-free polarization response to external electric fields. Excellent temperature-insensitive dielectric response and promising dielectric energy storage properties in low electric fields are achieved, respectively. These results indicate that the SBT modification is an effective route in regulating the dielectric performance of bismuth ferrite based relaxors. [ABSTRACT FROM AUTHOR]

Yttrium (Y) and cobalt (Co) co-doped bismuth ferrite (BFO) nanopowders were synthesized by the sol–gel method. The purity of the phase of the samples was confirmed by the X-ray diffraction technique. Both grains and grain boundaries contribute to the electrical response of the samples. The modulus studies show that the charge carriers can perform both long- and short-range mobility. Meanwhile, the Nyquist plot analysis confirms the samples' non-Debye-type relaxation behaviour and negative temperature coefficient resistance nature. The frequency-dependent AC conductivity obeys the power law A ω s at a higher frequency. AC conductivity increases from 1.300 × 10–5 to 8.463 × 10–4 S m–1, increasing Y and Co contents in the BFO sample. The temperature dependence of the AC conductivity suggests the presence of different conduction processes for all the samples. [ABSTRACT FROM AUTHOR]

Bismuth ferrite (BiFeO3)‐based high‐temperature piezoelectric ceramics have high Curie temperatures and excellent thermal stability; however, their applications are limited by inadequate piezoelectric performance due to large coercive fields and high leakage conduction. This study investigates the impact of MnO2 doping on the phase transition, defect structure, domain morphology, as well as the dielectric, ferroelectric, and electrical conduction behaviors of 75BiFeO3–25BaTiO3 ceramics sintered under an oxygen atmosphere. A structural transformation from distorted rhombohedral to pseudo‐cubic symmetry was observed with increasing MnO2 content, accompanied by domain fragmentation. MnO2 doping at an appropriate level inhibited defects such as Fe′Fe$\ {\mathrm{F}}{{{\mathrm{e^{\prime}}}}_{{\mathrm{Fe}}}}$ and VO2−⋅⋅$V_{{{{\mathrm{O}}}^{{\mathrm{2}} - }}}^{\centerdot \centerdot }$. Regarding electrical properties, the reduction in rhombohedral distortion and enhancement in the pseudo‐cubic phase after MnO2 doping resulted in decreased remanent polarization and electrostrain, which could potentially hinder piezoelectric response. However, appropriate MnO2 doping effectively reduced leakage conduction, significantly enhancing the poling efficiency of the ceramics. The maximum d33 value of 107 pC/N and kp of 0.36 were achieved at an MnO2 doping content of 0.1 wt.%. Excessive MnO2 addition may generate 2Mn′Ti−VO2−⋅⋅${\mathrm{2M}}{{{\mathrm{n^{\prime}}}}_{{\mathrm{Ti}}}}-V_{{{{\mathrm{O}}}^{{\mathrm{2}} - }}}^{\centerdot \centerdot }$ defect dipoles, as indicated by increased coercive field (Ec) and dielectric loss. The observed increase in high‐temperature resistivity with MnO2 content is primarily attributed to reduced grain size and increased concentration of mobile defects. This study provides valuable insights for further research on the application of 75BiFeO3–25BaTiO3 systems in high‐temperature piezoelectric devices. [ABSTRACT FROM AUTHOR]

The paper presents the results of a study of the microwave absorption properties of ceramic materials based on bismuth ferrite containing rare earth elements, as well as systems of solid solutions (1 − x)BiFeO3–xPbFe 1 / 2 Nb 1 / 2 O3 in a wide range of component concentrations. The methodology for measuring and calculating the parameters of samples of the materials under study is described. The influence of structural and microstructural factors on the average and maximum level of microwave absorption of the materials under study in a wide frequency range is analyzed. A comparison of the microwave absorbing properties of these materials with industrial absorbers has been carried out, and prospects for application in microwave technology have been shown. [ABSTRACT FROM AUTHOR]

Water contamination has become a global concern, and the prevalence of complex substances known as emerging contaminants constitute a risk to human health and the environment. This work focused on an innovative approach of integrating sonolysis and photocatalysis to remove a standard textile dye efficiently. A highly photo-active, bismuth ferrite (BiFeO3) nanocatalyst with single particle sizes between 86 and 265 nm was obtained by a novel one-pot combustion method using a deep eutectic solvent as a precursor. The said catalyst was thoroughly characterized and evaluated for photocatalytic and sono-photocatalytic degradation of rhodamine B (RhB). Photocatalytic experiments were conducted under visible light irradiation (450–600 nm). Sono-photocatalytic (SPC) experiments were conducted, focusing on the influence of operational parameters (frequency, power, and pH) on the degradation performance. High-frequency values of 578, 866, and 1138 kHz were explored to promote cavitation dynamics and reactive species generation, improving removal efficiency. Results demonstrated that when sonolysis and photocatalysis were performed separately, the degradation efficiency ranged between 85 and 87%. Remarkably, when the combined SPC degradation was carried out, the RhB removal reached about 99.9% after 70 min. It is discussed that this behavior is due to the increased generation of OH• radicals as a product of the cavitation phenomena related to the ultrasound-assisted process. Moreover, it is argued that SPC significantly improves reaction kinetics and mass transfer rates, facilitating catalyst dispersion and contact with the RhB molecules. Finally, the stability of the catalyst was evaluated in five repeated RhB removal cycles, where the activity remained consistently strong. [ABSTRACT FROM AUTHOR]

Chromium doped bismuth ferrite (BFCO) based thin films with controllable chemical composition and structural properties were grown by bipolar HiPIMS in Ar:O 2 mixt gas environment. The energy, amount and type of the accelerated ions were adjusted by varying the positive discharge pulse amplitude, duration and delay from the initial negative pulse. Bi/(Fe + Cr) compositional ratio obtained from EDX decreased as the positive pulse amplitude and duration were augmented and the delay between negative and positive pulses was diminished. XRD measurements revealed the presence of bismuth oxide secondary phases for the films exhibiting Bi overstoichiometry. The diffraction pattern of the sample with Bi/(Fe + Cr) of 1 showed peaks corresponding only to the BiFeO 3 hexagonal structure. This film presented a lower piezoresponse (d 33 = 40 p.m./V) than the BFCO sample obtained by monopolar HiPIMS where no positive discharge pulse was used and for which the EDX results revealed a Bi/(Fe + Cr) of 2.1 (d 33 = 60 p.m./V). The photo-piezocatalytic properties of both these BFCO coatings for MB dye degradation were studied. The results revealed that BFCO layer deposited on FTO substrate by monopolar HiPIMS (Bi/(Fe + Cr) = 2.1) under ultrasonic vibrations exhibited a remarkable piezocatalytic performance, with 75 % degradation of MB dye within 120 min (reaction rate constant k value 0.0124 min−1). Additionally, when both visible light and mechanical oscillations were used simultaneously, the degradation efficiency was further increased up to 80 %, with k value seven-fold higher than that of photocatalysis. The proposed approach provides an environmentally friendly and innovative way to synthesize high efficiency piezo-photocatalyst for wastewater treatment and energy applications. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting is a promising approach towards a sustainable and renewable energy source. However, the demand for high anodic potential and sluggish kinetics of oxygen evolution reaction (OER) restrict the efficiency and feasibility of the water-splitting process. In this quest, transition metal oxides and alloys are considered potential candidates owing to their natural occurrence and high redox potential for OER. However, many associated challenges in their use are still there to be addressed. Here, we designed a new class of bismuth-doped iron oxide on exfoliated graphene oxide by optimizing the metal loading on the conductive support to facilitate the flow of charge during catalysis. The catalytic ability of the synthesized Bi-doped nanocomposites was evaluated in activating the OER under extreme alkaline conditions (1 MKOH). On screening different combinations, 20Bi–Fe2O3@GO was identified as the most efficient and sustainable electrocatalyst even under harsh operating conditions, with an onset potential of 1.48 V and a Tafel slope of 65 mV/dec. The current study offers a new class of Bi-doped electrocatalysts, where the precise doping of Bi and the optimized loading of metal was found the key to achieving low onset potential and high current density to initiate OER. [ABSTRACT FROM AUTHOR]

Epitaxial strain is known to significantly influence the structural and functional properties of oxide thin films. However, its impact on point defect concentration has been less explored. Due to the challenges in experimentally measuring thin-film stoichiometry, computational studies become crucial. In this work, we use first-principles calculations based on density functional theory to investigate the formation and stability of Bi vacancies and Bi-O vacancy pairs in BiFeO3 (BFO) under (111) epitaxial strain. Our results demonstrate that compressive strain (−4%) decreases the formation enthalpy of Bi vacancies by 0.88 eV, whereas tensile strain (4%) increases it by 0.39 eV. Out-of-plane (OP) Bi-O vacancy pairs exhibit enhanced stability under both compressive and tensile strain, with formation enthalpy reductions of 1.49 eV and 1.05 eV, respectively. In contrast, in-plane (IP) vacancy pairs are stabilized under compressive strain but are insensitive to tensile strain. Finally, we discuss how these findings influence Bi stoichiometry during thin-film growth and the role of local strain fields in the formation of conducting domain walls. [ABSTRACT FROM AUTHOR]

New xYFeO 3 – (1-x) BiFeO 3 (0.0 ≤ x ≤ 1.0) multiferroic composites were prepared successfully via the chemical co-precipitation followed by high energy mechanical blending. For the structural analysis, assessment of phase purity, and characterization of oxidation states, XRD, FTIR and XPS methods were utilized, respectively. Furthermore, morphological investigations and elemental distribution within the composite samples were elucidated through FESEM and TEM imaging techniques. The VSM results indicated that the values of M s and M r increase alternately from 0.553emu/g and 0.049emu/g to 1.210emu/g and 0.166emu/g, respectively, with an increase in the YFO content from 20 % to 80 %. These values of M s do not follow a linear combination of the base phases, and the magnetization of each composite sample is accompanied by an additional value. This additional value may arise from the residual strain and interfacial magnetic and electrical interactions between the parent phases. The measurements of dielectric properties disclosed that the behavior of the samples follows the Maxwell-Wagner polarization. Moreover, the values of ε′ at the frequency of 200 Hz increased from 149 to 303 as the BFO content rose from 20 % to 80 %. In addition, the lowest recorded tanδ value was 0.56 for the 6Y4B sample at 200 Hz. Furthermore, the conductivity measurements showed that the behavior of all samples follows Johnscher's power law. • The phase-pure YFeO 3 /BiFeO 3 nanocomposites with well-dispersed particles were synthesized using the reverse co-precipitation. • The magnetostriction effect in BFO and the ferroelectric properties of YFO altered the overall magnetization in the system. • The significant enhancement of the coercive field relative to the original phases was emphasized in all composite samples. • The rise in the YFO content in the composite specimens led to a drop in the dielectric constant. [ABSTRACT FROM AUTHOR]

In this study, we synthesized and characterized Nd and Co modified bismuth ferrite nanoparticles (BNFCO) using mechanical milling. X-ray diffraction (XRD) analysis has provided confirmation of the distorted rhombohedral, mixed rhombohedral-tetragonal and tetragonal perovskite structure with space group R 3 c and P2mm. Notably, these nanoparticles exhibited a high dielectric constant and low loss values at low frequencies and high temperatures, remaining around 103 up to 373 K before increasing to approximately 104, which opens new avenues for exploring temperature-sensitive dielectric properties. The AC conductivity adhered to Jonscher's power law, with dc conductivity values ranging from 10−5 to 10−3 s/cm, representing a significant advance in understanding electrical conduction in nanomaterials. Furthermore, we assessed the electrochemical behavior of the fabricated samples at varying concentrations using cyclic voltammetry, Galvanostatic charge and discharging (GCD), and electrochemical impedance spectroscopy (EIS) on a modified electrode. BNFCO (0.20) displayed exceptional properties with a capacitance of 510 F g−1 and a capacitance retention of 93.9 % after 5k cycles, making BNFCO nanomaterials potential candidates for supercapacitor applications. The multifunctional properties of Nd and Co modified bismuth ferrite nanoparticles presented in this study offer unparalleled opportunities for transformative applications in supercapacitors and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Bismuth ferrite, whose formula is BiFeO3 (BFO), is widely studied for its photovoltaic and photocatalytic properties. In this study, samples of this material were synthesized using the microwave-assisted hydrothermal method with the aim of measuring its ability to discolor contaminants present in water in previously formulated concentrations through photocatalysis. Photocatalysis is a process with great potential for applicability in the decontamination of effluents. The analysis process used a 1:1 molar ratio of bismuth nitrate to iron nitrate, with the addition of potassium hydroxide to the aqueous solution. Two samples were synthesized at different temperatures, specifically 140 °C and 160 °C. An X-ray diffraction analysis revealed that the synthesized samples were in an amorphous state. Photocatalytic tests were carried out to evaluate the ability of these materials to decolorize rhodamine B present in water in a previously known proportion. A sample synthesized at 140 °C successfully decolorized the solution within 60 min, providing its potential application in photocatalytic processes for decolorization of organic substances from wastewater. In turn, a sample synthesized at 160 °C discolored or contaminated in a slightly longer time. The samples were also subjected to a temperature of 750 ºC until crystallinity was reached. However, photocatalytic tests with crystalline samples performed less well than amorphous samples. [ABSTRACT FROM AUTHOR]

Recent advances in photocatalysis include the development of floating catalysts since they assure efficient and rapid recollection of the catalysts from the purified liquid, besides enhancing the availability of photons at the catalytic surface. Bismuth ferrite (BiFeO3 and BFO) is a multifunctional perovskite material renowned for its excellent photocatalytic properties. Since bandgap of BFO falls in the visible spectrum, BFO nanoparticles could be combined with a suitable floating substrate to develop efficient visible light photocatalysts. Here, we report the synthesis of BFO–polydimethylsiloxane (PDMS) hybrids for photocatalytic applications, where sol-gel–synthesized BFO nanoparticles are immobilized on a floating porous PDMS sponge. The successful incorporation of the nanoparticles on PDMS is confirmed using Raman spectroscopy, scanning electron microscopy, and energy dispersive x-ray spectroscopy. The photocatalytic activity of the floating catalysts was studied by monitoring the degradation of malachite green dye under visible light irradiation. The effect of the amount of BFO immobilized, and the area and thickness of the PDMS sponge on the photocatalytic activity of the floating catalysts were investigated. An efficiency of 80.5% was obtained when the weight of BFO immobilized on the PDMS sponge was 5 mg. The method yields degradation efficiencies comparable with or higher than that of conventional BFO powder catalysts, even with 6–18 times less catalyst loading. The method introduces the fabrication of recyclable floating photocatalysts of notable efficiency using significantly less amount of BFO nanoparticles, which could be further modified by approaches such as doping, functionalization, or composite formation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Construction of a ferroelectric Bi 12 (Bi 0.5 Fe 0.5)O 19.5. • The activation of H 2 O 2 was significantly increased. • Degradation PET-MPs via piezocatalysis/Fenton-like mechanism. • With mild reaction conditions and high performance. Pollution of microplastics (MPs) has been drastically threating human health, however, whose elimination from the environment by current approaches is inefficient due to their high molecular weight, strong hydrophobicity and stable covalent bonds. Herein, we report a novel and highly-efficient route to degrade MPs contaminants through synergistically piezocatalytic and Fenton-like activation of H 2 O 2 by a ferroelectric Bi 12 (Bi 0.5 Fe 0.5)O 19.5 catalyst under ultrasound treatment. For 10 g/L polyethylene terephthalate microplastics (PET-MPs), the synergistic strategy reached a 28.9 % removal rate in 72 h, which is greatly enhanced in comparison to the individual piezocatalysis and Fenton (Fenton-like) activation. By optimizing the types of oxidants (H 2 O 2 , peroxymonosulfate and peroxydisulfate) and bismuth ferrite catalysts (non-piezoelectric Bi 2 Fe 4 O 9 and piezoelectric BiFeO 3 /Bi 12 (Bi 0.5 Fe 0.5)O 19.5), it was revealed that H 2 O 2 is the best oxidant, and the piezoelectric Bi 12 (Bi 0.5 Fe 0.5)O 19.5 with a high aspect-ratio morphology showed higher activity than the Bi 2 Fe 4 O 9 and BiFeO 3. The catalyst dosage and H 2 O 2 concentration were further optimized, and the good durability of the catalyst was also demonstrated through multiple uses. Different characterization technologies demonstrated the occurrence of PET-MPs oxidation and fragmentation during the treatment process. The plausible mechanism of synergistically piezocatalytic and Fenton-like H 2 O 2 activation was proposed based on measurements of band structure, piezoelectric property and reactive oxygen species generation. Finally, we detected the intermediates and determined a possible degradation route of PET-MPs. The toxicity assessment indicated that the produced intermediates have low toxicity and potential risks to the environment. [ABSTRACT FROM AUTHOR]

In this study, the field‐effect generated by illuminated p‐type ferroelectric bismuth ferrite (BiFeO3 or BFO) semiconductor film is utilized to modulate the water‐splitting performance of a system with a macroscopic spatial separation between the anode and cathode. When the BFO film in contact with an electrolyte is illuminated with a light of sufficiently high frequency, an electrolytic conducting channel is formed due to the field effect induced by photoexcited charge carriers in the BFO film, which in turn alters the water‐splitting pathway and the reaction mechanism. The field effect can be modulated by changing the orientation of the ferroelectric polarization in the BFO film. With a BFO film of 4.5 mm channel length and an overall upward ferroelectric polarization direction, a ∼30% increase in water‐splitting performance in a neutral‐pH electrolyte is achieved in the presence of field‐effect induced by a 20 mW 405 nm light source. The mechanism behind the field‐effect modulation is also further verified by monitoring the pH of the electrolyte during the water‐splitting process and conducting thresholding analysis on the recorded data. The field‐effect modulation described in this study can potentially be used to enhance the performance of a photoelectrochemical water‐splitting system by taking advantage of the presence of light illumination in the system or be utilized in electrochemical sensing applications. [ABSTRACT FROM AUTHOR]

Room‐temperature (RT) multiferroic materials have received significant research attention for various potential applications; however, their properties are not suitable for real‐world implementation. In this study, a nano‐scale localized flexoelectric effect is introduced to enhance the RT multiferroic performance of epitaxial bismuth iron oxide (BiFeO3; BFO) thin films by embedding 10 mol% Ba(Cu1/3Nb2/3)O3 (BCN) nano‐clusters into the host BFO film, which originally has a rhombohedral crystal structure. By utilizing nano‐clustering, a large out‐of‐plane coherent strain is localized around the nano‐clusters, resulting in a highly strained tetragonality of the BFO structure; subsequently, the films exhibit peculiar types of domains and domain walls, such as nano‐scale rotational vortices and antiparallel dipole configurations. These peculiar domain structures, which originate from the localized flexoelectric effect at the nano‐scale, enable excellent ferroelectric, ferromagnetic, and RT multiferroic magnetoelectric coupling. This study reveals that the local variation in the localized flexoelectric field around nano‐clusters considerably impacts the formation of unusual domain‐wall structures. This suggests that the controlled introduction of nano‐clusters with different crystal structures is promising for achieving the desired multiferroic properties. [ABSTRACT FROM AUTHOR]

Humidity sensors using triboelectric nanogenerators (TENGs) technology can provide continuous operation without the need for additional batteries. These sensors provide sustainable and self-powered humidity monitoring solutions, that can be utilized in various agriculture platforms and food processing industries. In this work, a sol-gel method is utilized to process the bismuth ferrite (abbreviated as BFO) materials and a simple mould pressing method to obtain freestanding Ethylene-vinyl acetate (abbreviated EVA)-BFO composites. These composites were characterized to shed light upon structural and microstructural properties. The single electrode mode operating TENG was fabricated having 2 cm × 2 cm active area at various wt.% of BFO onto EVA-based composites to compare the electrical response. The 5 wt.% BFO-EVA-based composites/FEP-based TENG generates a voltage and current of 45 V and 800 nA. Further, the TENG device was tested for long-term stability for 400 s, and charging of various capacitors having capacitance values such as 0.1 μF, 1 μF, 4.7 μF, and 10 μF along with 3 times charging/discharging cycles of 0.1 μF capacitor have been demonstrated. The humidity sensing mechanism elucidated which follows the conduction process based on the Grotthuss proton hopping mechanism. The TENG demonstrates a sensitivity of 0.53 V/RH% over the relative humidity range from 25 % to 85 %. The powering of the wristwatch confirms that fabricated TENG can be a reliable power source for future low-power electronics. [ABSTRACT FROM AUTHOR]

The study examined the structural, optical, dielectric, and magnetic characteristics of Bismuth Ferrite nanoparticles modified by rGO prepared by using the solgel via auto-combustion process. Each sample has a non-uniform surface morphology and a rhombohedral structure with space group R 3 c. With increasing rGO doping concentrations, the bandgap energy drops, and visible area PL emissions were detected. A frequency dependent dielectric experiment conducted at room temperature (0–1 MHz) reveals that as applied frequencies increase, the dielectric constant and loss factor both drop. The presence of grain and grain boundaries within the particles crystalline structure is shown via impedance analysis. It was discovered that magnetization rise as rGO concentration rise. The BFO and rGO-doped BFO nanoparticles demonstrated strong magnetoelectric coupling. [ABSTRACT FROM AUTHOR]

Nanocatalytic immunotherapy holds excellent potential for future cancer therapy due to its rapid activation of the immune system to attack tumor cells. However, a high level of N-glycosylation can protect tumor cells, compromising the anticancer immunity of nanocatalytic immunotherapy. Here, we show a 2-deoxyglucose (2-DG) and bismuth ferrite co-loaded gel (DBG) scaffold for enhanced cancer piezocatalytic immunotherapy. After the implantation in the tumor, DBG generates both reactive oxygen species (ROS) and piezoelectric signals when excited with ultrasound irradiation, significantly promoting the activation of anticancer immunity. Meanwhile, 2-DG released from ROS-sensitive DBG disrupts the N-glycans synthesis, further overcoming the immunosuppressive microenvironment of tumors. The synergy effects of ultrasound-triggered and glycosylation inhibition enhanced tumor piezocatalytic immunotherapy are demonstrated on four mouse cancer models. A "hot" tumor-immunity niche is produced to inhibit tumor progress and lung metastasis and elicit strong immune memory effects. This work provides a promising piezocatalytic immunotherapy for malignant solid tumors featuring both low immunogenicity and high levels of N-glycosylation. N-glycosylation has a significant role in immunosuppressive tumor microenvironment (TME). Here, the authors design an injectable ROS-sensitive hydrogel scaffold co-delivering piezocatalyst BiFeO3 and glucose/mannose analog 2-deoxy-d-glucose alleviating N-glycosylation inhibition and thereby effectively stimulating immune responses within TME. [ABSTRACT FROM AUTHOR]

In recent years, multiferroic compounds have earned the interest of the scientific community due to their potential applications. Bismuth Ferrite possesses ferroelectricity and antiferromagnetism in the same phase. Being the multiferroic in the same phase, it is an ideal candidate for potential applications in devices. Regardless of this, the application of this material is limited due to factors like high leakage current and larger dielectric loss. Multiferroic properties can be improved by adding elements to maximize its applications. Researchers have examined the structural, electrical, magnetic, and optical properties of the parent and doped BFO. Here, some general information on the preparation techniques of bismuth ferrite and its properties are discussed. [ABSTRACT FROM AUTHOR]

The severe acute respiratory syndrome caused by coronavirus-2 (SARS-CoV-2) is recognized as a worldwide health issue in the coronavirus disease (COVID-19) pandemic. The development of highly selective and sensitive biosensor probes for the detection of coronavirus is one of the essential requirements to prevent the disease. DNA-based surface plasmon resonance (SPR) biosensor plays a vital role in the highly selective and sensitive detection of SARS-CoV-2. In this work, we design a multilayer structure of SPR biosensor for rapid detection of the SARS-CoV-2 by using black phosphorous (BP), bismuth ferrite (BiFeO3), and thiol-tethered ssDNA. Herein, three distinct SPR biosensor structures i.e. BK-7 Prism-Ag-BiFeO3-ssDNA (ST-I), BK-7 Prism-Ag-BP-ssDNA (ST-II), and BK-7 Prism-Ag-BiFeO3-BP-ssDNA (ST-III) are used to identify SARS-CoV-2. Thiol-tethered ssDNA works as a ligand for selective detection of coronavirus. The multilayer structure of SPR biosensors is analyzed using the transfer matrix method (TMM). It is found that ST-III shows maximum sensitivity (356.19°/RIU), detection accuracy (2.57), quality factor (122.40 RIU− 1), and limit of detection (1.40 × 10–5). This work may lead to the development of highly sensitive SPR biosensors for the rapid and label-free detection of SARS-CoV-2. [ABSTRACT FROM AUTHOR]

The study utilized the theory of interionic potentials and included analytical functions to account for the volume-dependent short-range force constant. Specifically, a modified version of the Shanker equation of state was used, and expressions were established for isothermal bulk modulus and its pressure derivatives. The researcher extensively analyzed the bismuth ferrite (BiFeO3) material at pressures up to 10 GPa. The result obtained by the newly derived equation of state is compared against previously obtained equations of state, including the Shanker and Vinet equation of state and experimental data. Graphical representations demonstrate the changes in pressure, bulk modulus, and pressure derivative of bulk modulus with compression. The result shows that the newly developed equation of state provides superior outcomes compared to the Shanker and Vinet equations, particularly at high compression levels, due to the inclusion of higher-order compression terms. [ABSTRACT FROM AUTHOR]

In ferroic materials, giant susceptibilities can be realized at artificially constructed phase boundaries through deterministic manipulation of the order parameter. Here, emergent ferroelectric structural phase evolution behavior is demonstrated through a synergistic combination of A‐site doping and strain engineering. Using chemical solution deposition derived (001)‐oriented Sm‐substituted bismuth ferrite (Bi1‐xSmxFeO3) films as a prototypical system, a morphotropic phase boundary comprising a coexistence of four distinct crystallographic phases is uncovered. These ferroelectric, polar, and nonpolar phases form a nanoscale mixture without the presence of crystallographically hard boundaries. The system thus possesses the ability to show both polarization rotation and extension, effectively releasing the polarization from its crystallographic constraint. Consequently, both robust ferroelectric properties and giant electromechanical responses are obtained. For instance, the optimized composition with x = 0.14 has a remnant polarization of 2Pr = 103 µC cm−2 and electromechanical response 175% that of undoped BFO. These findings showcase the tremendous potential of synthetic phase boundaries, particularly in the context of lead‐free functional multiferroics. [ABSTRACT FROM AUTHOR]

Encapsulating antiepileptic drugs (AEDs), including ethosuximide (Etho), into nanoparticles shows promise in treating epilepsy. Nanomedicine may be the most significant contributor to addressing this issue. It presents several advantages compared to traditional drug delivery methods and is currently a prominent area of focus in cancer research. Incorporating Etho into bismuth ferrite (BFO) nanoparticles within diverse controlled drug delivery systems is explored to enhance drug efficacy. This approach is primarily desired to aid in targeted drug delivery to the brain's deepest regions while limiting transplacental permeability, reducing fetal exposure, and mitigating associated adverse effects. In this investigation, we explored Etho, an antiepileptic drug commonly employed for treating absence seizures, as the active ingredient in BFO nanoparticles at varying concentrations (10 and 15 mg). Characterization of the drug-containing BFO nanoparticles involved scanning electron microscopy (SEM) and elemental analysis. The thermal properties of the drug-containing BFO nanoparticles were evaluated via differential scanning calorimetry (DSC) analysis. Cytotoxicity evaluations using the MTT assay were conducted on all nanoparticles, and human neuroblastoma cell line cultures (SH-SY5Y) were treated with each particle over multiple time intervals. Cell viability remained at 135% after 7 days when exposed to 15 mg of Etho in BFO nanoparticles. Additionally, in vitro drug release kinetics for Etho revealed sustained release lasting up to 5 hours with a drug concentration of 15 mg. [ABSTRACT FROM AUTHOR]

We perform dielectric and impedance spectrums on the compressively-strained ceramics of multiferroic bismuth ferrite. The subsurface-nanolayer quasipolarons manifest the step-like characteristic of pressure-dependent transient frequency and, furthermore, pressure-dependency fails in the transformation between complex permittivity and electrical impedance, which is well-known in classic dielectric physics, as well as the bulk dipole chain at the end of the dissipation peak. [ABSTRACT FROM AUTHOR]

Bi 0. 90 Sm 0.1 Fe 0.97 Cr 0.03 O 3 @PANI core-shell structures were made by a two-step method, first, bismuth ferrite nanoparticles by hydrothermal method and then, aniline core-shell by co-precipitation method. The bismuth ferrite (BFO) XRD pattern showed no impurities of Sm, Cr, or their compounds in the samples, indicating that Sm+3 and Cr+3 had been replaced in the BFO structure. The XRD pattern of the Bi 0. 90 Sm 0.1 Fe 0.97 Cr 0.03 O 3 @PANI core-shell shows all peaks of Bi 0. 90 Sm 0.1 Fe 0.97 Cr 0.03 O 3 composition with lower intensity, as a result, the Bi 0. 90 Sm 0.1 Fe 0.97 Cr 0.03 O 3 composition is phase single. This lower intensity is attributed to the presence of amorphous polyaniline in the core-shell structure. Since there is in the FT-IR spectrum of the Bi 0. 90 Sm 0.1 Fe 0.97 Cr 0.03 O 3 @PANI core-shell, characteristic peaks of both polyaniline and bismuth ferrite simultaneously so, the FT-IR spectrum of the Bi 0. 90 Sm 0.1 Fe 0.97 Cr 0.03 O 3 @PANI core-shell is a perovskite structure. The synthesized samples exhibit weak magnetic properties and behave as a paramagnetic material. The absorption capability of core-shell compared to core nanoparticles has increased in the visible region, and this enhancement is attributed to the influence of the presence of polyaniline. All the peaks in the UV–visible absorption spectrum characterize the nano-sized bismuth ferrite and polyaniline in the UV–visible spectrum of the core-shell. The intensity of the photoluminescence spectrum in the doped sample is significantly higher compared to the core-shell sample. This indicates a much faster recombination rate in the doped nanoparticles compared to the core-shell nanocomposite. The doping of the core with Cr and Sm elements, as well as the coating of the core with a polymeric shell, has led to an increase in the degradation rate of the red dye. We also found that shell thickness plays a vital role in dye degradation efficiency and photocatalytic performance. The Bi 0. 90 Sm 0.1 Fe 0.97 Cr 0.03 O 3 @PANI core-shell exhibits significant photocatalytic activity under visible light. The photocatalytic studies show that the best sample is Bi 0.9 Sm 0.1 Fe 0.97 Cr 0.03 O 3 @PANI core-shell with aniline concentration of 0.2 mL and a pH = 2 which was able to destroy 100 % of Congo red dye molecules. [ABSTRACT FROM AUTHOR]

Cr-doped Bi0.9La0.1Fe1-xCrxO3 with x = 0, 0.05, 0.10, 0.15, and 0.20 is fabricated by the sol-gel auto-combustion. The rhombohedral phase of pure and doped bismuth ferrite is confirmed during structural analysis. The structural parameters are further refined using X'pert High score plus by calculating the atomic positions and different profile factors which assured the reliability of the structural data. As Cr content is increased, it results the better crystallinity with uniform distribution of multi-shape grains. The size of grains varied which affected the microstructural characteristics of the parent compositions. The presence of constituent elements with a stoichiometric ratio is established by elemental analysis which guarantees elemental purity of prepared samples. The introduction of La followed by increasing contents of Cr in the parent composition improved the magnetic response. Ferroelectric analysis revealed that both saturation and remanent polarizations are increased with increasing doping levels. The calculation of recoverable and energy loss density ensured that the parent composition was more suitable for the energy storage devices. The multiferroic properties of synthesized samples are comprehensively explored to evaluate the worth of these materials for futuristic energy storage and multistate devices. [ABSTRACT FROM AUTHOR]

This study aims to enhance the multiferroic properties of bismuth ferrite (BFO) by investigating the effects of substitution with erbium (Er) on the material's structural, optical, and magnetic characteristics. Er-substituted bismuth ferrite (Bi1−xErxFeO3) (x = 0, 0.04, 0.08, 0.12, 0.16) nanoparticles (NPs) were synthesized via the very cost-effective Pechini modified sol–gel method followed by auto-combustion. X-ray diffraction (XRD) patterns confirmed the crystallinity, structure, and purity of the phase, revealing the formation of single-phase materials. The bond structure of the prepared samples was examined using Fourier transform infrared (FTIR) spectroscopy, confirming the significant stretching and bending of bonds of perovskites. Electron paramagnetic resonance (EPR) findings suggested a broadening of the signal as well as a shift of the center of resonance to lower fields. The experimental findings revealed that Er doping has a significant effect on the magnetic ordering and saturation magnetization of BiFeO3. In addition, UV–Vis spectroscopy demonstrated that the energy bandgap in the prepared samples varies from 2.13 eV to 1.71 eV. This research contributes to an understanding of the enhanced structural, magnetic, and optical properties of Er-substituted BFO nanoparticles, which is useful for designing and developing multiferroic materials with enhanced magnetic functionality for next-generation magnetoelectric devices, optoelectronic devices, and photocatalysts. [ABSTRACT FROM AUTHOR]

Bismuth ferrite (BiFeO3) nanoparticles were synthesized using sol‐gel method and annealed at 450 °C, 550 °C, 650 °C, and 750 °C for 2 hours. The role of annealing temperature on structural, optical, magnetic, and dielectric properties of BiFeO3 nanoparticles was studied. XRD patterns of BiFeO3 nanoparticles confirm the rhombohedral structure with a mean crystallite size of 40 nm. The optical bandgap of the BiFeO3 nanoparticles increased from 1.9 eV to 2.02 eV with annealing temperature. From photoluminescence spectra, it was observed that the BiFeO3 nanoparticles showed a clear emission peak at 565 nm and its intensity decreased with annealing temperature. Magnetic properties of the BiFeO3 nanoparticles were studied at room temperature and different magnetic behaviours were found in BiFeO3 nanoparticles. The BiFeO3 nanoparticles exhibited ferromagnetism at low annealing temperatures and diamagnetic nature at high annealing temperatures. The AC conductivity studies showed that BiFeO3 nanoparticles possess a dielectric constant of 170 with the least dielectric loss. The BiFeO3 nanoparticles annealed at 750 °C were studied for photocatalytic properties and showed good photocatalytic activity in the visible region. A prominent absorption peak at 663 nm in absorption spectra due to MB and it confirm the utility of BFO as photocatalyst applications. [ABSTRACT FROM AUTHOR]

Semiconductor hollow spheres have garnered significant attention in recent years due to their unique structural properties and enhanced surface area, which are advantageous for various applications in catalysis, energy storage, and sensing. The present study explores the surfactant-assisted synthesis of bismuth ferrite (BiFeO3) hollow spheres, emphasizing their enhanced visible-light photocatalytic activity. Utilizing a novel, facile, two-step evaporation-induced self-assembly (EISA) approach, monodisperse BiFeO3 hollow spheres were synthesized with a narrow particle size distribution. The synthesis involved Bi/Fe citrate complexes as precursors and the triblock copolymer Pluronic P123 as a soft template. The BiFeO3 hollow spheres demonstrated outstanding photocatalytic performance in degrading the emerging pollutants Rhodamine B and metronidazole under visible-light irradiation (100% degradation of Rhodamine B in <140 min and of metronidazole in 240 min). The active species in the photocatalytic process were identified through trapping experiments, providing crucial insights into the mechanisms and efficiency of semiconductor hollow spheres. The findings suggest that the unique structural features of BiFeO3 hollow spheres, combined with their excellent optical properties, make them promising candidates for photocatalytic applications. [ABSTRACT FROM AUTHOR]

A sol-gel method was employed to synthesize phase-pure (1-x)BiFeO3-xBi(Mn0.5Ti0.5)O3 (abbreviated as BFO-xBMT, x = 0–0.10) multiferroic ferrites. The investigation focused on the structure, optical, and magnetic properties, and their dependence on composition. X-ray diffraction analysis (XRD) revealed a single phase rhombohedral structure for BiFeO3 (BFO), with distinct double peaks (104)/(110) and (006)/(202) at diffraction angles 2θ ∼ 32.0° and 39.5°. As the content of Bi(Mn0.5Ti0.5)O3 (BMT) increased, a structural transition from rhombohedral (R3c) to pseudo-cubic (Pm3m) phase was observed. Doping with BMT led to a decrease in particle size. The band gap (Eg) of BFO-xBMT materials exhibited a slight increase from 1.99 eV in BFO to 2.18 eV in the BFO-0.10BMT composition. The introduction of BMT resulted in a significantly enhanced room temperature ferromagnetism in BiFeO3, with the maximum magnetic moment doubling to around 5.7 emu/g for the BFO-0.04BMT solid solution. This improvement is attributed to the addition of BMT inducing intrinsic strain in the crystal lattice, suppressing the intrinsic helical spin structure of BFO, and thus enhancing its latent magnetic potential. The research demonstrated the substantial influence of BMT perovskite on the structure, optical, and magnetic properties of BFO materials. Overall, the results suggest that the BFO-xBMT multiferroic ferrites with optimal composition hold promise for use in multifunctional devices. [ABSTRACT FROM AUTHOR]

BiFeO3 (BFO), Mn-doped-BFO (BFMO), Ti-doped-BFO (BFTO), and (Mn,Ti)-codoped-BFO (BFMTO) thin films are fabricated on the Pt/TiO2/SiO2/Si substrates via a sol–gel method combined with spin-coating and the subsequent layer-by-layer annealing technique. Compared with BFO film, the BFMTO film exhibits the lowest leakage current density (∼ 1 0 − 4 A/cm2@290 kV/cm). Notably, the polarization–electric field (P–E) loop of BFMTO film exhibits a positive displacement along the x-axis due to the existence of internal bias electric field, which is in agreement with the results of the PFM phase and amplitude curves. Especially, a very prominent inverse piezoelectric constant of d 3 3 ∼ 1 6 0 pm/V was obtained, which overcomes other related thin films. The internal bias electric field of BFMTO film can be caused by the different work functions of the thin film and the bottom electrode, accumulation of oxygen vacancies and the formation of defect dipoles. Besides, the internal bias electric field of BFMTO film has a good stability at the same electric field after experiencing the test cycle from low electric field to high electric field (400–1900 kV/cm). These results indicate that self-polarized BFMTO film can be integrated to devices without additional polarization process, and have a wide range of application in microelectromechanical systems. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Increasing demand for functional materials crucial for advancing new technologies has motivated significant scientific and industrial research efforts. High-entropy materials (HEMs), with tunable properties, are gaining attention for their use in high-frequency transformers, microwave devices, multiferroics, and high-density magnetic memory components. The initial exploration of HEMs started with high-entropy alloys (HASs), such as CrMnFeCoNi, CuCoNiCrAlxFe, and AlCoCrTiZn and paved the way for a multitude of HEM variations, including oxides, oxyfluorides, borides, carbides, nitrides, sulfides, and phosphides. In this study, we fabricated the high-entropy oxide (HEO) compound B i 0.5 L a 0.1 I n 0.1 Y 0.1 N d 0.1 G d 0.1 F e O 3 through the solid-state synthesis method. Magnetic measurements at 300 K show ferromagnetic behavior with significant coercivity. At the same time, this novel composition exhibits excellent dielectric properties and shows potential for electronic applications demonstrating that a high-entropy approach can expand the compositional range of rare earth multiferroics and improve the multifunctional properties in multiferroic applications. [ABSTRACT FROM AUTHOR]

This work presents a novel paradigm for upconversion‐assisted ferroelectric photovoltaic devices. The system comprises a ferroelectric active layer (BiFeO3), an upconverter layer (Yb; Er‐doped ZnO), a conductive ITO‐coated glass substrate, and a reflective coating (Al) at the rear end of the glass substrate. The photovoltaic efficiency of the single‐layer BFO was found to be 0.71%. With the prescribed device model, the total solar efficiency of BiFeO3 improved significantly and touched solar conversion efficiency of 2.21%. This model's projection widens the future perspectives of device performance in emerging photovoltaic technology, mainly perovskite‐based solar cells. [ABSTRACT FROM AUTHOR]

Epitaxial films of multiferroic BiFe 1 − x Co x O 3 (BFCO) with 0 ≤ x ≤ 0.35 are grown on (001)-oriented SrTiO 3 and SrRuO 3 buffered SrTiO 3 substrates using the pulsed laser deposition technique. The effect of structural transformation from rhombohedral to tetragonal phase with increasing cobalt substitution on the magnetic, electrical, and piezo-/ferroelectric properties is investigated. Piezoresponse force microscopy is used to quantify the coercive voltage from the phase hysteresis loops for different thickness films to investigate the semi-empirical Kay–Dunn scaling law with varying cobalt concentrations. For the rhombohedral structure, a reduction of the coercive voltage is observed with increasing substitution of Fe by Co. The coercive voltage of a 10 nm BFCO (x = 0.35) film is found to be 0.63 V, which is 67% lower than that of a pure BiFeO 3 (BFO) (1.9 V) film of the same thickness. Cobalt substitution also leads to changes in the magnetic and electrical properties due to modification of spin ordering and reduction of the bandgap, respectively. Further, to validate the experimental results, we have performed theoretical calculations using density functional theory. The theoretical results indicate a reduction in unit cell volume and enhancement in net magnetization can be achieved with cobalt substitution, in agreement with experimental results. Partial Co substitution can, thus, provide a pathway to realize BFO-based nonvolatile magnetoelectric devices with reduced operating voltage. [ABSTRACT FROM AUTHOR]

Supercapacitors (SCs) have attracted significant attention in the realm of energy storage devices due to their exceptional features, such as enhanced charge storage capacity, fast charge‐discharge rates, and high power density. The emergence of cost‐effective and highly productive SCs is a topic of interest among industrial and scientific communities. Ferrites with a perovskite crystal structure are often considered excellent electrode materials due to their intrinsic properties, affordability, low environmental impact, and widespread availability. An in‐depth investigation of perovskite ferrites in the context of SCs is necessary to advance the understanding of these materials. The techniques used in the synthesis of ABO3‐type perovskite bismuth ferrite materials are comprehensively reviewed in this review. The review starts by analyzing various types of SCs classified based on their electrode materials. The review provides a comprehensive understanding of the design and functionality of these devices, serving as an important source of inspiration for new methods of synthesis and fabrication methodologies that aim to produce environmentally friendly SCs. [ABSTRACT FROM AUTHOR]

Plasmonics is an emerging and very advantageous technology which provides high speed and tiny size devices for fulfilling the demand of today's high-speed world. SPPs are the information carrying elements in plasmonics, which are capable of breaking the diffraction limit. Plasmonics technology has shown its application in uncountable nanophotonic applications like switching, filtering, light modulation, sensing and in many more fields. Modulators are the key components of integrated photonic system. Various modulators which work on different effects are discussed in this study for providing a universal idea of modulators to researchers. Some useful plasmonic active materials are also discussed which are used in most of plasmonic modulators and other active devices. Previously, many researchers have worked on many kinds of modulators and switches, which operate on different kind of operating principles. For providing an overview about plasmonic modulators, their classification and their operation, we have discussed the state of art of some previously introduced modulators and switches which operates on electro-refractive effects and include electro-optic effect, Pockels effect, free charge carrier dispersion effect, phase change effect, elasto-optic effect, magneto-optic effect, and thermo-optic effect. Instead of different effects used in plasmonic switches and modulators different active materials like liquid crystals, graphene, vanadium di-oxide, chalcogenides, polymers, indium tin oxide, bismuth ferrite, barium titanate, and lithium niobate are also explained with their properties. Additionally, we also compared modulators based on different effects in terms of their design characteristics and performances. [ABSTRACT FROM AUTHOR]

Bismuth ferrite (BiFeO3) thin films were epitaxially grown on (110)- and (001)-oriented NdGaO3 single crystal orthorhombic substrates by pulsed laser deposition. The films grown on NdGaO3(110) are fully strained and show two ferroelectric variants that arrange in a stripe domain pattern with 71° domain walls, as revealed by piezoresponse force microscopy. We explored their antiferromagnetic textures using scanning nitrogen-vacancy magnetometry. Surprisingly given the large compressive strain state, the films still show a spin cycloid, resulting in a periodic zig-zag magnetic pattern due to the two ferroelastic variants. The films grown on NdGaO3(001) are also fully strained, but the (001) orthorhombic substrate imposes a strongly anisotropic in-plane strain. As a consequence, the ferroelectric polarization exhibits a uniaxial in-plane component, parallel to the b-axis of the substrate. The ferroelectric domain pattern consists of 109° charged domain walls between the two selected ferroelastic variants. This anisotropic strain impacts the magnetic state of BiFeO3 and leads to a simpler spin texture defined by a single propagation vector for the spin cycloid. In both cases, electric-field control of ferroelectric domains tends to favor a transition to a canted antiferromagnetic order. These results reveal that the cycloidal structure of BiFeO3 can undergo large compressive strain and open further electrical means to tune the magnetic state of this room-temperature multiferroic compound. [ABSTRACT FROM AUTHOR]

Structural and electrochemical properties of bismuth ferrite nanostructures produced by pulsed laser deposition with various morphologies are reported. The nanostructures are also explored as electrode materials for high-performance supercapacitors. Scanning electron microscopy images revealed that various bismuth ferrite morphologies were produced by varying the background pressure (10−6, 0.01, 0.10, 0.25, 0.50, 1.0, 2.0 and 4.0 Torr) in the deposition chamber and submitting them to a thermal treatment after deposition at 500 ◦C. The as-deposited bismuth ferrite nanostructures range from very compact thin-film (10−6, 0.01, 0.10 Torr), to clustered nanoparticles (0.25, 0.50, 1.0 Torr), to very dispersed arrangement of nanoparticles (2.0 and 4.0 Torr). The electrochemical characteristic of the electrodes was investigated through cyclic voltammetry process. The increase in the specific surface area of the nanostructures as background pressure in the chamber increases does not lead to an increase in interfacial capacitance. This is likely due to the wakening of electrical contact between nanoparticles with increasing porosity of the nanostructures. The thermal treatment increased the contact between nanoparticles, which caused an increase in the interfacial capacitance of the nanostructure deposited under high background pressure in the chamber. [ABSTRACT FROM AUTHOR]

Herein, heavy rare‐earth substituted bismuth ferrite thin films were prepared using a low‐temperature sol–gel‐assisted spin coating method. The substitution of heavy rare‐earth ions for Bi3+ leads to structural transformation from rhombohedral (R3c) for x = 0.05 to orthorhombic (Pnma) symmetry for x = 0.05, which was found to have a great effect on the surface morphology, optical band‐gap energy, and photocatalytic activity of a BiFeO3(BFO) thin film. Moreover, the optical properties of prepared films were investigated via UV–visible spectroscopy. For all samples, the bandgap energy values were between 1.18 and 1.65 eV. Moreover, the refractive index and extinction coefficient of samples were about 1.14–1.40 and 0.1–0.6, respectively. Photocatalytic properties of the samples were investigated by measuring the degradation of methylene blue dye under simulated solar irradiation. We found that the heavy rare‐earth substituted BFO thin films have better photocatalytic activity compared to pure BiFeO3 thin film. It was observed that prepared thin films could remove between 37.18% and 77.24% of dye after 180 min irradiation. This study confirms that prepared thin films are a suitable candidate for photocatalytic applications. [ABSTRACT FROM AUTHOR]

BiFeO 3 is a promising multiferroic material for versatile device applications due to its co-existence of magnetic (i.e., antiferromagnetic) and ferroelectric ordering at room temperature. While its functional properties have been extensively investigated, the exploration of its mechanical behavior was limited mostly to the thin-film form of BiFeO 3. In this work, we conducted in situ micropillar compression experiments to investigate the deformation behavior of La-doped BiFeO 3 (La-BFO) samples processed by both conventional and flash sintering methods. The conventionally sintered La-BFO exhibited limited deformability at room temperature and 450 °C. In contrast, the deformability of the flash-sintered La-BFO specimens was substantially improved by nearly 100% at both testing temperatures. Detailed post-mortem studies suggest that preexisting dislocations and wide anti-phase boundaries introduced during flash sintering can toughen flash-sintered La-BFO by easing dislocation migration and ferroelastic domain switching. This study provides a fresh perspective to design an advanced multifunctional system with improved mechanical properties. • Flash sintering introduced high population of pre-existing dislocations and anti-phase boundaries into La-BFO. • The flash sintered La-BFO deformed at room temperature exhibited an over 100% deformability enhancement. • At 450 °C, the flash-sintered La-BFO outperformed the conventionally sintered counterpart by showing plastic deformability. [ABSTRACT FROM AUTHOR]

This study explores the impact of nickel (Ni) doping bismuth ferrite (BiFeO3) thin film synthesis by spray pyrolysis method. The structural and morphological study shows that the thin films are slightly amorphous with granular morphology. Investigated the supercapacitive behavior of synthesized material by using cyclic voltammetry, galvanostatic charge‐discharge, and electrochemical impedance spectroscopy. The thin films synthesized are capable of storing a 253.31 F/g capacitance at a 10 mV/s scan rate and by introducing nickel into the synthesis process, we obtained 312.12 F/g capacitance at a 10 mV/s scan rate. The material shows good cyclic stability after 91000 cycles. It is also observed that no structural and morphological changes were made by doping Ni into BiFeO3 thin films. The significant improvement in capacitance was displayed by Ni doping into BiFeO3 obtained via spray pyrolysis methods indicating its potential for use in supercapacitor applications. [ABSTRACT FROM AUTHOR]

The need to develop advanced wastewater treatment techniques and their use has become a priority, the main goal being the efficient removal of pollutants, especially those of organic origin. This study presents the photo-degradation of a pharmaceutical wastewater containing Kabi cytarabine, using ultraviolet (UV) radiation, and a synthesized catalyst, a composite based on bismuth and iron oxides (BFO). The size of the bandgap was determined by UV spectroscopy, having a value of 2.27 eV. The specific surface was determined using the BET method, having a value of 0.7 m2 g−1. The material studied for the photo-degradation of cytarabine presents a remarkable photo-degradation efficiency of 97.9% for an initial concentration 0f 10 mg/L cytarabine Kabi when 0.15 g of material was used, during 120 min of interaction with UV radiation at 3 cm from the irradiation source. The material withstands five photo-degradation cycles with good results. At the same time, through this study, it was possible to establish that pyrimidine derivatives could be able to combat infections caused by Escherichia coli and Candida parapsilosis. [ABSTRACT FROM AUTHOR]

This work reports solvothermal synthesized multiferroic bismuth ferrite nanoparticles (BFO) supported PVDF-HFP membrane (PBF) for the degradation of organic pollutants (Rhodamine B). The bismuth ferrite NPs have been incorporated into the PVDF-HFP matrix in four different concentrations (PBF0, PBF2.5, PBF7.5, PBF11). The BFO perovskite crystals have successfully enhanced the piezoelectric activity of the PVDF-HFP membrane and have been found to be highest for PBF7.5, which further results in the generation of reactive radicals (ROS). These ROS have reacted with dye solutions and enhanced the piezocatalytic activity of the synthesized material. The catalytic efficiency of this membrane is found to be the highest (∼95.2 %) for PBF7.5 with promisingly rapid degradation rates (in 40 min). Furthermore, the BFO-PVDF-HFP membrane successfully extracts from the solutions which make it reusable in industries. Moreover, this multifunctional free-standing membrane could be a possible alternative for future wastewater treatment plants. [Display omitted] [ABSTRACT FROM AUTHOR]

The exploration of multiferroic materials and their interaction with light at the nanoscale presents a captivating frontier in materials science. Bismuth Ferrite (BiFeO3, BFO), a standout among these materials, exhibits room-temperature ferroelectric and antiferromagnetic behaviour and magnetoelectric coupling. Of particular interest is the phenomenon of photostriction, the light-induced deformation of crystal structures, which enhances the prospect for device functionality based on these materials. Understanding and harnessing multiferroic phenomena holds significant promise in various technological applications, from optoelectronics to energy storage. The orientation of the ferroelectric axis is an important design parameter for devices formed from multiferroic materials. Determining its orientation in the laboratory frame of reference usually requires knowing multiple wavevector transfer (Q-Vector) directions, which can be challenging to establish due to the need for extensive reciprocal-space searches. Our study demonstrates a method to identify the ferroelectric axis orientation using Bragg Coherent X-ray Diffraction Imaging (BCDI) measurements at a single Q-vector direction. This method involves applying photostriction-inducing laser illumination across various laser polarisations. Our findings reveal that photostriction primarily occurs as a surface phenomenon at the nanoscale. Moreover, a photo-induced crystal length change ranging from 30 to 60 nm was observed, consistent with earlier findings on bulk material. [ABSTRACT FROM AUTHOR]

The current work discusses the radiation attenuation capability and different shielding characteristics of different mortar samples. The samples were prepared by replacing different percentages of fine aggregate with iron filling and replacing different percentages of hydrated lime with Bi2O3 (0–50 wt.%). The prepared mortar samples are coded as CHBFX where X = 0, 10, 30, and 50 wt.%. The mass and linear attenuation coefficient was determined experimentally using a narrow beam technique, where a high purity germanium detector, and different point gamma-ray sources (such as Am-241, Cs-137, and Co-60). The linear attenuation coefficient was also calculated using the Monte-Carlo simulation code and the online Phy-X/PSD software. The comparison of the three methods showed a good agreement in the results. The linear attenuation coefficient drops from 19.821 to 0.053 cm−1 for CHBF0, from 27.496 to 0.057 cm−1 for CHBF10, from 42.351 to 0.064 cm−1 for CHBF30, and from 55.068 to 0.071 cm−1 for CHBF50 at photon energy range from 0.015 to 15 MeV. The half-value layer thickness, tenth-value layer thickness, and mean free path of the prepared mortar composites were also calculated photon energy ranged from 0.015 to 15 MeV. The fast neutron removal cross-section of the prepared CHBFX mortar samples have values of 0.096 cm−1, 0.098 cm−1, 0.103 cm−1, and 0.107 cm−1 for the mortar samples CHBF0, CHBF10, CHBF30, and CHBF50, respectively. The results showed that the mortar sample with the highest iron filing concentration, CHBF50, provides the best protection against gamma rays and fast neutrons which could be used in the nuclear and medical fields. [ABSTRACT FROM AUTHOR]

Bismuth ferrite BiFeO3 (BFO)-based ferroelectrics have great potential as inorganic perovskite-like oxides for future solar cells applications due to their unique physical properties. In this work, La and Mn co-doped BFO thin films with compositions Bi0.9La0.1(Fe1−xMnx)O3 (x = 0, 0.05, 0.1, 0.15) (denoted as BLF, BLFM5, BLFM10, BLFM15, respectively) were prepared via a sol–gel technique on indium tin oxide (ITO) glass. All the films are monophasic, showing good crystallinity. The optical bandgap Eg was found to decrease monotonously with an increase in the Mn doping amount. Compared with other compositions, the BLFM5 sample exhibits a better crystallinity and less oxygen vacancies as indicated by XRD and XPS measurements, thereby achieving a better J–V performance. Based on BLFM5 as the light absorbing layer, the ITO/ZnO/BLFM5/Pt and ITO/ZnO/BLFM5/NiO/Pt heterostructure devices were designed and characterized. It was found that the introduction of the ZnO layer increases both the open circuit voltage (Voc) and the short circuit current density (Jsc) with Voc = 90.2 mV and Jsc = 6.90 μA/cm2 for the Pt/ BLFM5/ZnO/ITO device. However, the insertion of the NiO layer reduces both Voc and Jsc, which is attributed to the weakened built-in electric field at the NiO/BLFM5 interface. [ABSTRACT FROM AUTHOR]