Search

Clavibacter michiganensis subsp. michiganensis (Cmm) and C. michiganensis subsp. capsici (Cmc) are phytopathogenic bacteria that cause bacterial canker disease in tomatoes and peppers, respectively. Bacterial canker disease poses serious challenges to solanaceous crops, causing significant yield losses and economic costs. Effective management necessitates the development of sustainable control strategies employing nanobiotechnology. In this study, the antibacterial effects of four Aspergillus sojae -mediated nanoformulations, including cobalt oxide nanoparticles (Co 3 O 4 NPs), zinc oxide nanoparticles (ZnO NPs), cobalt ferrite nanoparticles (CoFe 2 O 4 NPs), and CoFe 2 O 4 /functionalized multi-walled carbon nanotube (fMWCNT) bionanocomposite, were evaluated against Cmm and Cmc. The diameters of the zone of inhibition of A. sojae -mediated Co 3 O 4 NPs, ZnO NPs, CoFe 2 O 4 NPs, and CoFe 2 O 4 /fMWCNT bionanocomposite against Cmm and Cmc were 23.60 mm, 22.09 mm, 27.65 mm, 22.51 mm, and 19.33 mm, 17.66 mm, 21.64 mm, 18.77 mm, respectively. The broth microdilution assay was conducted to determine the minimal inhibitory and bactericidal concentrations. The MICs of Co 3 O 4 NPs, ZnO NPs, CoFe 2 O 4 NPs, and CoFe 2 O 4 /fMWCNT bionanocomposite against Cmm were 2.50 mg/mL, 1.25 mg/mL, 2.50 mg/mL, and 2.50 mg/mL, respectively. While, their respective MBCs against Cmm were 5.00 mg/mL, 2.50 mg/mL, 5.00 mg/mL, and 5.00 mg/mL. The respective MICs of Co 3 O 4 NPs, ZnO NPs, CoFe 2 O 4 NPs, and CoFe 2 O 4 /fMWCNT bionanocomposite against Cmc were 2.50 mg/mL, 1.25 mg/mL, 5.00 mg/mL, and 5.00 mg/mL. While, their respective MBCs against Cmc were 5.00 mg/mL, 2.50 mg/mL, 10.00 mg/mL, and 10.00 mg/mL. The morphological and ultrastructural changes of Cmm and Cmc cells were observed using field-emission scanning and transmission electron microscopy before and after treatment with sub-minimal inhibitory concentrations of the nanoformulations. Nanoformulation-treated bacterial cells became deformed and disrupted, displaying pits, deep cavities, and groove-like structures. The cell membrane detached from the bacterial cell wall, electron-dense particles accumulated in the cytoplasm, cellular components disintegrated, and the cells were lysed. Direct physical interactions between the prepared nanoformulations with Cmm and Cmc cells might be the major mechanism for their antibacterial potency. Further research is required for the in vivo application of the mycosynthesized nanoformulations as countermeasures to combat bacterial phytopathogens. [Display omitted] • A. sojae -mediated nanoformulations exhibited significant antibacterial potential against phytopathogens. • Assessment of morphological and ultrastructural changes using FESEM and TEM. • Elucidation of plausible antibacterial mechanism of A. sojae -mediated nanoformulations. • Mycosynthesis of nanoformulations is a green approach for plant disease management. [ABSTRACT FROM AUTHOR]

In this work, the magnetic hysteresis loop of the polyvinyl alcohol@CoFe2O4 nanocomposite has been predicted and simulated using a deep artificial neural network (ANN) and Monte Carlo (MC) methods. To increase the capability of the traditional neural networks in modeling and forecasting problems, the proposed deep ANN has two hidden layers that benefit from deep learning techniques to overcome well-known issues such as overfitting and gradient vanishing. The deep ANN predicted results were compared with the simulated and experimental hysteresis loops of the synthesized polyvinyl alcohol@CoFe2O4 nanocomposites obtained from the vibrating sample magnetometer and MC method. The interaction between polymer and nanoparticles, their structure, and morphology were analyzed employing Fourier transform infrared spectroscopy, X-ray diffraction spectroscopy, and field emission scanning electron microscopy. Comparison between the hysteresis loops revealed that the deep ANN method that has been trained with the previous published data was successful in the prediction of the shape and coercive field of particles in a polymer matrix relative to the MC method, which considered only the uniaxial anisotropy and Zeeman energy of the nanoparticles. The coercivity and remanence magnetization measured with the accuracy of about 93.33% and 62.23% for deep ANN method and 80.76% and 66.66% for MC method, respectively. [ABSTRACT FROM AUTHOR]

Nanoferrites of (Mn1-xMgx)0.8Li0.1Fe2.1O4 (x: 0–1.0, step 0.2) were synthesized by the sol–gel autocombustion method. The structural properties of the samples were characterized by X-ray diffraction, particle size analysis, transmission electron microscopy, and Fourier transform infrared spectroscopy. The X-ray diffraction patterns for the samples establish the nanoscale (38–54 nm) pure-phase spinel cubic structure (Fd- 3 ̅ m). Also, the particle size analysis results demonstrate the narrow distribution of their particle sizes, which range from 10 to 33 nm. The impact of Mg2+ ion concentration on the thermal, elastic, magnetic, and optical properties of these samples was studied. The saturation magnetization decreases from 56.9 to 31.1 emu/g, and the coercivity increases from 65.8 to 106.8G with the addition of Mg2+ ions, showing thin S-shaped hysteresis loops revealing the samples' soft magnetic behavior. Thermal results indicate that these samples are interesting candidates for thermoelectric applications due to their noticeably lower thermal conductivity, which ranges from 0.3572 to 0.5881 W/mK. The optical band gap values determined by using ultraviolet-visible diffuse reflectance spectroscopy range from 5.11 to 5.25 eV, where quantum confinement for crystallite size triggers a larger band gap. As the concentration of Mg2+ ions increases, their ability to degrade methyl green dye under ultraviolet radiation for 100 min rises from 13.6 to 61.1% with the addition of H2O2, an indication of their photocatalytic activity. Moreover, the optimum ferrite sample, Mn0.4Mg0.4Li0.1Fe2.1O4, maintained its photocatalytic efficiency for at least six reaction cycles. Highlights: The (MgxMn1−x)0.8 Li0.1 Fe2.1 O4 was prepared by the citrate precursor method. XRD, PSA and TEM results confirm the nanostructure of the Mn-Mg-Li ferrite samples. Soft magnetic samples are nominees for switching and memory core applications. Lower ks indicates the samples are candidates for thermoelectric applications. Photodegradation efficiency of the samples for MG dye enhanced from 13.6 to 61.1%. [ABSTRACT FROM AUTHOR]

Seven cubic spinel ferrite nanoparticles were successfully synthesized through the co-precipitation method. These nanoparticles include Fe3O4, Zn0.4Fe0.62+Fe23+O4, Mn0.4Fe0.62+Fe23+O4, Zn0.6Mn0.4Fe0.42+Fe1.63+O4, Zn0.4Mn0.6Fe0.42+Fe1.63+O4, Zn0.4Mn0.4Fe0.22+Fe23+O4, and Zn0.4Mn0.4Fe0.42+Fe1.83+O4. The Rietveld method was used to analyze X-ray diffraction data, confirming that all samples have a single-phase cubic spinel structure. The presence of zinc and manganese ions in magnetite lattice leads to changes in lattice parameters and crystallite size, resulting in a range of 7–12 nm crystallite sizes. Fourier transform infrared spectroscopy (FT-IR) analysis of nanoparticles reveals two significant adsorption peaks at 560-576 cm−1 and 437-449 cm−1, corresponding to metal ion stretching vibrations at tetrahedral and octahedral sites. The X-ray photoelectron spectroscopy (XPS) analysis revealed the presence of iron, zinc, and manganese in various oxidation states. Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) images showed spherical, agglomerated nanoparticles. The study confirmed the elemental composition and mapping images of prepared samples using energy-dispersive X-ray spectroscopy (EDS). The magnetic properties of the synthesized nanoparticles were meticulously examined utilizing a vibrating sample magnetometer (VSM) at room temperature. A direct correlation is established between the structural alterations induced by Zn2+/Mn2+ and their subsequent effects on magnetic characteristics, specifically through the reallocation of cations and the mechanisms of electron hopping occurring at the B-sites. The structural modifications result in enhanced superparamagnetic behavior, exhibiting saturation magnetization values between 46.01 and 69.38 emu/g. The sustainable characteristics of these materials render them highly viable options for applications in environmental remediation and green technology.

In this research work, we have incorporated paramagnetic Cu2+ and diamagnetic Cd2+ cations in spinel ferrites. By adjusting the concentrations of Cu2+ and Cd2+, it is possible to achieve a balance between enhanced electrical conductivity, desired magnetic properties, and suitable structural characteristics for applications in high-frequency devices, magnetic sensors, and electromagnetic interference (EMI) suppression through a synergistic effect. The sol-gel auto-combustion method was employed to synthesize Cd²⁺ and Cu²⁺ co-doped Ni0.5Zn0.5-x-yCuxCdyFe2O4 (x = y = 0.0, 0.05, 0.1, 0.15, 0.2) ferrite nanoparticles. Structural, morphological-compositional, functional, and magnetic properties of the nanoparticles were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy with energy dispersive spectroscopy (FESEM-EDS), Fourier-transform infrared spectroscopy (FT-IR), and vibrating sample magnetometry (VSM). The XRD results confirmed the single-phase spinel structures with lattice constants increasing with higher dopant concentrations. The average crystallite sizes were found in the range of 38.14 - 42.68 nm and lattice constants in the range of 8.389 - 8.423 Å. Morphological analysis revealed agglomeration, consistent with the stoichiometric proportions during synthesis. There is a decreasing trend in nanograin sizes in the range of 40 to 73 nm with the concentration. FT-IR spectra verified the spinel structures through characteristic absorption bands around 600 cm⁻¹ and 400 cm⁻¹. Magnetic measurements indicated a decrease in saturation magnetization with increasing dopant levels indicating their potential use in electromagnetic wave absorption and magnetic memory devices.

Textile dyes like rose bengal (RB) are infamous sources of pollution in the environment due to their persistence and toxicity. In this study, we explored the use of molybdic acid (MA)-functionalized iron oxide magnetic nanoparticles (MNPs) for the removal of RB dye from wastewater through the adsorption process. Nanoparticles were synthesized using a facile and cost-effective precipitation method and well-characterized for structural, magnetic and surface behaviours using XRD, FTIR, XPS, BET, HRTEM and VSM techniques. Adsorption properties of the nanoparticles were evaluated by varying the parameters, such as initial dye concentration, pH and contact time. Results showed that the MNPs had a high adsorption capacity for RB dye removal at 4 × 10−5 M concentration with an uptake of up to 89% within 100 min. At the optimal operation conditions, MA-functionalized Fe3O4 nanoparticles exhibited a maximum adsorption capacity of 60 mg g−1 for RB dye, which is significant in comparison with the reported literature. Isotherm studies indicated that the adsorption process was spontaneous, exothermic and favoured at room temperature. It is also deduced that the process that occurred was physisorption, primarily the result of electrostatic attractions. Overall, this study suggests that MA-functionalized iron oxide nanoparticles have the potential to be an efficient material for the removal of textile dyes from wastewater. Molybdic acid functionalized Fe3O4 nanoparticles prepared through facile co-precipitation method shows intriguing electrostatic interaction with anionic rose Bengal dye. The interaction gets stronger at low pH due to extremely protonated surface of the adsorbent. [ABSTRACT FROM AUTHOR]

In this study, NiFe2O4, ZnFe2O4, and MgFe2O4 catalysts are utilized to decompose plastic into hydrogen gas, liquids, and carbon nanotubes. Ferrite nanoparticles worked as a catalyst and heat susceptors for microwaves. MgFe2O4 catalyst resulted in highly structured carbon residue with fewer impurities than other catalysts. The oil yield of 13.5, 14, and 9.5 wt. % was obtained with NiFe2O4, ZnFe2O4, and MgFe2O4, respectively. Similarly, gas evolution was about 14, 13, and 12.5 wt. %, respectively. MgFe2O4 displayed superior H2 production efficiency of 90 % compared to the other two catalysts. These findings suggest high activity of MgFe2O4 catalyst compared to NiFe2O4 and ZnFe2O4 catalysts. This catalyst also showed stronger magnetic characteristics and reactivity. [ABSTRACT FROM AUTHOR]

This work explored the versatility of nanocrystalline Sm-doped Cu–Ni spinel ferrites in different applications, with a special emphasis on hyperthermia and photocatalytic activities. By incorporating Sm dopants at varied percentages in nanosized Cu–Ni spinel ferrites, the magnetic, electrical, and structural properties of the host ferrites were tailored to make them versatile materials with applications in various technological fields. Careful examination of the powder X-ray diffractograms (XRDs) ensured the presence of pure spinel cubic crystal structure for all of the synthesized ferrite samples. Obtained high-resolution transmission electron microscopy images also validated the XRD results along with mean size, morphology, and regularity in both shape and size were examined thoroughly. With increasing the Sm percentage, the average size of ferrite nanoparticles reduced, which is also verified by the gradual increase in bandgap as obtained from Tauc plots. Additionally, it is found that the hopping of electrons under an applied alternating electric field was the main process of charge conduction for all the ferrite samples, and effects of grain boundaries dominated over grains in determining the dielectric responses. The incorporation of Sm3+ ions owning less magnetic moment compared to Fe3+ ions reduced both the coercive field and saturation magnetization gradually as noticed in M(H) loops. The aroused superparamagnetic phenomenon at room temperature due to Sm doping favored the magnetic controlled hyperthermia through induction heating. Bare Sm doped Cu–Ni ferrite samples showed excellent induction heating, obeying clinical safety limits. In addition, photon-mediated degradation of the ciprofloxacin (CIP) antibiotic was conducted using the as-prepared samples and it was found that 15% Sm doped Cu–Ni ferrite sample was sufficient to remove 95.8% of the CIP from the solution in 60 min. Moreover, doped ferrite samples also displayed excellent antioxidant and antidiabetic properties. Hence, Sm-doped Cu–Ni spinel nanoferrites are versatile materials with applications, especially in hyperthermia and photocatalysis. [ABSTRACT FROM AUTHOR]

Cobalt zinc chromium ferrites, which have been doped with chromium Co0.4Zn0.6-xCrxFe2O4 (x = 0.05, 0.10, 0.15, 0.20) (CZC) nanoferrites, are employed by the auto-combustion route. The magnetic and dielectric characteristics of Co–Zn nanoferrites were improved by Cr3+. Analysis using XRD, FTIR, and FESEM reveals the cubic spinel phase for CZC nanoferrites. SEM reveals a lot of clustering. The ferrite samples have cluster form with a spherical shape in the range 54.64–73.38 nm, as seen by the FESEM results. TEM studies show agglomeration. The Cr3+ concentration determines the magnetic properties of specimens. Ms declines from 62.38 emu/g to 42.59 emu/g by increasing Cr3+. For all samples, a frequency-dependent evaluation of the dielectric properties, including dielectric constant, dielectric loss, and ac conductivity, is performed. On the basis of Koop's theory, the Maxwell-Wagner polarization procedure, and the movement of electrons, the fluctuation of dielectric features at frequencies between 50 Hz and 108 Hz has been mentioned. The dielectric constant and dielectric loss tangent decreased with increasing frequency. The conduction of ferrite samples is influenced by the grain boundaries. Both recording media and high-frequency devices can benefit from using these nanoferrites. [ABSTRACT FROM AUTHOR]

Present work reports a systematic study on the evaluation of magnetic inhomogeneities in non-stoichiometric Mg 0·5 Ca 0·5 Fe 2 O 4 nanoferrite (MCNF) by conducting exhaustive dc-magnetization, ac-susceptibility and 57Fe Mössbauer spectroscopic measurements and exchange bias investigations using training protocol down to 6 K. Rietveld fitting to PXRD established the formation of anticipated spinel fcc phase of MCNF (non-stoichiometric) along with a minute impurity phase of calcite. Scherrer method and HRTEM micrographs illustrated broad size distribution of MCNF nanoparticles with an average nanocrystallite size of ∼15 nm. Combined 57Fe Mössbauer spectroscopic and dc-magnetization analysis establishes coexistence of ferrimagnetic (67 %) & superparamagnetic (33 %) states at 300 K with notable M s = 22 emu/g, M r = 4 emu/g & H c = 130 Oe and blocking of most of the nanoparticles of MCNF below 300 K. The coercivity followed the size-modified Kneller law for ferrimagnetic nanoparticles and the saturation magnetization abides the Bloch law. Moreover the frequency-dependent ac-susceptibility investigations revealed two magnetic transitions: (i) A transition at ∼ 330 K in the low frequency data attributed to the relaxation of blocked particles of bigger sizes under the superparamagnetic (SPM) regime and (ii) an irregularity at low temperatures is assigned to surface spin glass freezing. Surface spin glass freezing was further affirmed by the ageing experiments and dynamic scaling law. Furthermore, even the best fit to the dynamic scaling couldn't assert the existence of conventional spin glass phase due to slower spin-flip time of surface spins. A soft ferrimagnetic core of MCNF is enveloped with disordered surface spins, which manifest spin glass state. Concurrently, the findings of exchange bias at 30 K and training effect at 6 K affirmed that MCNF nanoparticles are presenting themselves as FM core- SG shell system. Our experimental findings suggested magnetic inhomogeneities comprised of superparamagnetism, ferrimagnetism and disordered surface spin glass state in the non-stoichiometric MCNF. [ABSTRACT FROM AUTHOR]

A bio approach (mediated by Agaricus bisporus) was attempted in the present study to synthesize ferrite nanoparticles MFe2O4 (M = Zn, Cu and Co]. The synthesized ferrites nanoparticles were characterized in terms of variations in the crystallinity, dimension and sizes using standard techniques (XRD, FTIR, SEM-EDAX, Zeta potential and DLS). VSM analysis showed noticeable differences in the magnetic saturation values: zinc ferrite (12.5 emu/g); cobalt ferrite (27.5 emu/g) and copper ferrite (21.5 emu/g). In- vitro cytotoxic effect of the synthesised ferrite nanoparticles resulted in effective inhibition of colon cell line growth (SW620). The ferrite nanoparticles were also evaluated for their drug-release behaviour using doxorubicin (DOX). The results indicated that the maximum DOX delivery was 98.74% using zinc ferrite, 97.34% using cobalt ferrite and 99.52% using copper ferrite within 6 h using 10 mg of nanoparticles. From the hyperthermia results, a SAR of 337 W/g was noted using 10 mg of copper ferrite nanoparticles at an applied frequency of 335 kHz and magnetic field strength of 235 A/m. [ABSTRACT FROM AUTHOR]

Nickel ferrite nanoparticles (NiFe2O4) have been proposed as a promising candidate for bacterial inactivation. In this study, cotton fabrics were modified by employing a simple adsorption technique to incorporate NiFe2O4. The surface morphology and quantitative analysis of the NiFe2O4-modified cotton fabrics were investigated using field emission scanning electron microscopy (FESEM). The shape and distribution of the NiFe2O4 within the cotton fabrics were examined through high-resolution transmission electron microscopy (HRTEM) analysis of cross-section fabric samples. The synthesized NiFe2O4 exhibited a nanospheric shape with a particle size diameter ranging from 40 to 60 nm. Nitrogen adsorption–desorption analysis confirmed the mesoporous nature of the modified cotton fabric samples. The antibacterial efficacy of the nickel ferrite nanoparticle-modified fabrics was evaluated against Proteus mirabilis, Staphylococcus aureus, Enterococcus aerogenes, Escherichia coli, Klebsiella pneumonia, and Pseudomonas fluorescens bacteria. Furthermore, the durability of the NiFe2O4 nanoparticles on the fabric surface was assessed by subjecting the modified fabrics to 50 cycles of laundering washing, which demonstrated that the nanoparticles did not leach out even after repeated washings. [ABSTRACT FROM AUTHOR]

This research investigated the antibacterial activities of AgFe2O4 and Fe3O4 ferrite nanoparticles compared to AgFe2O4/SiO2/Passiflora Caerulea and Fe3O4/SiO2/Passiflora Caerulea nanocomposites. To synthesize ferrite nanocomposites, Passiflora Caerulea plant extract was doped onto ferrite nanoparticles with the assistance of silica (SiO2). The degree of crystallinity, phase composition, microstructure, and the compositions of the samples were determined using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), and energy dispersive X-ray analysis (EDXA), respectively. Furthermore, the broth microdilution method was employed against Gram-positive and Gram-negative bacteria to assess the antimicrobial activity. The method was also applied to Gram-positive and Gram-negative bacteria to examine the antimicrobial activity. The results of the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of silver and iron nanocomposites indicated that these nanocomposites exhibited superior antibacterial activity compared to silver and iron ferrite nanoparticles. Thus, silver and iron ferrite nanocomposites could serve as a novel antibacterial agent against infectious bacteria. [ABSTRACT FROM AUTHOR]

In this work, cadmium doped cobalt nickel ferrites were fabricated via co-precipitation method by using high purity chlorides as precursors and ammonia as precipitate. XRD measurements of synthesized Co0.6Ni0.4-xCdxFe2O4 ferrite samples revealed that the formation of mono phase cubic spinel structure ferrite nanoparticles. The volume of unit cell, crystallite size, lattice constant, bond length, hopping length, ionic radii and microstrain were directly affected by the inclusion of Cd2+ content in Co-Ni ferrite. The crystallite size (Dxrd) of prepared ferrite samples was obtained in between 14.52 and 16.92 nm. FTIR spectra showed two main absorption bands in the frequency range of 400–600 cm−1 arising due to stretching vibrations of tetrahedral (A) and octahedral (B) sites respectively. SEM analysis showed agglomerated morphology of ferrite nanoparticles with grain size decreased from 0.85 to 0.21 μm. Raman spectroscopy confirmed that, on addition of Cd2+content, Raman band was shifted towards higher wave number side. The crystallite development in Cd doped Co-Ni ferrites was explored by X-ray peak broadening methods such as Scherer’s formula, Size-Strain plot and Williamson hall methods. XRD analysis confirmed, the crystallite size and microstrain of Co0.6Ni0.4-xCdxFe2O4 ferrites were obtained from various methods, are highly inter correlated. Saturation magnetization (Ms) was decreased from 29.92 to 23.40 emu/gm with increase of Cd doping. The coercivity was reduced from 1113 to 708 Oe with Cd concentration. This is due to the magnetic anisotropy constant of Ni2+ ion is higher than that of the Cd2+ ion.

Abstract This work is concerned with fabricating ferrite nanoparticles of nickel–zinc with the chemical formula: Ni0.55Zn0.45Fe2−x Ce x O4, 0 ≤ x ≤ 0.011 by co-deposition technique and modifying their electrical, microscopic, spectroscopic, optical, electrical and dielectric properties as advanced engineering materials through doping with the cerium (Ce) element. XRD patterns displayed that the samples have a monophasic Cerium–Nickel–zinc (CNZ) spinel structure without other impurities for cerium concentration (x) ≤ 0.066. Both values of crystallite size and lattice parameters decrease from 33.643 to 23.137 nm and from 8.385 to 8.353 nm, respectively, with the increasing Ce ions substitution content from 0 to 0.066. SEM images indicate that grains of the fabricated compounds are smaller, more perfect, more homogeneous, and less agglomeration than those of the un-doped Ni–Zn nano-ferrites. The maximum intensity of first-order Raman spectral peaks (E g, F2g(2), A1g(2), and A1g(1)) of CNZ ferrite nanoparticles are observed at about (330, 475, 650, 695) cm−1, respectively, that confirms the CNZ samples have the cubic spinel structure. The direct and indirect optical energy bandgaps of CNZ samples have a wide spectrum of values from semiconductors to insulators according to cerium concentration. The results showed that the values of dielectric constant, dielectric loss factor, and Ac conductivity and the conductivity transition temperature are sensitive to cerium ions content. AC conductivity exhibited by the CNZ samples has the semiconductor materials behavior, where the AC conductivity increases due to temperature or doping concentration. The results indicate that Ni0.55Zn0.45Fe1.944Ce0.066O4 ferrite nanoparticles may be selected for optoelectronic devices, high-frequency circuits, and energy storage applications.

The primary goal of this work was to develop a cost-effective, non-toxic, eco-friendly, and simple approach for the green synthesis of CoFe2O4 nanoparticles (NPs) using Aloe vera leaf extract by the sol–gel auto-combustion method. In order to figure out their structural, morphological, and magnetic properties, the synthesized NPs were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscope (TEM), dynamic light scattering (DLS), zeta potential, and vibrating-sample magnetometer (VSM). XRD analysis showed that particles had a single-phase spinel crystalline structure with an average crystalline size of 33.5 nm. Under VSM studies, the produced NPs exhibit a soft ferromagnetic property. SEM revealed that the as-prepared NPs were agglomerated due to their magnetic behavior. To the best of our knowledge, the anticandidal, antibiofilm, antibacterial, and anticancer activities of CoFe2O4 NPs toward drug-resistant gram-positive and gram-negative bacteria, as well as fungal strains, have been comprehensively investigated for the first time. The synthesized NPs had a minimal inhibitory concentration of 0.25–0.75 mg/ml against the tested pathogens. CoFe2O4 NPs inhibited the biofilm formation by 37.3–61.8% in selected strains at concentrations of 0.125–0.5 mg/ml. It was observed that the NPs not only suppress biofilm formation but also eradicate established mature biofilms by 50.9–64.49% that was further supported by SEM. SEM analysis shows that NPs significantly inhibit the colonization and aggregation of tested biofilm strains. Light microscopic analysis revealed that NPs completely inhibit the development of hyphae and filaments in Candida albicans, which significantly attenuates their pathogenicity. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays and 4′,6-diamidino-2-phenylindole (DAPI) staining demonstrate that NPs significantly inhibit the proliferation of HCT-116 and HeLa cells. Furthermore, the SEM images of treated cells showed wrinkled and damaged cell walls, indicating the disruption and disorganization of the membrane. This study showed that the synthesized NPs were effective in inhibiting the growth of drug-resistant bacteria, candida, and their preformed biofilms as well. Thus, these NPs with broad-spectrum applications could be exploited in medical settings to diminish biofilm-based infections caused by these pathogenic strains.

This work is concerned with fabricating ferrite nanoparticles of nickel–zinc with the chemical formula: Ni0.55Zn0.45Fe2−xCexO4, 0 ≤ x ≤ 0.011 by co-deposition technique and modifying their electrical, microscopic, spectroscopic, optical, electrical and dielectric properties as advanced engineering materials through doping with the cerium (Ce) element. XRD patterns displayed that the samples have a monophasic Cerium–Nickel–zinc (CNZ) spinel structure without other impurities for cerium concentration (x) ≤ 0.066. Both values of crystallite size and lattice parameters decrease from 33.643 to 23.137 nm and from 8.385 to 8.353 nm, respectively, with the increasing Ce ions substitution content from 0 to 0.066. SEM images indicate that grains of the fabricated compounds are smaller, more perfect, more homogeneous, and less agglomeration than those of the un-doped Ni–Zn nano-ferrites. The maximum intensity of first-order Raman spectral peaks (Eg, F2g(2), A1g(2), and A1g(1)) of CNZ ferrite nanoparticles are observed at about (330, 475, 650, 695) cm−1, respectively, that confirms the CNZ samples have the cubic spinel structure. The direct and indirect optical energy bandgaps of CNZ samples have a wide spectrum of values from semiconductors to insulators according to cerium concentration. The results showed that the values of dielectric constant, dielectric loss factor, and Ac conductivity and the conductivity transition temperature are sensitive to cerium ions content. AC conductivity exhibited by the CNZ samples has the semiconductor materials behavior, where the AC conductivity increases due to temperature or doping concentration. The results indicate that Ni0.55Zn0.45Fe1.944Ce0.066O4 ferrite nanoparticles may be selected for optoelectronic devices, high-frequency circuits, and energy storage applications. [ABSTRACT FROM AUTHOR]

Abstract This study investigates the behavior of the mono and hybrid nanofluid flows in an absorbent dilating/squeezing channel influenced by a magnetic field. The mono nanofluid is molded by inserting iron oxide (Fe3O4) nanoparticles into the blood (base fluid) and the targeted hybrid magnetic nanofluid is formed when the Cobalt iron oxide (CoFe2O4) nanoparticles are added into Fe3O4/blood nanofluid mixture. For a permeable channel, the slip boundary along with the thermal jump condition is imposed. The process for heat transfer is examined considering the Cattaneo-Christov heat flux. Throughout the analysis, platelet-shaped nanoparticles are used. The Tiwari and Das (single phase) nanoliquid flow model is adopted here. The ordinary differential equations (ODEs) are accomplished via similarity transformations and are numerically assessed using the bvp4c software. Moreover, the consequences of the resulting pertinent parameters on the streamlines, temperature, and velocity distributions are scrutinized using graphical representations. It is observed that the surface drag on the wall is weaker for the dilating/injection case as compared to the squeezing/suction scenario. Streamlines show how a suitable magnetic field may be used to regulate medicine distribution in the blood flow. An innovative mass-based model comprising mono and hybrid nanofluid flow models is discussed. A comparison of heat transfer between both is undertaken. The results indicate that increasing the magnetic parameter leads to an enhancement in heat transfer rate when the upper and lower walls are dilated with wall injection ( α = 0.2 , Re = 0.5 ) . Conversely, if the upper and lower walls are squeezed with wall suction ( α = − 0.2 , Re = − 0.5 ) , the heat transfer rate decreases. The novelty lies in the consideration of both types of models and making a comparison of these. [ABSTRACT FROM AUTHOR]

Magnetoelectric (ME) polymer nanocomposites find a wide range of applications as ME sensors, energy storage devices, magneto‐mechano‐electric nanogenerators, tissue engineering scaffolds, and so forth. Functionalizing ferrite fillers is an effective strategy to improve the ferrite‐polymer interaction and, thereby, the functional properties. In the present work, we developed ternary nanocomposite fibers of polyvinylidene fluoride loaded with hydrated salt and alginate functionalized ferrite nanoparticles. Nanocomposites with functionalized ferrite fillers were found to have better dielectric and ME properties. The highest values of dielectric constant (14.7) and ME coupling coefficient (18.2 mV cm−1 Oe−1) were obtained for ternary nanocomposite fiber with functionalized nickel ferrite nanoparticles. The present study opens new avenues for developing flexible ME nanocomposites for realizing flexible ME nanocomposites with the required properties for developing next‐generation devices for diverse applications. [ABSTRACT FROM AUTHOR]

Magnesium ferrite (MgFe2O4) and polyethylene glycol (PEG) are materials known for their versatility in various applications. This study presents a comprehensive comparative analysis of the electrical conductivity and dielectric relaxation of nanostructured MgFe2O4 and its composites with PEG. Through experimentation, it was observed that incorporating PEG into MgFe2O4 did not lead to a high relative observed decrease or increase in electrical conductivity at room temperature. The study revealed that the composites maintained stable electrical behavior at room temperature, with a dielectric constant value of around 9 and a loss tangent value of around 0.1 at high frequency (around 7 MHz). The electron-hole hopping mechanism was identified as the underlying cause for the strong dielectric dispersion with frequency. The low dielectric loss and conductivity of the MgFe2O4 and PEG/ferrite composites make them promising candidates for high-frequency switching applications and microelectronic devices, particularly in scenarios where negligible eddy currents are essential. Additionally, complex impedance data analysis demonstrated that the capacitive and resistive properties of the composites are primarily attributed to grain boundary processes. This study provides a comprehensive analysis of the electrical and dielectric properties of MgFe2O4 and PEG composites and highlights their potential for many applications in materials science, particularly in electrical and electronic devices.

Novel biocompatible and efficient photothermal (PT) therapeutic materials for cancer treatment have recently garnered significant attention, owing to their effective ablation of cancer cells, minimal invasiveness, quick recovery, and minimal damage to healthy cells. In this study, we designed and developed calcium ion-doped magnesium ferrite nanoparticles (Ca2+-doped MgFe2O4 NPs) as novel and effective PT therapeutic materials for cancer treatment, owing to their good biocompatibility, biosafety, high near-infrared (NIR) absorption, easy localization, short treatment period, remote controllability, high efficiency, and high specificity. The studied Ca2+-doped MgFe2O4 NPs exhibited a uniform spherical morphology with particle sizes of 14.24 ± 1.32 nm and a strong PT conversion efficiency (30.12%), making them promising for cancer photothermal therapy (PTT). In vitro experiments showed that Ca2+-doped MgFe2O4 NPs had no significant cytotoxic effects on non-laser-irradiated MDA-MB-231 cells, confirming that Ca2+-doped MgFe2O4 NPs exhibited high biocompatibility. More interestingly, Ca2+-doped MgFe2O4 NPs exhibited superior cytotoxicity to laser-irradiated MDA-MB-231 cells, inducing significant cell death. Our study proposes novel, safe, high-efficiency, and biocompatible PT therapeutics for treating cancers, opening new vistas for the future development of cancer PTT. [ABSTRACT FROM AUTHOR]

In the present work, CuXMn1–XFe2O4 (X = 0, 0.05, 0.1, 0.15, and 0.2) ferrite nanoparticles were synthesized using reverse co-precipitation and the effects of Cu2+ doping with different percentages on the structural and magnetic properties of manganese ferrite nanoparticles have been investigated. The microstructural evolutions, the magnetic properties, the bandgap, and the dielectric properties of Cu-doped nanoparticles were evaluated. These studies were carried out using X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), energy dispersive X-ray analysis (EDX), vibrating sample magnetometer (VSM), and diffuse reflectance spectroscopy (DRS). The morphology of the synthesized nanoparticles was observed to be spherical and almost uniform. The bandgap of the samples decreased with increasing copper content due to the integration of the sub-bands with the conductive band as well as the additional energy levels of the sub-bands created by the high surface area and interfacial defects in the agglomerated nanoparticles. Moreover, both dielectric constant and dielectric loss increase at low frequencies and decrease at high frequencies. [ABSTRACT FROM AUTHOR]

Optical characteristics of Cobalt ferrites nanoparticles (CoFe2O4) deposited on different substrates are presented and discussed in this paper. These CoFe2O4 nanoparticles, were synthesized using one pot solvo-thermal route and using acetylacatonates of iron and cobalt as precursors. These nanoparticles were deposited by spin coating on Silicon substrate (CoFe2O4/Si) and on Porous Silicon (CoFe2O4/PSi) which is prepared via electrochemical etching using p-type Si (100) wafers. Besides; morphological, structural, optical and photoluminescence properties of the nanocomposites will be investigated. Firstly, a scanning electron microscope (SEM) will be used to study the morphology. The Structural Characterization will be done by (XRD) X-Ray diffraction (Cu-Kα radiation). The optical and the photoluminescence properties of the different composites will be also studied using photoluminescence (PL), and Reflectance by a UV–VIS spectrophotometer. As to sum up the results of our research, the morphology of the deposited nanoparticles relies on the used substrate. The enhancement of the optical properties will be investigated by UV–vis reflectance, Fast Fourier Transform (FFT) of the reflectance spectra and Photoluminescence (PL) analyses. Band gap values were determined using the Tauc-plot method. The energies of the indirect optical transition were determined for cobalt ferrites deposited. The (CoFe2O4/PSi) composite exhibits a large emission in the visible domain. This research opens up new opportunities for building transparent and flexible light sources, photodetectors, and wearable sensors by providing a feasible way for investigating photoluminescence in ferroelectric thin-film systems. [ABSTRACT FROM AUTHOR]

The influence of microwave (MW) plasma on magnetization and morphology of sol-gel synthesized MnFe2O4 ferrite nanoparticles is investigated in this study. Manganese (II) nitrate hexahydrate, ferric (III) nitrate nanohydrate and citric acid were used to synthesize ferrite nanoparticles via a facile sol-gel route. These ferrite nanostructures were heat-treated at 700ºC and then given MW plasma treatment for 10 min. The pristine MnFe2O4 and plasma treated MnFe2O4 showed almost similar structural formation with a slight increase in crystallinity on plasma treatment. However, XRD peak intensity slightly increased after plasma treatment, reflecting better crystallinity of the nanostructures. The size of the particle increased from 35 nm to 39 nm on plasma treatment. It was challenging to deduce the surface morphology of the nanoparticles since both samples were composed of a mixture of big and small clusters. Clusters that had been treated with plasma were larger in size than pristine ones. The band gap energy of the pristine MnFe2O4 sample was about 5.92 eV, which increased to 6.01 eV after treatment with MW plasma. The saturation magnetization of MnFe2O4 sample was noted about 0.78 emu/g before plasma treatment and 0.68 emu/g after MW plasma treatment.

In the last few decades, there has been enormous growth in ferrite nanoparticles. Magnetic, optical, and electrical properties of ferrites gain consideration due to their use in various applications such as rechargeable lithium batteries, medical diagnostics, solar energy devices, and so forth. A vast increase in interest in ferrite nanoparticles has led them to be used as catalysts in various applications as they possess a large surface area‐to‐volume ratio. Furthermore, iron‐based magnetic characteristics make it simple to retrieve catalysts by using an external magnet. Iron's catalytic potential, however, is far less than copper's. Therefore, the catalytic scope is substantially increased by substituting copper within the crystal lattice. Recently copper ferrite nanoparticles have caught the interest of numerous researchers due to low‐cost magnetic material, stability under diverse conditions, and ease at which catalyst can be retrieved using an external magnetic field and utilized repeatedly. This review of data from year 2010 through 2022 emphasizes the synthesis method, structure, application in dyes degradation, catalytic potential in the number of coupling reactions, recyclability, and reusability of the magnetic catalyst. [ABSTRACT FROM AUTHOR]

Methylene blue (MB) dye is a common colorant used in numerous industries, particularly the textile industry. When methylene blue is discharged into water bodies without being properly treated, it may seriously damage aquatic and human life. As a result, a variety of methods have been established to remove dyes from aqueous systems. Thanks to their distinguishing features e.g., rapid responsiveness, cost-effectiveness, potential selectivity, portability, and simplicity, the electrochemical methods provided promising techniques. Considering these aspects, a novel quartz crystal microbalance nanosensors based on green synthesized magnesium ferrite nanoparticles (QCM-Based MgFe2O4 NPs) and magnesium ferrite nanoparticles coated alginate hydrogel nanocomposite (QCM-Based MgFe2O4@CaAlg NCs) were designed for real-time detection of high concentrations of MB dye in the aqueous streams at different temperatures. The characterization results of MgFe2O4 NPs and MgFe2O4@CaAlg NCs showed that the MgFe2O4 NPs have synthesized in good crystallinity, spherical shape, and successfully coated by the alginate hydrogel. The performance of the designed QCM-Based MgFe2O4 NPs and MgFe2O4@CaAlg NCs nanosensors were examined by the QCM technique, where the developed nanosensors showed great potential for dealing with continuous feed, very small volumes, high concentrations of MB, and providing an instantaneous response. In addition, the alginate coating offered more significant attributes to MgFe2O4 NPs and enhanced the sensor work toward MB monitoring. The sensitivity of designed nanosensors was evaluated at different MB concentrations (100 mg/L, 400 mg/L, and 800 mg/L), and temperatures (25 °C, 35 °C, and 45 °C). Where a real-time detection of 400 mg/L MB was achieved using the developed sensing platforms at different temperatures within an effective time of about 5 min. The results revealed that increasing the temperature from 25 °C to 45 °C has improved the detection of MB using the MgFe2O4@CaAlg NCs nanosensor and the MgFe2O4@CaAlg NCs nanosensor exhibited high sensitivity for different MB concentrations with more efficiency than the MgFe2O4 NPs nanosensor. [ABSTRACT FROM AUTHOR]

This paper reports the impacts of cerium (Ce) substitution on morphological, magnetic and structural characteristics of Mn0.5Zn0.5CexFe2-xO4 (x = 0.0, 0.3 and 0.5) ferrites nanoparticles (NPs) prepared via sol gel combustion method. The crystalline structure, magnetic and morphological features were examined by powder X-ray diffraction, vibrating sample magnetometer and scanning electron microscope analyser individually. Magnetic hysteresis (M−H) loops of samples were determined to examine the magnetic properties of synthesized samples. Magnetic measurement shows that samples exhibit ferromagnetic behaviour at room temperature (RT). The magnetic properties are described in terms of cation substitution and grain size effect. The various concentration of synthesized photocatalyst such as Mn0.5Zn0.5Fe2O4, Mn0.5Zn0.5Ce0.3Fe1.7O4 and Mn0.5Zn0.5Ce0.5Fe1.5O4 NPs were analysed under visible light irradiation by the degradation of an aqueous solution of Congo red and Reactive Orange 16 dyes and the sample Mn0.5Zn0.5Ce0.3Fe1.7O4 NPs showed higher degradation percentage 97.25% and 98.42% respectively, than other compositions at 120 min with enhanced visible light absorption range. These performances expose that these nanomaterials are appropriate for high frequency applications.

[Display omitted] • Investigated the effect of Al3+-Gd3+ co-doping on nanoscale CoFe 2 O 4. • Studied structural, morphological, surface, magnetic, electrical, and dielectric properties. • Significant influence observed across all properties with Al3+-Gd3+ co-doping. • Potential application of co-doped nanoparticles in electronic devices highlighted. The magnetic spinel ferrites nanomaterials simultaneously doped with multivalent cations have gained a lot of interest from many researchers during the last decade. Also, the doping of trivalent rare-earth ions in spinel ferrites is promising for many technological applications. Considering these facts, in this work we investigated the trivalent Al3+-Gd3+ ions co-doped cobalt ferrite nanoparticles with nominal composition as CoFe 2-2x Al x Gd x O 4 (x = 0.00, 0.03, 0.05, 0.07, 0.10). The sol–gel auto ignition route assisted by citric acid as a chelating agent was utilized to synthesize the series of nanoparticles. The Rietveld refined X-ray diffraction (XRD) patterns were analyzed to ensure the single-phase formation of nanoparticles with spinel cubic structure. The spherical-shaped grain morphology of the nanoparticles was indicated by scanning electron microscopy (SEM) images. The elemental analysis obtained by energy dispersive X-ray analysis (EDAX) revealed stoichiometric formation of the samples along with high purity. The two prominent frequency modes analogous to the spinel ferrite structure were noted in the infrared spectra assuring the successful formation of all the samples. The soft magnetic behaviour with a lower coercivity of the prepared nanoparticles was confirmed by the vibrating sample magnetometer (VSM) technique. The DC electrical resistivity plots indicated that resistivity decreases with an increase in Al3+-Gd3+ co-doping. The dielectric studies of all the samples showed increasing behaviour with an increase in Al3+-Gd3+ co-doping. All the results suggest that the Al3+-Gd3+ co-doped cobalt ferrite nanoparticles can be useful for real-world applications, specifically in nanoelectronics devices. [ABSTRACT FROM AUTHOR]

In this study, three types of ferrites nanoparticles including CoFe2O4, NiFe2O4, and ZnFe2O4 were synthesized by microwave-assisted hydrothermal method. The X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FESEM) were employed to analyze synthesized nanoparticles and fabricated membranes. The morphology of membrane surface was investigated by surface images. The ability of ferrite nanoparticles was evaluated to the separation of sodium salt and heavy metals such as Cr2+, Pb2+, and Cu2+ from aqueous solutions. The modified membrane showed the enhancement of membrane surface hydrophilicity, porosity, and mean pore size. The results revealed a significant increase in pure water flux: 152.27, 178, and 172.68 L·m−2·h−1 for PES/0.001 wt% of CoFe2O4, PES/0.001 wt% NiFe2O4, and PES/0.001 wt% ZnFe2O4 NPs, respectively. Moreover, Na2SO4 rejection was reached 78% at 0.1 wt% of CoFe2O4 NPs. The highest Cr (II) rejection obtained 72% for PES/0.001 wt% of NiFe2O4 NPs while it was 46% for the neat PES membrane. The Pb(II) rejection reached above 75% at 0.1 wt% of CoFe2O4 NPs. The Cu(II) rejection was obtained 75% at 0.1 wt% of CoFe2O4 NPs. The ferrite NPs revealed the high potential of heavy metal removal in the filtration membranes.

Erbium-doped zinc ferrite nanoparticles (ZnFe1.9Er0.1O4) were prepared by the sol–gel auto-combustion method. In order to study the impact of calcination temperature, the prepared powder was divided into four parts and calcinated at 700, 900, 1100 and 1300°C. XRD confirmed the formation of a spinel structure with a single phase and Fd3m space group. Crystallite size increased from 19.45 to 30.22 nm with the increase in calcination temperature. SEM images showed agglomerated flakes having voids and pores on the surface. The average grain size increased from 157.76 to 237 nm with the increase in calcination temperature. FTIR showed two fundamental absorption bands related to octahedral and tetrahedral sites along with other three absorption bands in the frequency range 400–4000 cm−1. The optical energy bandgap was increased from 3.8166 to 4.2779 eV with the increase of calcination temperature. Hence, it is concluded that the optical energy bandgap can be tuned with the calcination temperature. [ABSTRACT FROM AUTHOR]

The nano-sized magnesium doped zinc ferrite (MgxZn1-xFe2O4 for x = 0.2 and 0.6) has been synthesised for biomedical application through two different routes (sol–gel and hydrothermal). The x-ray diffraction pattern showed the single phase of ferrite. The crystallite sizes and lattice parameters of Mg-Zn ferrite were obtained by three different methods viz. Scherrer formula (X'pert high score), Maud analysis (Rietveld refinement software), and Williamson Hall Plot. The field emission scanning electron microscopy revealed the near-spherical and dumbbell-shaped morphology of Mg-Zn ferrite. The vibrating sample magnetometer showed the increasing magnetic properties on increasing Mg doping. The elemental dispersive spectroscopy analysis revealed the presence of desired elements. The antimicrobial assay against E. coli (gram-negative) and S. aureus (gram-positive) bacteria showed a clear zone of inhibition. The Mg-Zn ferrite showed good magnetic and antimicrobial properties synthesised via the sol–gel route, which can be further used for possible drug delivery applications. [ABSTRACT FROM AUTHOR]

Nanophotocatalysts have been extensively used in recent years for the degradation of organic pollutants, removal of heavy metals, hydrogen production, treatment of air and water, etc. The high catalytic efficiency and recycling of the used nanophotocatalysts are the foremost concerns of this research field. The latter issue can be addressed by fixing the photocatalyst onto a substrate of flexible surface without hindering its catalytic activity. In this study, MgFe2O4/ZnO nanophotocatalyst was loaded over perlite substrate via co-precipitation method for easy recycling. The magnetic ferrite in the nanocomposite ensured better efficiency over multiple dye degradation cycles. Different characterization techniques, including XRD, SEM, EDX, PL, UV–Vis–DRS, Raman, and FTIR, were used to investigate the opto-physical, magnetic, electrical, and photocatalytic response of the synthesized MgFe2O4/ZnO/perlite composites. The ternary composite provided enhanced optical harvesting ability and accelerated the formation and transportation of photo-generated electron–hole pairs. MgFe2O4/ZnO/perlite catalyst presented better photocatalytic efficiency in methylene blue degradation than MgFe2O4 and ZnO. The dye degradation efficiency of MgFe2O4/ZnO/perlite catalyst was 5 and 4 times higher than MgFe2O4 and ZnO, respectively. The present research paved a new pathway toward the design and preparation of novel photocatalysts using ferrite materials. [ABSTRACT FROM AUTHOR]

The main idea of this paper is to incorporate and solidify magnetic nanoparticles of CoFe2O4 with a size less than 20 nm in a synthesized porous alumina membrane. In such a configuration, all the magnetic particles are oriented according to an external magnetic field and stay in this orientation even without a magnetic field after the solidification of the matrix. The procedure consists of three preliminary steps. First, we mixed the well-dispersed CoFe2O4 nanoparticles in a hexane solvent, to have a state transition from the liquid (CoFe2O4 nanoparticles surrounded by organic layer and dispersed in hexane) to the solid one of CoFe2O4. Second, we incorporate CoFe2O4 nanoparticles into the alumina membrane pores. Finally, a step of a heat treatment compatible with the magnetic nanoparticles is necessary to evaporate all the organic compounds. The insertion of nanoparticles has been done with the help of an external magnetic field. This work presents a new technique to synthesis a solid regular array of cobalt ferrite nanorods. After the removal of AAO membrane, cobalt ferrite nanorods can be used as a host for another material to prepare a nanocomposite material like extrinsic multiferroic. [ABSTRACT FROM AUTHOR]

Spinel ferrites are widely investigated for their widespread applications in high-frequency and energy storage devices. This work focuses on enhancing the magnetic and dielectric properties of Ni0.25Cu0.25Zn0.50 ferrite series through non-thermal microwave plasma exposure under low-pressure conditions. A series of Ni0.25Cu0.25Zn0.50 ferrites was produced using a facile sol–gel auto-ignition approach. The post-synthesis plasma treatment was given in a low-pressure chamber by sustaining oxygen plasma with a microwave source. The structural formation of control and plasma-modified ferrites was investigated through X-ray diffraction analysis, which confirmed the formation of the fcc cubical structure of all samples. The plasma treatment did not affect crystallize size but significantly altered the surface porosity. The surface porosity increased after plasma treatment and average crystallite size was measured as about ~49.13 nm. Morphological studies confirmed changes in surface morphology and reduction in particle size on plasma exposure. The saturation magnetization of plasma-exposed ferrites was roughly 65% higher than the control. The saturation magnetization, remnant magnetization, and coercivity of plasma-exposed ferrites were calculated as 74.46 emu/g, 26.35 emu/g, and 1040 Oe, respectively. Dielectric characteristics revealed a better response of plasma-exposed ferrites to electromagnetic waves than control. These findings suggest that the plasma-exposed ferrites are good candidates for constructing high-frequency devices. [ABSTRACT FROM AUTHOR]

The influence of microwave (MW) plasma on magnetization and morphology of sol-gel synthesized MnFe2O4 ferrite nanoparticles is investigated in this study. Manganese (II) nitrate hexahydrate, ferric (III) nitrate nanohydrate and citric acid were used to synthesize ferrite nanoparticles via a facile sol-gel route. These ferrite nanostructures were heat-treated at 700°C and then given MW plasma treatment for 10 min. The pristine MnFe2O4 and plasma treated MnFe2O4 showed almost similar structural formation with a slight increase in crystallinity on plasma treatment. However, XRD peak intensity slightly increased after plasma treatment, reflecting better crystallinity of the nanostructures. The size of the particle increased from 35 nm to 39 nm on plasma treatment. It was challenging to deduce the surface morphology of the nanoparticles since both samples were composed of a mixture of big and small clusters. Clusters that had been treated with plasma were larger in size than pristine ones. The band gap energy of the pristine MnFe2O4 sample was about 5.92 eV, which increased to 6.01 eV after treatment with MW plasma. The saturation magnetization of MnFe2O4 sample was noted about 0.78 emu/g before plasma treatment and 0.68 emu/g after MW plasma treatment. [ABSTRACT FROM AUTHOR]

Removal of heavy metals (Cd and Cr) from industrial wastewater by adsorption onto a series of Ca substituted nickel zinc nanoferrites (Ca x Ni 0.4 Zn 0.6-x Fe 2 O 4 (x = 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6)) (CNZNFs) was studied in detail. The effect of calcium doping and contact time over adsorption of cadmium and chromium ions was investigated and maximum uptake of Cd (98.25%) and Cr (51%) ions were marked by prepared nanoadsorbents. Structural studies confirmed the formation of spinel structured nanoparticles with crystallite size ranging from 24 to 38 nm while porosity was observed to vary from 52% to 58% with calcium concentration. Pseudo second order (PSO) kinetic model for adsorption of both heavy metals (cadmium and chromium) was observed to be better fitted with adsorption data. Maximum adsorption efficiencies for Cd (128.20 mg/g) and Cr (23.54 mg/g) were found by the data fit of Langmuir isotherm model. Additionally, the adsorption data was found to obey Langmuir isotherm model for both heavy metals due to higher values of correlation coefficients (R2 = 0.94131 for cadmium and 0.91091 for chromium) than Freundlich isotherm model (R2 = 0.5865 for cadmium and 0.4599 for chromium). • Formulae used for calculations of structural parameters from XRD plots • Linear and non linear equations for adsorption kinetics and isotherm models • Parameters calculated by pseudo first order and pseudo second order adsorption kinetics • Results of various plots for adsorption of cadmium and chromium ions onto Ca x Ni 0.4 Zn 0.6-x Fe 2 O 4 (x = 0.1) magnetic nanoparticles [ABSTRACT FROM AUTHOR]

In this paper, firstly, the required ferrite nanopowders (cobalt, nickel, and copper ferrites) were synthesized by the microwave method. Nickel ferrite shows super-paramagnetic behavior, while cobalt and copper ferrite illustrate ferromagnetic properties. Then, surface nanocomposites were made using friction stir processing (FSP) with AA7075 aluminum alloy sheets (as base metal) and fabricated ferrite nanopowders. In the next step, the parts were prepared by wire-cut for various tests. The results showed that the nanopowders were well-distributed in the aluminum alloy matrix and fine-grained structures were created. The outcomes of micro-hardness tests illustrated that the hardness of the samples significantly improved after FSP. Also, the results of tensile tests confirmed that the tensile properties of surface nanocomposite AA7075/CoFe2O4 were better than other samples. [ABSTRACT FROM AUTHOR]

The nano-crystalline mixed ferrites with the generic formula MnxMg1 − xFe2O4 (x = 0.0–1.0, step: 0.2) were prepared by the citrate-gel auto-combustion technique. Motivated by anomalous magnetic behaviour of coarse-grained MnFe2O4, the main aim was to study the influence of Mn2+ substitution in MgFe2O4 on magnetic structure at nano-regime. The compositional stoichiometry of the final ferrite products was ascertained by EDAX mapping and particle size for each sample was determined by powder X-ray diffraction, TEM, small-angle X-ray and neutron scattering techniques. The lattice constant increases with Mn-content due to larger cation (Mn2+) substitution. The distribution of cations in the tetrahedral (A) and octahedral (B) interstitial sites of the spinel lattice is determined by X-ray diffraction and Mossbauer spectral intensity analysis. The Mossbauer spectra at room temperature exhibit two sextets due to A- and B-sites for compositions x = 0.0, 0.2 and 1.0 while spectra showed central paramagnetic doublet superimposed on magnetic sextets for the samples with x = 0.4, 0.6 and 0.8, ascribed to the presence of superparamagnetic clusters. Thermal variation of AC susceptibility showed hump near the Curie temperature due to the presence of superparamagnetic clusters as corroborated by Mossbauer signature. The observed saturation magnetic moment (at temperature 5 K and applied field 9 T) is found lower compared to Neel's moment for the compositions with x > 0.2 which is explained on the basis of the exchange disorder of Fe3+ ions in the B-sites in Mn-containing ferrites. [ABSTRACT FROM AUTHOR]

Novel biocompatible and efficient photothermal (PT) therapeutic materials for cancer treatment have recently garnered significant attention, owing to their effective ablation of cancer cells, minimal invasiveness, quick recovery, and minimal damage to healthy cells. In this study, we designed and developed calcium ion-doped magnesium ferrite nanoparticles (Ca2+-doped MgFe2O4 NPs) as novel and effective PT therapeutic materials for cancer treatment, owing to their good biocompatibility, biosafety, high near-infrared (NIR) absorption, easy localization, short treatment period, remote controllability, high efficiency, and high specificity. The studied Ca2+-doped MgFe2O4 NPs exhibited a uniform spherical morphology with particle sizes of 14.24 ± 1.32 nm and a strong PT conversion efficiency (30.12%), making them promising for cancer photothermal therapy (PTT). In vitro experiments showed that Ca2+-doped MgFe2O4 NPs had no significant cytotoxic effects on non-laser-irradiated MDA-MB-231 cells, confirming that Ca2+-doped MgFe2O4 NPs exhibited high biocompatibility. More interestingly, Ca2+-doped MgFe2O4 NPs exhibited superior cytotoxicity to laser-irradiated MDA-MB-231 cells, inducing significant cell death. Our study proposes novel, safe, high-efficiency, and biocompatible PT therapeutics for treating cancers, opening new vistas for the future development of cancer PTT.

In this paper, the impact of cerium (Ce) additives on the structural, electrical and radiation attenuation characteristics of cerium zinc (Zn)- manganese (Mn)-based spinel nanoferrite, named ZMCeF -nanoferrite was investigated. Our investigation involved a thorough examination of the morphology and distribution of the ZMCeF -nanoferrite utilizing HR-TEM analysis, which revealed showcasing the distinctive spherical morphology of the nanoparticles along with observations of their aggregation tendencies. These findings are ascribed to the heightened magnetic interactions between the ZMCeF -ferrite nanoparticles. The ZMCeF5 nanoferrite demonstrates an optimal dielectric constant value compared to the free Ce ferrite composition, exhibiting an enhancement ratio of 109 %. Additionally, it showcases optimal conductivity, with an upgrading ratio of 780 %, and minimal loss, with an enhancing ratio of 3.5 %. Moreover, the elastic moduli of the ZMCeF5 sample exhibited a marked increase as the Ce content increased. Upon examining the mass attenuation coefficient (MAC) of ZMCeF-nanoferrite across three energy regions, we note a trend of increased MAC values corresponding to higher Ce additions. In contrast, the half-value layer (HVL) values decrease as Ce additions increase. Comparing the HVL values of the current ZMCeF -nanoferrite with those of selected radiation shielding material, we find that HVL of the ZMCeF -nanoferrite exhibits smaller values. These findings present promising prospects for optimizing spinel nanomaterials for use in radiation shielding applications. • HR-TEM results evidenced the spherical shapes and the aggregation of nanoparticles. • The ZMCeF5 nanoferrite has the optimal dielectric constant value compared to the other samples. • The half value layer (HVL) values decreased with increasing Ce additions. • The Half-Value Layer (HVL) of the ZMCeF-nanoferrite are smaller than that of other chosen radiation shielding materials. [ABSTRACT FROM AUTHOR]