Superparamagnetic Behavior Research Articles

Shape‐Control in Microwave‐Assisted Synthesis: A Fast Route to Size‐Tunable Iron Oxide Nanocubes with Benchmark Magnetic Heat Losses

AbstractIron oxide nanocubes (IONCs) are among the most promising materials in magnetic hyperthermia (MHT) for tumor therapy as they can efficiently convert magnetic energy into heat under alternating magnetic field (AMF). Conventional IONCs syntheses are based on thermal decomposition methods, limited by the long reaction time (hours) and milligram‐scale production; while, solvothermal methods produce gram‐scale amount of high quality IONCs, but, reaction times are of the orders of hours. In this work, a microwave‐assisted route to shape‐control IONCs in which the reaction time is reduced to minutes while achieving a high iron conversion yield up to 80% is reported. The size of the IONCs (range 13–30 nm) is coarse‐tuned by adjusting the amount of benzaldehyde ligand, while fine‐size tuning is achieved by changing temperature and minute‐reaction time. IONCs exhibit superparamagnetic behavior at 298 K with saturation magnetization over 80 emu gIONC−1 and possess high specific absorption rate values (SAR) up to 400 W gFe−1 at clinical AMF conditions. These results mark a milestone for rapid synthesis of IONCs at high yield conversion of well‐defined size and shape nanocubes with benchmark MHT heat performance while using a fast route, with limited energy consumption which makes this method greener and cheaper than previous ones.

Magnetically separable Mangifera Indica leaf extract-mediated hematite nanoparticles potentiate cytotoxic activity

In the present report, an environmentally benign, cost-effective, and green route method was adapted to synthesize hematite (α-Fe2O3) nanocrystals (NCs) using Magnifera Indica leaf extract (MILE). Crystal structure characterization of Magnifera Indica leaf extract-mediated hematite nanocrystals [MILE@α-Fe2O3 NCs] showed rhombohedral crystallinity with space group R3¯c as confirmed through the Rietveld refinement method. Microstructural characterization carried out using a transmission electron microscope (TEM) confirmed the nano-dimensional formation of MILE@ α-Fe2O3 NCs with an average size of 3.7 nm as derived from the Gaussian distribution of particle analysis. The optical spectrum shows an absorption peak at 264 nm and another broad hump centered at 383 nm. MILE@α-Fe2O3 NCs exhibit superparamagnetic behavior and also intact reusability ability or recoverable efficiency after being used due to magnetically separation ability. The anticancerous activity of MILE@α-Fe2O3 NCs was carried out against MDA-MB 231 cell lines and it was found that cell viability follows a concentration-dependent manner with a low value of IC50 = 34.70 µg/mL.

Antimicrobial activity of CuFe2O4 and CuFe2O4/ZnO: Squaring colorimetric and traditional microbiology assays with atomic force- and holotomography-microscopies

Intensive research efforts seek the discovery of efficient antimicrobial compounds to fight microbial resistance. Magnetic nanoparticles represent a promising option due to their multifunctional antimicrobial properties, as well as their versatility, stability, and the limited microbial resistance they generate. In this study, magnetic nanomaterials (MNMs) are synthesized using a microwave-activated solvothermal method. Characterization data indicate the crystalline nature (cubic spinel CuFe2O4 NMs), superparamagnetic behavior (MCF = 52 emu/g and MCF-ZnO = 29 emu/g) nanometric and regular size (spherical particles with a mean size of 7.4 ± 1.3 nm) of the MNMs. The antimicrobial activity of the as-prepared (naked) MNMs is moderate against bacteria, yeast, and fungal strains due to the aggregation of the MNMs in the exposure media. However, citrate-functionalized MNMs (CuFe2O4-Cit, CF-Cit) show enhanced antimicrobial activity, further increasing upon activation under a high-frequency magnetic field (magnetic hyperthermia). CF-Cit exerts stronger antibacterial activity towards S. aureus (MIC <25 μg/mL) than E. coli (MIC <50 μg/mL In addition, CuFe2O4-ZnO composites were synthesized and fully characterized. The MNMs under study exhibit efficient antifungal and anti-biofilm activity. Working towards the sustainable development of multifunctional (CuFe2O4 and CuFe2O4-ZnO) MNMs, their compatibility and bioactivity was evaluated using traditional assays and advanced microscopy techniques (Atomic Force Microscopy-AFM and Holotomographic Microscopy -HTM). Because of their chemical composition, the MNMs under study lixiviate transition metal ions to the exposure media, interfering with traditional colorimetric assays used to evaluate the bioactivity of the MNMs (antimicrobial, biocompatibility). Thus, AFM and HTM studies render complementary information during the interpretation of the bioactivity mechanisms exhibited by the MNMs.

Cerium doped superparamagnetic Mn-Zn ferrite as a promising material for self-regulated magnetic hyperthermia

Recently, cubic ferrites (CF) have been widely explored in biomedical applications, especially those that display superparamagnetism behavior due to the desirable absence of remanent field. In this study, we report the self-stabilization of the magnetic fluid hyperthermia (MFH) temperature in the cancer therapy range (42 - 48 ºC) by Ce3+ substitution in superparamagnetic Mn0.8Zn0.2Fe2-xCexO4 ferrite with x = 0.0; 0.015; 0.030; 0.050 and 0.100. A comprehensive characterization was performed in order to investigate the influence of this replacement on the magnetic and structural properties of the ferrite. The samples were synthesized by the sol-gel auto-combustion method and the properties were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), Raman spectroscopy (RS), Mössbauer spectroscopy (MS), vibrational sample magnetometry (VSM), and ferromagnetic resonance (FMR). Magnetic hyperthermia essays were used to obtain the heat induction curves and calculate energy dissipation. We refined the XRD data by the Rietveld method to determine the cation distribution and calculate interionic parameters. Magnetic characterization confirms the superparamagnetic behavior at 300 K, which is expected from the TEM results that show a narrow distribution of particle sizes, with a mean size of about 6.5 nm for all samples. The VSM results show a consistent decrease in magnetization saturation with cerium content that result in a weaker self-heating induction capacity for the cerium-doped samples. FMR results also show a smaller relaxation time T2 for these samples, suggesting a slower energy dissipation rate. These conclusions are confirmed by the heat induction curves and the values of the specific absorption rate (SAR), which are smaller for cerium-doped samples. For the a field with an amplitude of 35.33 kA/m and a frequency of 222 kHz, the temperature of the cerium-doped samples saturates in the optimum interval for cancer treatment, between 42 and 48 ºC. These results suggest that Ce3+ is a promising doping ion to optimize the heating rate behavior of Mn-Zn ferrite for cancer treatment by hyperthermia.

Nanostructured spinel ferrites: A comprehensive study on the synthesis, characterization, and magnetic properties of Zn and Mn substituted magnetite nanoparticles produced through the co-precipitation method

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.

Tuning the physical properties of ternary alloys (NiCuCo) for in vitro magnetic hyperthermia: experimental and theoretical investigation

Most of published research on magnetic hyperthermia focused on iron oxides, ferrites, and binary alloy nanostructures, while the ternary alloys attracted much limited interest. Herein, we prepared NiCuCo ternary alloy nanocomposites with variable compositions by mechanical alloying. Physical properties were fully characterized by XRD, Rietveld analysis, XPS, SEM/EDX, TEM, ZFC/FC and H-M loops. DFT calculations were used to confirm the experimental results in terms of structure and magnetism. The results showed that the fabricated nanoalloys are face centered cubic (FCC) with average core sizes of 9–40 nm and behave as superparamagnetic with saturation in the range 4.67–42.63 emu/g. Langevin fitting corroborated the superparamagnetic behavior, while law of approach to saturation (LAS) was used to calculate the magnetic anisotropy constants. Heating effciencies were performed under an alternating magnetic field (AMF, H0 = 170 Oe and f = 332.5 kHz), and specific absorption rate (SAR) values were determined. The highest magnetic saturation (Ms), heating potentials, and SAR values were attained for Ni35Cu30Co35 containing the lowest Cu but highest Ni and Co percentages, and the least for Ni15Cu70Co15. Importantly, the nanoalloys reached the required temperatures for magnetic hyperthermia (42 °C) in relatively short times. We also showed that heat dissipiation can be simply tuned by changing many parameters such as concentration, field amplitude, and frequency. Finally, cytotoxicity viability assays against two different breast cancer cell lines treated with Ni25Cu50Co25 nanoalloy in the presence and absence of AMF were investigated. No significant decrease in cancer cell viability was observed in the absence of AMF. When tested against tumorigenic KAIMRC2 breast cancer cells under AMF, the NiCuCo nanoalloy was found to be highly potent to the cells (~ 2-fold enhancement), killing almost all the cells in short times (20 min) and clinically-safe AC magnetic fields. These findings strongly suggest that the as-prepared ternary NiCuCo nanoalloys hold great promise for potential magnetically-triggered cancer hyperthermia.

STRUCTURAL, MORPHOLOGICAL AND MAGNETIC PROPERTIES OF FUNCTIONALIZED MANGANESE IRON OXIDE NANOPARTICLES FOR BIOLOGICAL APPLICATIONS

The chitosan functionalized MnFe2O4 nanoparticles were synthesized using thermal decomposition method. The morphological, structural and magnetic properties of obtained chitosan functionalized magnetic nanoparticles were studied to assess the feasibility for biomedical applications. The crystallite size of nanoparticles observed using XRD was 15nm. Functional group attachment to surface of nanoparticles was analyzed using FTIR. Particle size of nanoparticles was studied by TEM analysis and it showed that particles were roughly spherical. Thermal stability and bonding strength of ligands to the surface of material was determined using TGA. The magnetization of chitosan functionalized nanoparticles observed by VSM is 56emu/g and VSM showed no coercivity and remanence existence, stipulating the super-paramagnetic behavior. The cell viability of chitosan functionalized nanoparticles was above 85% at concentration up to the 1.0mg mL-1 on mouse fibroblast cell line i.e. L929 cell line. These studies revealed that, MnFe2O4 nanoparticles are potential materials for biomedical applications.

Influence of rotation on magnetic properties of thin film

Monte Carlo simulation based on the Metropolis algorithm is used to investigate the thermal and magnetic properties of the mixed spin-1/2 and spin-1 Ising model on a double-layer thin film one fixed. The upper layer rotates around the z-axis using the rotation matrix under the influence of different parameters such as the rotational angle, reduced exchange coupling constant, reduced anisotropy constant, and the applied external magnetic field. This study concentrated on examining the interactions between next-neighbor atoms, employing free boundary conditions. The critical and compensation behavior has been investigated by studying phase diagrams, and magnetic and thermodynamic properties such as magnetization, susceptibility, and specific heat. The system showed diverse types of Neel behaviors such as the N-, Q-, and P-type. Moreover, the hysteresis loops of the system have been examined for different values of the exchange interaction constant, temperature, crystal field, and the rotational angle. Finally, the system showed single and triple hysteresis loop behaviors and superparamagnetic behavior.

Supraparticles from Cubic Iron Oxide Nanoparticles: Synthesis, Polymer Encapsulation, Functionalization, and Magnetic Properties.

Supraparticles (SPs) consisting of superparamagnetic iron oxide nanoparticles (SPIONs) are of great interest for biomedical applications and magnetic separation. To enable their functionalization with biomolecules and to improve their stability in aqueous dispersion, polymer shells are grown on the SPs' surface. Robust polymer encapsulation and functionalization is achieved via atom transfer radical polymerization (ATRP), improving the reaction control compared to free radical polymerizations. This study presents the emulsion-based assembly of differently sized cubic SPIONs (12-30 nm) into SPs with diameters ranging from ∼200 to ∼400 nm using dodecyltrimethylammonium bromide (DTAB) as the surfactant. The successful formation of well-defined spherical SPs depends upon the method used for mixing the SPION dispersion with the surfactant solution and requires the precise adjustment of the surfactant concentration. After purification, the SPs are encapsulated by growing surface-grafted polystyrene shells via activators generated by electron transfer (AGET) ATRP. The polymer shell can be decorated with functional groups (azide and carboxylate) using monomer blends for the polymerization reaction. When the amount of the monomer is varied, the shell thickness as well as the interparticle distances between the encapsulated SPIONs can be tuned with nanometer-scale precision. Small-angle X-ray scattering (SAXS) reveals that cubic SPIONs form less ordered assemblies within the SPs than spherical SPIONs. As shown by vibrating sample magnetometer measurements, the encapsulated SPs feature the same superparamagnetic behavior as their SPION building blocks. The saturation magnetization ranges between 10 and 30 emu/g and depends upon the nanocubes' size and phase composition.

Effective removal of Pb(II) ions using Fe3O4/MgO adsorbent: A comprehensive study &amp;nbsp;

The effective removal of heavy metal ions, particularly Pb(II), from contaminated water sources remains a pressing environmental concern. This study explores the potential of Fe3O4/MgO nanocomposites as an efficient adsorbent for selective Pb(II) removal. The Fe3O4/MgO nanocomposite was synthesized using a controlled sol-gel method and characterized using various techniques. X-ray diffraction (XRD) analysis confirmed the presence of cubic MgO and cubic Fe3O4. Pb(II) adsorption induced a crystallographic transformation, forming hexagonal Mg(OH)2 crystals, indicating interaction with the adsorbent. Scanning Electron Microscope (SEM) analysis revealed pyramid-like and irregular crystal morphologies. Pyramid-like structures provided a larger surface area and active sites for effective Pb(II) interaction, while irregular crystal particles, representing magnetic Fe3O4, contributed to stability and dispersibility. Vibrating sample magnetometer (VSM) results confirmed superparamagnetic behaviour with a saturation magnetization of 32.02 emu g-1, indicating potential for magnetic separation and recovery in various wastewater treatment applications. Adsorption experiments utilized optimized conditions: an initial concentration of 600 mg L-1, adsorbent dosage of 0.25 g L-1, pH of 7, and 120 minutes of reaction time. The Fe3O4/MgO nanocomposite exhibited exceptional performance with a remarkable 99.98% removal efficiency and a high adsorption capacity of 2399.44 mg g-1. These impressive results underscore the outstanding adsorption potential of the nanocomposite. Adsorption kinetics followed the pseudo-second-order model (R2 = 0.99), confirming suitability for Pb(II) removal. The Freundlich model indicated a heterogeneous surface with different adsorption sites. Overall, the Fe3O4/MgO nanocomposite exhibits potential as a cost-effective, environmentally friendly adsorbent for removing Pb(II) ions, providing a promising solution for water purification and environmental remediation.

Quantitative Analysis of Ferrate(VI) and Its Degradation Products in Electrochemically Produced Potassium Ferrate for Waste Water Treatment

Potassium ferrate(VI) (K2FeO4) as a particularly strong oxidant represents an effective and environmentally friendly waste water treatment material. When produced by anodic oxidation in highly alkaline aqueous solution, the K2FeO4 product is separated and sealed in inert plastic bags with the retention of some liquid phase with high pH. This method proved to be excellent for long-term storage at moderately low temperature (5 °C) for industrial applications. It is still imperative to check the ferrate(VI) content of the product whenever it is to be used. Fe-57 Mössbauer spectroscopy is an excellent tool for checking the ratio of ferrate(VI) to the degradation product iron(III) in a sample. For this purpose, normally the spectral areas of the corresponding subspectra are considered; however, this approximation neglects the possible differences in the corresponding Mössbauer–Lamb factors. In this work, we have successfully determined the Mössbauer–Lamb factors for the ferrate(VI) and for the most common iron(III) degradation products observed. We have found superparamagnetic behavior and low-temperature phase transformation for another iron(III) degradation product that made the determination of the Mössbauer–Lamb factors impossible in that case. The identities of a total of three different iron(III) degradation products have been confirmed.

Green Chemical Synthesis of Cube‐Shaped CuFe2O4 Nanoparticles for Use as Magnetically Retrievable Catalysts in A3 Coupling Reactions

ABSTRACTA3 coupling reaction is a multicomponent reaction (MCR) involving aryl aldehydes, phenyl acetylenes and amines to synthesize a variety of biologically active propargylamine derivatives. Herein, we report the preparation of cube‐shaped CuFe2O4 nanoparticles (NPs) via the hydrothermal method in the presence of Lantana camara flower (LCF) extract to use them as catalysts to synthesize propargylamine derivatives. X‐ray diffraction study confirms the formation of CuFe2O4 NPs with cubic spinel structures. In the presence of LCF extract, cube‐shaped CuFe2O4 NPs are formed predominantly irrespective of the type of alkali used as the hydrolyzing agent. However, a mixture of nearly spherical and cube‐shaped particles has been formed in the absence of additives. The synthesized CuFe2O4 NPs exhibit superparamagnetic behaviour and are magnetically ordered. The synthesized cube‐shaped CuFe2O4 NPs exhibit excellent catalytic activity in the A3 coupling reaction between benzaldehyde, piperidine and phenylacetylene to give propargylamine with a yield of 90% under the optimum conditions. The catalyst is highly stable and magnetically retrievable facilitating reusability for up to five cycles without considerable loss of catalytic activity. The protocol is suitable for the synthesis of a diverse range of propargylamine derivatives with moderate to excellent yield.

Synthesis, Magnetic, and Photocatalytic Activity of Polypyrrole-Based TiO2–Fe Catalyst for Wastewater Treatment

The primary aim of this study is to investigate the degradation efficacy of the Ppy/TiO2-Fe photocatalyst for MB dye in an aqueous solution. Firstly, the direct addition of TiO2 and Fe was done to prepare Ppy/TiO2-Fe photocatalyst. Fourier transformation infrared spectroscopy, XRD, SEM, BET surface area analysis, and magnetization tests established the formation of the Ppy/TiO2-Fe photocatalyst. The crystallite sizes of TiO2, Fe-TiO2, and Ppy/TiO2-Fe photocatalyst were estimated to be 24.99 nm, 21.94 nm, and 21.84 nm, respectively. For the synthesis confirmation, the FTIR spectrum confirmed the existence of Ti-O, Fe-O, and Ppy-related bonds. While comparing the SEM images, the impact of polypyrrole on the particle shape was observed with less aggregation and increased surface roughness. The VSM analysis revealed that incorporating polypyrrole (Ppy) into Fe-TiO2 significantly enhances its magnetic properties, with Ppy/TiO2-Fe exhibiting superparamagnetic behavior, characterized by a higher saturation magnetization (Ms) of 33.11 emu/g and a lower coercivity (Hc) of 0.160 Oe, compared to Fe-TiO2’s Ms of 1.09 emu/g and Hc of 341.39 Oe. The N2 sorption desorption, with a specific surface area of 2.25 × 102 m2/g, is beneficial for photocatalytic activity. The concentration of dye, amount of catalyst, pH, and temperature were studied to evaluate the photocatalytic efficiency of the synthesized Ppy/TiO2-Fe photocatalyst under different conditions. The findings revealed a degradation efficiency of 91.92%. The degradation rate reached 91.92% under optimal conditions within 120 min and could be fitted well by first-order kinetics. The photocatalytic efficiency was also evaluated for the scavenger, and the concentration of H2O2 and the reusability of the catalyst were demonstrated. Based on the observed results, the Ppy/TiO2-Fe photocatalyst could be applied more effectively and efficiently to photocatalytic degradation of organic dyes in wastewater treatment.

A New Powerful Magnetic Dark Catalyst Based on rGO/Fe3O4/CdSe Nanocomposite for Ultrafast Degradation of Methylene Blue Dye.

In the present study, Rgo/Fe3O4/CdSe as a dark catalyst material was synthesized by a refluxing method. The synthesized magnetic nanocomposites were studied by various analyses such as Fourier transform infrared (FTIR), energy-dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FESEM), X-ray diffractometer (XRD), Raman, Zeta and vibrating sample magnetometer (VSM). Characterization of structural analysis showed that the nanocomposites were successfully synthesized. The absorption spectrum was used to determine the dark catalyst activity of rGO/Fe3O4/CdSe nanocomposite. Analysis of the absorption spectrum showed that the prepared nanocomposites degrade the MB organic dye completely (100%) after 2min of stirring in the dark, also experimenting with different pH showed that the best performance for the degradation of MB occurs in neutral and alkaline media. The Raman spectrum analysis showed that the Fe3O4/CdSe quantum dots (QDs) were correctly incorporated on the reduced graphene oxide (rGO) nanosheets. Zeta potential analysis showed that rGO/Fe3O4/CdSe has a large amount of negative charge on its surface and the surface charge increased by about 16 mV compared to the Fe3O4/CdSe compound. BET and BJH techniques were used to determine the effective surface area and pore size diameter, BET results to determine the effective surface area showed that by adding graphene to the compound, the specific surface area increased from 42.877 m2g-1 to 54.1896 m2g-1. The radical scavenger experiment showed that electrons play an essential role in the degradation process. VSM analysis showed that the prepared nanocomposites have excellent superparamagnetic behavior, this advantage enables the easy collection of nanocatalysts by magnets from wastewater after dye degradation.

A structural, magnetic and colloidal stability study of uncoated and silica coated iron oxide samples prepared in two different surfactants

The discovery of new magnetic materials of interest in the biomedicine field is a relevant topic in current research. For years, our research group has been investigating the obtaining and study of nanostructured magnetic samples that behave superparamagnetically to enable their transport in living organisms. We present here a study that summarizes the structural characteristics, magnetic behavior and stability of two Fe3O4 samples synthesized by coprecipitation that were dispersed using two different surfactants (oleylamine, OL, and oleic acid, OA), and two others prepared from the previous ones by reaction with tetraethyl orthosilicate (TEOS). The relationships between the surfactant used in the synthesis, the presence of a certain maghemite (γ-Fe2O3) content, the influence of silica shell thickness and magnetic behaviour of all samples were systematically studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), Mössbauer spectroscopy and H vs. M loops. Rietveld refinements of the XRD profiles confirmed a partial oxidation of the non-silica-coated samples and FTIR spectra of the uncoated samples showed a very strong broad metal-oxygen band and additional sets of bands from the different organic chains of the two surfactants. Individual particles with a mean diameter of 7 and 9 nm were distinguished in TEM images of uncoated magnetic samples. Mössbauer data indicated the presence of non-stoichiometric magnetite in all samples, in agreement with XRD refinements. Magnetic measurements confirmed the superparamagnetic behavior of all the samples. Highest negative zeta potential values are found for the silica covered samples in both acidic and basic medium, being Fe3O4-AO@SiO2 the best suited for the purposes of its dispersibility in future applications. Low polydispersity index (PDI) values confirmed the best stability and dispersibility of all samples investigated in tetrahydrofuran (THF).

Optimization of Magnetite Nanoparticles for Magnetic Hyperthermia: Correlation with Physicochemical Properties and Cation Distribution

AbstractThe present study reveals the synthesis of Iron oxide nanoparticles (IONPs) by varying the molar ratio of ferric (Fe3+) to ferrous (Fe2+) ions via chemical coprecipitation method for the study of cationic distribution of Fe‐ions and its potential application for magnetic hyperthermia therapy (MHT). X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and X‐ray photoelectron spectroscopy (XPS), were used to characterize the physicochemical properties. Several structural parameters were estimated using the Rietveld refinement, resulting in structural modelling verified by magnetic characteristics. A vibrating sample magnetometer (VSM) assessed the magnetic hysteresis loop at room temperature in a field range of ±15 kOe, revealing superparamagnetic behavior for the ratio Fe2+/Fe3+ 1:2. The saturation magnetization (Ms) of IONPs increased with the increasing Fe2+ concentration and attained a maximum value of 60.21 emu g−1 at a molar ratio of 2:1. The potential of the inductive heating capability of IONPs in an alternating current magnetic field (AMF) was studied to treat localized MHT. The changes in magnetic properties and inductive heating properties of IONPs are associated with the cationic distribution of Fe2+ at the tetrahedral (A) and octahedral (B) sites of crystal structure. The variation in cationic properties at the A and B sites may result in varying/tuneable magnetic properties, affecting the overall heating profiles of hyperthermia.

Structural, Morphology and Electromagnetic Interference Shielding Studies of Multifunctional Hybrids of Low-Density Polyethene with Graphene, Carbon Nanotube and Magnetite

ABSTRACT In this study, we investigate the EMI SE (Electromagnetic interference shielding effectiveness) of novel multifunctional polymer hybrids in the X-band and Ku-band frequencies. Magnetite nanoparticles were synthesized via wet chemical reduction and nanographene was synthesized through chemical exfoliation combined with microwave treatment. Nine different composites were prepared with varying weight ratios of graphene and magnetite. X-ray diffraction (XRD) and scanning electron microscopy (SEM) confirmed their structural and morphological properties. SEM analysis revealed magnetite particle sizes ranging from 10.05 nm to 29.8 nm. Vibrating Sample Magnetometer (VSM) analysis indicated that the magnetite nanoparticles exhibit super paramagnetic behavior with a magnetic anisotropy constant (K) of approximately 63.9375 × 106 J/m3. Impedance analysis, permittivity and permeability measurements showed frequency-dependent behaviors, with interfacial polarization effects due to magnetite agglomeration. The highest conductivity, observed in the 50:5:37.5:7.5 hybrid, peaked at 8 S/cm at lower frequencies. The 50:5:37.5:7.5 hybrid demonstrated the highest EMI SE of 50.08 dB (99.999019% suppression) in the X-band, which is suitable for advanced EMI-shielding applications.

Unraveling the properties of [TPA]2Cu2Br6: A holistic investigation into structure, optics, magnetism and dielectric characteristics

The recent technological advances require an aligned innovation in the materials used for the construction of electronic devices. Hybrid materials play a important role in the optoelectronic applications because they combine both the organic and inorganic components To this end, the [TPA]2Cu2Br6 compound was successfully synthesized using the slow evaporation solution growth approach at room temperature. The [TPA]2Cu2Br6 compound crystallizes in the triclinic system with P1‾space group. The atomic arrangement can be described by an alternation of organic and inorganic layers stacked along the c direction and made up of [N(C3H7)4]+ and [CuBr3]− groups, respectively. The examination of SEM analysis allows us to raise the morphology and the good quality of the crystals. The EDX analysis was performed to ensure that all chemical elements were discovered and located in the relevant locations.For the compound under study, the UV–visible spectroscopy spectrum shows the direct band-gap value of ∼3.52 eV, indicating that it is a semiconductor material. Magnetic measurements revealed the superparamagnetic behavior. Studies of the dielectric constant permittivity ε*(ω) confirmed that the relaxation process was thermally activated. The dominant transport mechanism is the s the non-overlapping small polaron tunneling (NSPT) model.

Evaluation of magnetic hyperthermia, drug delivery and biocompatibility (bone cell adhesion and zebrafish assays) of trace element co-doped hydroxyapatite combined with Mn-Zn ferrite for bone tissue applications.

The treatment and regeneration of bone defects, especially tumor-induced defects, is an issue in clinical practice and remains a major challenge for bone substitute material invention. In this research, a composite material of biomimetic bone-like apatite based on trace element co-doped apatite (Ca10-δ M δ (PO4)5.5(CO3)0.5(OH)2; M = trace elements of Mg, Fe, Zn, Mn, Cu, Ni, Mo, Sr and BO3 3-; THA)-integrated-biocompatible magnetic Mn-Zn ferrite ((Mn, Zn)Fe2O4 nanoparticles, BioMags) called THAiBioMags was prepared via a co-precipitation method. Its characteristics, i.e., physical properties, hyperthermia performance, ion/drug delivery, were investigated in vitro using osteoblasts (bone-forming cells) and in vivo using zebrafish. The synthesized THAiBioMags particles revealed superparamagnetic behaviour at room temperature. Under the influence of an alternating magnetic field, THAiBioMags particles demonstrated a change in temperature, indicating their potential for magnetic hyperthermia, in which THAiBioMags further exhibited a specific absorption rate (SAR) value of 9.44 W g-1 (I = 44 A, H = 6.03 kA m-1 and f = 130 kHz). In addition, the as-prepared particles demonstrated sustained ion/drug (doxorubicin (DOX)) release under physiological pH conditions. Biological assay analysis revealed that THAiBioMags exhibited no toxicity towards osteoblast cells and demonstrated excellent cell adhesion properties. In vivo studies employing an embryonic zebrafish model showed the non-toxic nature of the synthesized THAiBioMags particles, as revealed by evaluation of the survivability, hatching rate, and embryonic morphology. These results could potentially lead to the design and fabrication of magnetic scaffolds to be used in therapeutic treatment and bone regeneration.

Photocatalytic degradation of rhodamine B using Yb3+-Doped Zn-Mg ferrites synthesized via conventional sol-gel auto-combustion method

The primary goal of our research is to develop a photocatalyst capable of degrading organic molecules in water, achieved through the rare earth Yb3+ doping of Zn-Mg spinel ferrites. A key element of our approach is the use of the conventional sol-gel auto-combustion process, which has proven to be an effective method for synthesizing a high-performing, visible light-driven Zn0.9Mg0.1Fe2-xYbxO4 (x = 0.000, 0.015, 0.030, 0.045, 0.060 and 0.075) nano-ferrites. Many analytical techniques were employed to evaluate the material's physicochemical characteristics, including P-XRD, EDX, FE-SEM, HR-TEM, FTIR, UV–vis, BET, VSM, EIS, and photocatalysis was carried out against the RhB. The impact of Yb3+ ion doping on the material's crystallite size and lattice parameter has been evaluated. It was found that all the samples' crystallite sizes increased between 33 and 41 nm. These magnetite nanoparticles have spherical forms and nanometric particle sizes, as revealed through field scanning electron microscopy (FE-SEM). The FTIR spectra bands at ʋ1 (518–535) and (401–411) ʋ2 subsequently revealed the spinel structure of the synthesized nano-ferrites. The band gap in zinc manganese ferrite increases from 2.51 eV to 2.92 eV after adding ytterbium. The surface area of the Yb3+-doped Zn-Mg ferries ranges from 23.6 m2/g to 27.8 m2/g, making them an excellent choice for data storage. The investigation of magnetic behavior shows the superparamagnetic behavior of all the samples. The produced sample's determined squareness value indicates the magnetostatic interaction between the particles. Because of the low produced coercive field value, these materials can be used in ferrofluids and hyperthermia therapy applications. Furthermore, with a higher RhB removal of 93.80 %, the Yb3+-doped sample photocatalyst successfully separated carriers generated by sunlight. The Yb3+-doped sample (ZMY-5) photocatalyst showed outstanding stability after one cycle of the stability test, obtaining an outstanding RhB elimination of 93.80 %. Zn0.9Mg0.1Yb0.075Fe1.925O4 photocatalyst has substantial promise for large-scale pollutant treatment due to its simple synthesis method, superior magnetic characteristics, exceptional photocatalytic activity for RhB, and excellent stability.