Magnetically separable Zn1−xCo0.5xMg0.5xFe2O4 ferrites: stable and efficient sunlight-driven photocatalyst for environmental remediation

Synthesis of New Complex Ferrite Li0.5MnFe1.5O4: Chemical-Physical and Electrophysical Research

In this article, the sol-gel method was used as a synthesis method, which shows the physicochemical nature of the synthesis of a new complex material, ferrite Li0.5MnFe1.5O4. The structure and composition of the synthesized ferrite were determined by X-ray phase analysis. According to analysis indicators, it was found that our compound is a single-phase, spinel-structured, and syngony-cubic type of compound. The microstructure of the compound and the quantitative composition of the elements contained within it were analyzed under a scanning electron microscope (SEM). Under a scanning electron microscope, microsystems were taken from different parts of Li0.5MnFe1.5O4-type crystallite; the elemental composition of crystals was analyzed; and the general type of surface layer of complex ferrite was shown. As a result, given the fact that the compound consists of a single phase, the clarity of its construction was determined by the topography and chemical composition of the compound. As a result, it was found that the newly synthesized complex ferrites correspond to the formula Li0.5MnFe1.5O4. The particles of the formed compounds have a large size (between 50.0 μm or 20.0 μm and 10.0 μm). Electrophysical measurements were carried out on an LCR-800 unit at intervals of 293-483 K and at frequencies of 1.5 and 10 kHz. An increase in frequency to 10 kHz led to a decrease in the value ε in the range of the studied temperature (293-483 K).

Tuning the Magnetic Behavior of Zinc Ferrite via Cobalt Substitution: A Structural Analysis

Cobalt-doped zinc ferrite is a contemporary material with significant structural and magnetic characteristics. Our study explores the magnetic properties of cobalt-substituted zinc ferrite (ZnxCo1-xFe2O4), synthesized via a simple sol-gel method. By varying the cobalt ratio from 0 to 0.5, we found that zinc substitution impacts both the magnetization and lattice parameters. FTIR analysis suggested the presence of functional groups, particularly depicting an M-O stretching band, within octahedral and tetrahedral clusters. X-ray diffraction analysis confirmed the phase purity and cubic structure. The synthesized materials exhibited an average particle size of 24-75 nm. Scanning electron microscopy revealed the morphological properties, confirming the formation of truncated octahedral particles. In order to determine the stability, mass loss (%), and thermal behavior, a thermal analysis (thermogravimetric analysis (TGA)/differential thermal analysis (DTA)) was performed. The magnetic properties of the synthesized ferrites were confirmed via a vibrating sample magnetometer (VSM). Finally, the highest saturated magnetization and lowest coercivity values were observed with higher concentrations of the cobalt dopant substituting zinc. The synthesized nanomaterials have good stability as compared to other such materials and can be used for magnetization in the near future.

Impact of Mn-Ni spinal ferrite nanoparticles on the structural, morphological, surface roughness, and optical parameters of polyvinyl alcohol for optoelectronic applications

Herein, polyvinyl alcohol (PVA) acts as a host matrix for manganese-nickel ferrite (Mn0.4Ni0.6Fe2O4) nanoparticles (NPs). Oxalate precursors and a solution-cast method were used to produce a Mn0.4Ni0.6Fe2O4 spinel structure and PVA-Mn0.4Ni0.6Fe2O4 films, respectively. X-ray diffraction (XRD), scanning electron microscopy, optical microscopy (OM), a surface roughness tester, and FT-IR spectroscopy were used to identify the structure and morphology of the PVA-Mn0.4Ni0.6Fe2O4 films. XRD confirmed the formation of Mn0.4Ni0.6Fe2O4 spinel, and its additive into the PVA matrix causes an increase in the PVA amorphousity. The PVA-Mn0.4Ni0.6Fe2O4 film's transmission and absorption spectra were recorded with the help of a UV-visible spectrophotometer. The addition of 4%Mn0.4Ni0.6Fe2O4 to PVA resulted in a decrease in the optical bandgap from 5.53 eV to 4.83 eV. The Urbach energy increases from 0.46 eV for pure PVA to 2.14 eV for PVA-4%Mn0.4Ni0.6Fe2O4, indicating a rise in the defect density. In addition, the refractive index and extinction coefficient were calculated theoretically and were found to increase as the Mn0.4Ni0.6Fe2O4 content increases in the PVA matrix.

Research on the physical properties of LiMn0.5Fe2O4 spinel ferrites by the combination of optical, magnetic, and dielectric behaviors

Ferrite compounds have recently attracted significant interest because of their multifunctional properties. This work investigates the optical, magnetic, and dielectric properties of a LiMn0.5Fe2O4 ferrite prepared by a solid-state reaction. Raman spectroscopy analysis substantiated the presence of the 5 active modes representing the vibration of the oxygen anion at both tetrahedral and octahedral sites. The direct optical band gap was estimated to be 3.51 eV, which indicates the semiconductor behavior of the compound. A theoretical modulation of the hysteresis loop was done to confirm the dominance of the ferromagnetic contribution over the antiferromagnetic one. Furthermore, the dielectric permittivity result indicated a colossal value of the order of 103. The dielectric losses are characterized by the Giuntini law to extract the relaxation process, which is hidden by the DC-conductivity process. Our results indicate the potential of LiMn0.5Fe2O4 for applications in multifunctional devices.

Fabrication and Characterization of W-Substituted ZnFe2O4 for Gas Sensing Applications

A sol–gel technique was successfully employed in creating pure and W-substituted zinc ferrite, with nominal compositions of ZnFe2−2xWxO4 (0.0 ≤ x ≤ 0.15). For the purposes of investigating the physical and chemical properties of the generated powders, several analytical techniques were used. In TEM images of all the compositions, mixed-shaped particles (cubic, spherical, and hexagonal) were observed. The crystallite size decreases from 82 nm (x = 0.0) to 32 nm (x = 0.15) with an increase in the W doping contents in the ZnFe2O4 lattice. The microstrain increases with increasing W doping content. Furthermore, the surface area of pure ZnFe2O4, 0.05 W-ZnFe2O4, 0.10 W-ZnFe2O4, and 0.15 W-ZnFe2O4 NPs were calculated as being 121.5, 129.1, 134.4 and 143.2 m2 g−1, respectively, with a mesoporous pore structure for all ferrite samples. The calculated BJH pore size distribution was within the range of 160 to 205 Å. All W-doped ZnFe2O4 samples show H-M loops with paramagnetic characteristics. The magnetization (M) directly increases by increasing the applied field (H) without achieving saturation up to 20 kA/m. For comparison, the magnetization at 20 kA/m gradually decreases with increasing W doping content. Among all the synthesized samples, the 0.15 W-ZnFe2O4 NPs demonstrated the highest sensitivity towards acetone gas at 350 °C.

High-Performance, Lightweight, and Flexible Thermoplastic Polyurethane Nanocomposites with Zn2+-Substituted CoFe2O4 Nanoparticles and Reduced Graphene Oxide as Shielding Materials against Electromagnetic Pollution

The development of flexible, lightweight, and thin high-performance electromagnetic interference shielding materials is urgently needed for the protection of humans, the environment, and electronic devices against electromagnetic radiation. To achieve this, the spinel ferrite nanoparticles CoFe2O4 (CZ1), Co0.67Zn0.33Fe2O4 (CZ2), and Co0.33Zn0.67Fe2O4 (CZ3) were prepared by the sonochemical synthesis method. Further, these prepared spinel ferrite nanoparticles and reduced graphene oxide (rGO) were embedded in a thermoplastic polyurethane (TPU) matrix. The maximum electromagnetic interference (EMI) total shielding effectiveness (SET) values in the frequency range 8.2-12.4 GHz of these nanocomposites with a thickness of only 0.8 mm were 48.3, 61.8, and 67.8 dB for CZ1-rGO-TPU, CZ2-rGO-TPU, and CZ3-rGO-TPU, respectively. The high-performance electromagnetic interference shielding characteristics of the CZ3-rGO-TPU nanocomposite stem from dipole and interfacial polarization, conduction loss, multiple scattering, eddy current effect, natural resonance, high attenuation constant, and impedance matching. The optimized CZ3-rGO-TPU nanocomposite can be a potential candidate as a lightweight, flexible, thin, and high-performance electromagnetic interference shielding material.

Highly efficient visible light driven photocatalytic activity of zinc/ferrite: Carbamazepine degradation, mechanism and toxicity assessment

In this present study, spherical shaped zinc ferrite (Zn/Fe₂O₄) was prepared as uniformly sized (65 ± 0.5 nm) nanoparticles with band gap (2.00 eV) in a visible light regime and employed for the photocatalytic degradation of carbamazepine (CBZ). The doping of Zn decreased the band gap (from 2.00 to 1.98 eV) and enhanced the absorption of visible light. Zinc doping also induced effective separation of photogenerated carriers and subsequent charge migration to the surface of the Zn/Fe₂O₄ nanoparticle. On account of the advantages of the material, a high removal efficiency (~ 100%) of CBZ through photocatalytic degradation was achieved. Kinetics of CBZ degradation follows a pseudo first-order with the rate constant 0.0367 min^-1. In-vitro and in-vivo toxicity of the nanoparticles were examined promoting the environmental implications.