Zinc Ferrite Nanoparticles Research Articles

Superparamagnetic characteristic of surface capped Mg0.5Zn0.5Fe2O4 nanoparticles reinforced polycarbonate nanocomposite fibers with mixed magnetic phases

The purpose of this work is to prepare magnetic polycarbonate nanocomposite fibers from nonmagnetic polycarbonate material by electrospinning method. This was achieved by the incorporation of oleic acid capped magnesium zinc ferrite (Mg0.5Zn0.5Fe2O4) nanoparticles during the spinning process. The presence of uniformly distributed surface capped Mg0.5Zn0.5Fe2O4 nanoparticles in the polymer nanofibers was detected by TEM investigation. The nanocomposite fibers retained and exhibited the excellent surface morphology as that of the plane polycarbonate fibers prepared under the same solution and spinning parameters. FT-IR and XRD studies revealed that, there did not happen any degradation to the polycarbonate material even with a high nanofiller load or under a high applied potential during electrospinning. UV-Visible spectral study shows that the polycarbonate nanocomposite fibers attained attractive visible light absorption power. The increased polymer entanglement by the proper interaction with the ferrite nanoparticles attributes to the increase in the glass transition temperature of the nanocomposite fibers. The VSM analysis was carried out to find the magnetic parameters like saturation magnetization, coercivity and retentivity of the composite fibers. Mossbauer spectral analysis was done to know the isomer shift, quadrupole splitting and the average hyperfine field. PC-Mg0.5Zn0.5Fe2O4 composite nanofibers exhibit quadrupole splitting values between 0.35 and 0.57 mm/s

Development of a thermochromic lateral flow assay to improve sensitivity for dengue virus serotype 2 NS1 detection.

Dengue disease is a viral infection that has been widespread in tropical regions, such as Southeast Asia, South Asia and South America. A worldwide effort has been made over a few decades to halt the spread of the disease and reduce fatalities. Lateral flow assay (LFA), a paper-based technology, is used for dengue virus detection and identification because of its simplicity, low cost and fast response. However, the sensitivity of LFA is relatively low and is usually insufficient to meet the minimum requirement for early detection. In this study, we developed a colorimetric thermal sensing LFA format for the detection of dengue virus NS1 using recombinant dengue virus serotype 2 NS1 protein (DENV2-NS1) as a model antigen. Plasmonic gold nanoparticles, including gold nanospheres (AuNSPs) and gold nanorods (AuNRs), and magnetic nanoparticles (MNPs), namely iron oxide nanoparticles (IONPs) and zinc ferrite nanoparticles (ZFNPs), were studied for their thermal properties for sensing assays. AuNSPs with 12 nm diameter were chosen due to their great photothermal effect against light-emitting diodes (LEDs). In the thermal sensing assay, a thermochromic sheet is used as a temperature sensor transforming heat into a visible colour. In the typical LFA, the test line is visible at 6.25 ng mL-1 while our thermal sensing LFA offers a visual signal that can be observed at as low as 1.56 ng mL-1. The colorimetric thermal sensing LFA is capable of reducing the limit of detection (LOD) of DENV2-NS1 by 4 times compared to the typical visual readout. The colorimetric thermal sensing LFA can enhance the sensitivity of detection and deliver visuality to the user to translate without the need for an infrared (IR) camera. It has the potential to expand the utilities of LFA and satisfy early diagnostic applications.

A novel nanocomposite containing zinc ferrite nanoparticles embedded in carboxymethylcellulose hydrogel plus carbon nitride nanosheets with multifunctional bioactivity.

A novel and biologically active nanobiocomposite is synthesized based on carbon nitride nanosheet (g-C3N4) based carboxymethylcellulose hydrogels with embedded zinc ferrite nanoparticles. Physical-chemical aspects, morphological properties, and their multifunctional biological properties have been considered in the process of evaluation of the synthesized structure. The hydrogels' compressive strength and compressive modulus are 1.98 ± 0.03 MPa and 3.46 ± 0.05 MPa, respectively. Regarding the biological response, it is shown that the nanobiocomposite is non-toxic and biocompatible, and hemocompatible (with Hu02 cells). In addition, the developed material offers a suitable antibacterial activity for both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli).

Photocatalytic Degradation of Crystal Violet Dye in Aqueous Solution using ZnFe2O4-Cellulose Nanocomposite Catalyst

The major issue in the modern area is the wastewater discharge, particularly the organic pigments from several industries, which creates various pernicious health hazards. As a result, synthesized zinc ferrites and cellulose nanocomposites are effective photocatalysts used for the detoxification of crystal violet dyes. The crystallite-size of synthesized zinc ferrite nanoparticle was confirmed from XRD by using Scherrer equation to be 25.5 nm. The elemental composition of the zinc ferrite-cellulose nanocomposite was clearly shown by the EDS spectrum. Based on the FESEM micrographs, the zinc ferrite-cellulose nanocomposite morphology revealed a smooth surface with microspheres measuring 500 nm in size. The ZnFe2O4-cellulose nanocomposite demonstrated 92% photocatalytic efficiency for the removal of crystal violet dye at pH 6 after 160 min of sunlight irradiation with a catalyst dosage of 50 mg and an initial dye concentration of 10 ppm. The pseudo-second-order kinetic model was found to be consistent for the photocatalytic process. Finally, the newly developed photocatalyst (ZnFe2O4-cellulose nanocomposites) should be considered better for dye decontamination in wastewater

Synthesis, Structural and Antibacterial Activity of Zn1-xNixFe2O4 Nanoparticles

In present work, nickel doped zinc ferrite nanoparticles were prepared via hydrothermal technique. The prepared nanopowders were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier-transform infrared spectroscope (FTIR), vibrating sample magnetometer (VSM) and antimicrobial activity. The XRD analysis revealed that the presence of sharp diffraction peaks and cubic-structure of the prepared samples. SEM analysis revealed that there is a significant degree of agglomeration in the samples, whereas VSM studies revealed the magnetic behaviour and cation distribution in the prepared samples. The prepared nanopowder has also been evaluated for its antimicrobial properties against Gram-negative bacteria (Enterobacter aerogenes) and Gram-positive bacteria (Enterococcus faecalis). An increasing in the ratio of nickel to zinc in ferrite nanoparticles led to an evident rise in their activity. These nanoparticles with enhanced structure and antimicrobial properties could find applications in hygiene, therapeutic and textile fields.

Synthesis and Characterization of Mixed Metal Oxide Nanoparticles using Thin Film Electroplating Method

An attempt has been made in this work to synthesise an effective mixed metal oxide – zinc ferrite (ZnFe2O4) nanoparticles, coated on a substrate material, by Thin film electroplating technique. The prepared samples were subsequently characterized using X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Electrochemical performance analysis techniques. The XRD pattern has revealed the crystalline dimensions. Surface analysis has been carried out using FESEM and Cyclic Voltammetry has been employed for electrochemical studies of the prepared samples.

Band gap and pseudocapacitance of Gd2O3 doped with Ni0.5Zn0.5Fe2O4

Herein, we present a detailed study of the structural, optical, and electrochemical responses of Gd2O3 doped with nickel zinc ferrite nanoparticles. Doping of Ni0.5Zn0.5Fe2O4 nanoparticles to Gd2O3 powder was done through thermal decomposition at 1000 °C. The average grain size of the mixture was determined to be approximately 95 nm, and phases of cubic Gd2O3, GdO, and orthorhombic prisms of GdFeO3 were identified. The focused ion beam energy dispersive x-ray spectrum (FIB-EDX) mapping results clearly show the morphology of the particles with Gd and Fe as the dominant elements. The structural data were compared with the spectroscopic measurements confirming the formation of multiple phases of oxides and ferrites. The measured optical band gap is significantly redshifted to 1.8 eV and is close to that of nitride compounds of gadolinium metal. The measured specific capacitance was almost 7 Fg−1 at a current density of 1 Ag−1, showing a small drop of 27% when the current density is increased to 10 Ag−1. Cyclic voltammetry (CV) plots of the ferrite doped Gd2O3 electrode at a scan rate of 5 to 100 mV s−1 indicate the pseudocapacitive nature of the material.

ZnFe2O4 nanocomposite films for electromagnetic-triboelectric-piezoelectric effect-based hybrid multimodal nanogenerator

Hybridizing the pre-existing energy harvesting techniques in a single device is in focus nowadays to improve the electrical output of energy harvesting device. This work uses a versatile nanocomposite films comprises cuboctahedron zinc ferrite nanoparticles (CZF NPs) and polymer matrix as energy harvesting layers to implement a hybrid multimodal nanogenerator (HNG) of a triboelectric nanogenerator (TENG), a piezoelectric nanogenerator (PENG), and an electromagnetic nanogenerator (EMG). Polydimethylsiloxane (PDMS) and polyvinylidene fluoride (PVDF) were used as polymer matrix materials of two different nanocomposite films. With embedded multi-spiral coil structuring, CZF NPs @PDMS composite film works for the EMG and the TENG. Furthermore, ferroelectric CZF NPs @PVDF composite film produces piezoelectric output by pushing force, serving as the PENG. Our HNG provides an efficient multimodal energy harvesting as the integrated nanogenerators generate high output power with not only high output voltage, but also low internal electrical impedance with three different working modes including non-contact mode, contact-separation mode, and non-separation mode in response to the external mechanical pushing force and its release. We believe that these techniques can realize the commercial application of flexible hybrid nanogenerators.

ZnFe2O4 spinel oxide incorporated photoanodes as light-absorbing layers for dye-sensitized solar cells

Herein, nanoparticles of zinc ferrite (ZnFe2O4) were initially synthesized by chemical co-precipitation method followed by ultrasonication. Then mixed with TiO2 (P25), and subsequently used as photoanode for dye-sensitized solar cell. ZnFe2O4 nanocomposites were found to be active in the visible region of the solar spectrum, while P25 showed absorption in the UV region, demonstrating a possibility of wider absorption band and higher photoelectric conversion efficiency. Composite photanode (with 0.1 wt% ZnFe2O4) based cell showed high power conversion efficiency (PCE) of 4.55%, whereas, the PCE of the cell with pure TiO2 as photoanode was 3.27%. Thus, there was an 39% enhancement of PCE for the composite photanode based cell..

Redshift of the optical gap in ferrite doped Gd2O3

We report the measurement of the optical bandgap in ferrite doped Gd2O3. Doping of the nickel zinc ferrite (Ni0.5Zn0.5Fe2O4) nanoparticles to Gd2O3 powder was done through thermal decomposition of the mixture at 1000 °C. The average grain size of the thermally decomposed mixture was determined to be around 95 nm and contained phases of cubic Gd2O3, GdO, and orthorhombic prisms of GdFeO3. The imaginary part of the complex dielectric function was calculated from the absorbance measurements that showed an optical bandgap at 1.8 eV. The observed value of the fundamental energy gap is on average 4.0 eV smaller than suggested by early experiments. A model for the ferrite doped Gd2O3 was constructed to suggest that the Ni, Zn, and Fe atoms occupy Gd sites in the Gd2O3 lattice. A new band at Γ point is formed due to the hybridization of the atomic orbitals of dopant and Gd3+ that shifts the fundamental absorption edge to the red part of the photon energy spectrum. Despite having a high density of negatively charged carriers contributed by the dopant, the onset of the direct interband transitions is clearly resolved.

Zinc ferrite nanoparticles embedded in hydroxyapatite for magnetic hyperthermia and sensitive to ionizing radiation

Here we report the development of a bifunctional magnetic composite that induces magnetic hyperthermia and shows stable paramagnetic defects after the irradiation with X-ray source. The composite is formed by Zn0.16Fe2.84O4 nanoparticles of 18 (3) nm of diameter embedded in a micrometric carbonated hydroxyapatite matrix. As the magnetic nanoparticles are fixed in the matrix, their magnetic properties were adjusted by the size and composition in order to induce local heating by magnetic losses in presence of an AC magnetic field due to the Néel relaxation mechanism. This behavior was confirmed by measuring the Specific Power Absorption (SPA) of 0.1 wt% of magnetic nanoparticles dispersed in media with different viscosity as chloroform (η = 0.56 cP) and butter oil (η = 174 cP) obtaining ~111(15) W/g in both cases. Consistently, the magnetic hydroxyapatite composite presents a comparable SPA= 126(19) W/g value. On the other hand, the carbonated hydroxyapatite and the magnetic carbonated hydroxyapatite composite were subjected to X-ray radiation with an equivalent dose of 3 kGy and the generated paramagnetic defects were evaluated by electron paramagnetic resonance spectroscopy. It was observed that the CO2− radical is the main defect produced by the irradiation, and its concentration stabilized after a month. These results confirm the potential of this composite to act as a local nanoheater and as a sensor of ionizing radiation, showing interesting possibilities to be used in studies of nanomedicine where the combination of magnetic hyperthermia and radiotherapy is proposed for oncological treatments.

Development of zinc ferrite nanoparticles with enhanced photocatalytic performance for remediation of environmentally toxic pharmaceutical waste diclofenac sodium from wastewater

Diclofenac sodium is an anti-inflammatory drug commonly used to cure pain in various treatments. The remarkable potential of this pain-killer leads to its excessive use and, therefore, a persistent water contaminant. Its presence in aqueous bodies is hazardous for both humans and the environment because it causes the growth of harmful drug-resistant bacteria in water. Herein, we present a comparative study of the ZnO and ZnFe2O4 as photocatalysts for the degradation of diclofenac sodium, along with their structural and morphological studies. A simple co-precipitation method was used for the synthesis of ZnO and ZnFe2O4 and characterized by various analytical techniques. For instance, the UV–Vis study revealed the absorption maxima of ZnO at 320 nm, which was shifted to a longer wavelength region at 365 nm for zinc ferrite. The optical band gaps obtained from the Tauc plot indicated that the incorporation of iron has led to a decreased band gap of zinc ferrite (2.89 eV) than pure ZnO (3.14 eV). The metal-oxygen linkages shown by FTIR indicated the formation of desired ZnO and ZnFe2O4, which was further confirmed by XRD. It elucidated the typical hexagonal structure for ZnO and spinel cubic structure for ZnFe2O4 with an average crystallite of 31 nm and 44 nm for ZnO and ZnFe2O4, respectively. The micrographs obtained by SEM showed rough spherical particles of ZnO, whereas for ZnFe2O4 flower-like clustered particles were observed. The photocatalytic investigation against diclofenac sodium revealed the higher degradation efficiency of ZnFe2O4 (61.4%) in only 120 min, whereas ZnO degraded only 48.9% of the drug. Moreover, zinc ferrite has shown good recyclability and was stable up to five runs of photodegradation with a small loss (3.9%) of photocatalytic activity. The comparison of two catalysts has suggested the promising role of zinc ferrite in wastewater remediation to eliminate hazardous pharmaceuticals.

Enhanced Magnetic Hyperthermia Performance of Zinc Ferrite Nanoparticles under a Parallel and a Transverse Bias DC Magnetic Field.

The collective organization of magnetic nanoparticles (MNPs) influences significantly their hyperthermic properties, relevant for their in vitro and in vivo applications. We report a systematic investigation of the effects of the concentration and the static bias direct current (DC) magnetic field superposed over the alternating magnetic field (AMF), both in a parallel and perpendicular configuration, on the specific absorption rate (SAR) by using zinc ferrite MNPs. The nonmonotonic dependence of the SAR on the concentration, with a maximum at very small concentrations (c ≤ 0.1 mgFe/mL), followed by a minimum at 0.25 mgFe/mL, and the second maximum of 3.3 kW/gFe at around 1 mgFe/mL, was explained by the passage of the MNPs from a single particle behavior to a collective one and the role of the dipolar interactions. By superposing a static 10 kA/m bias DC field on the AMF we obtained an increase in the SAR for both parallel and perpendicular orientations, up to 4285 W/gFe and 4070 W/gFe, respectively. To the best of our knowledge, this is the first experimental proof of a significant enhancement of the SAR produced by a perpendicular DC field. The effect of the DC field to increase the SAR is accompanied by an increase in the hyperthermia coercive field (HcHyp) for both configurations. No enhancement of the DC fields was noticed for the MNPs immobilized in a solid matrix but the DC field increases the HcHyp only in the parallel configuration. This translates into a higher SAR value for the perpendicular configuration as compared to the parallel configuration. These results have practical applications for magnetic hyperthermia.

Synthesis of ZnFe2O4 nanoparticles with different morphologies via thermal decomposition approach and studies on their magnetic properties

In the present study, zinc ferrite nanoparticles with various morphologies were synthesized by thermal decomposition of Zn-Fe glycolates (precursors) prepared under different synthetic conditions. The ZnFe2O4 nanoparticles and Zn-Fe glycolates were characterized using different analytical techniques like P-XRD, FT-IR, TGA, FE-SEM, TEM, EDXA, DRS and XPS. Rietveld refinement method was used to understand the distribution of Zn2+ and Fe3+ in tetrahedral and octahedral sites of zinc ferrite. The magnetic properties (saturation magnetization, remanence and coercivity) of ZnFe2O4 nanoparticles were investigated at 300 K and 15 K. The ZnFe2O4 nanoparticles exhibit superparamagnetic behavior at 300 K and soft ferromagnetic behavior at 15 K.

Construction of a Well-Defined S-Scheme Heterojunction Based on Bi-ZnFe2O4/S-g-C3N4 Nanocomposite Photocatalyst to Support Photocatalytic Pollutant Degradation Driven by Sunlight

Currently, organic dyes and other environmental contaminants are focal areas of research, with considerable interest in the production of stable, high-efficiency, and eco-friendly photocatalysts to eliminate these contaminants. In the present work, bismuth-doped zinc ferrite (Bi-ZnFe2O4) nanoparticles (NPs) and bismuth-doped zinc ferrites supported on sulfur-doped graphitic carbon nitride (Bi-ZnFe2O4/S-g-C3N4) (BZFG) photocatalysts were synthesized via a hydrothermal process. SEM, XRD, and FTIR techniques were used to examine the morphological, structural, and bonding characteristics of the synthesized photocatalysts. The photocatalytic competence of the functional BZFG nanocomposites (NCs) was studied against MB under sunlight. The influence of Bi (0.5, 1, 3, 5, 7, 9, and 11 wt.%) doping on the photocatalytic performance of ZnFe2O4 was verified, and the 9%Bi-ZnFe2O4 nanoparticles exhibited the maximum MB degradation. Then, 9%Bi-ZnFe2O4 NPs were homogenized with varying amounts of S-g-C3N4 (10, 30, 50, 60, and 70 wt.%) to further enhance the photocatalytic performance of BZFG NCs. The fabricated Bi-ZnFe2O4/30%S-g-C3N4 (BZFG-30) composite outperformed ZnFe2O4, S-g-C3N4 and other BZFG NCs in terms of photocatalytic performance. The enriched photocatalytic performance of the BZFG NCs might be ascribed to a more efficient transfer and separation of photo-induced charges due to synergic effects at the Bi-ZnFe2O4/S-g-C3N4 interconnection. The proposed modification of ZnFe2O4 using Bi and S-g-C3N4 is effective, inexpensive, and environmentally safe.

Facile adsorptive removal of dyes and heavy metals from wastewaters using magnetic nanocomposite of zinc ferrite@reduced graphene oxide

• Incorporation of ZnFe 2 O 4 onto rGO improves the adsorption efficiency of rGO. • Pb (II) and MB dye were efficiently adsorbed onto the synthesized MrGO. • Adsorption of Pb(II) and MB onto MrGO follow Langmuir isotherm and PSO kinetic models. • The synthesized MrGO nanocomposite have been used for 5 consecutive cycles. Graphene-based nanomaterials can be tailored as green and excellent adsorbents for wastewater treatment. Herein, reduced graphene oxide was synthesized by a modified Hummer’s method and decorated with zinc ferrite nanoparticles for the efficient adsorptive removal of lead, and methylene blue dye from aqueous solutions. The characteristics of the nanocomposite adsorbent (ZnFe 2 O 4 @rGO, MrGO) were ascertained by various physicochemical tools including: X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Field Emission scanning electron microscopy with energy dispersive X-ray spectrometry (FESEM-EDX), X-ray photoelectron spectroscopy (XPS), Zeta potential, and Vibrating sample magnetometer (VSM) analysis. Various parameters, influencing the adsorptive removal of pollutants, were thoroughly explored and optimized including the mass of adsorbent, initial concentration of adsorbate, and medium pH. The synthesized MrGO nano-adsorbent exhibited excellent adsorption capacities towards model pollutants of lead ions and methylene blue dye of 89.8 and 119.0 mg g −1 , respectively. A plausible mechanism of pollutants’ removal on the synthesized nanocomposite was attributed mainly to the vacancy defects and oxygen bearing functional groups of the MrGO nanoparticles’ surfaces. The adsorption isotherms conformed to the Langmuir, rather than the Freundlich, model and followed the PSO kinetic model suggesting a chemisorption process via pollutants monolayers on the MrGO nanoparticles’ surfaces. The synthesized MrGO nanocomposite was excellently stable and reusable for five consecutive cycles; and therefore, it can be a promising adsorbent for the effective removal of pollutants of heavy metals and dyes for environmental remediation purposes.

Structural, magnetic, and catalytic studies of microwave-combustion/ball-mill synthesized zinc ferrite nanoparticles

By utilizing the microwave-combustion approach, it was possible to synthesize nanocrystals made of zinc ferrite from their stoichiometric metal nitrates and glycine mixtures. The magnetic and structural traits were assayed via FTIR, XRD, SEM, TEM and VSM. Results demonstrated that the as-prepared sample is a monophase zinc ferrite with noticeable crystallinity and 27 nm crystallite proportions. A trace of the α-Fe2O3 phase is observable and the crystallite size diminished with milling. The SEM micrographs show that the samples have a mesoporous structure. TEM images showed agglomerated particles, while the as-prepared samples electron diffraction patterns maintained high crystallinity. The as-prepared ZnFe2O4 with a saturation magnetization value of 47 emu/g at room temperature was observed. After 330 min of milling, the aforementioned value was reduced to 29 emu/g. The catalytic activity of all samples was analyzed via dehydrogenation-dehydration of isopropyl alcohol. The outcomes showed the robust activity and high selectivity of the samples towards propene and acetone formation.

Co-precipitation of zinc ferrite nanoparticles in the presence and absence of polyvinyl alcohol with other constant parameters and the analysis of polyvinyl alcohol mediated zinc ferrite nanoparticles

In the present study, a less explored morphology controlling synthesis technique – coprecipitation was used in the synthesis of zinc ferrite nanoparticles. Zinc ferrite nanoparticles were synthesized in the presence and absence polyvinyl alcohol (PVA) mediation by maintaining the other parameters constant. The crystallite size, determined by X-ray diffraction technique was greater for PVA mediated zinc ferrite (67 nm) compared to the zinc ferrite synthesized in the absence of PVA (52 nm). The morphology of the samples was analyzed using scanning electron microscopy technique. The use of PVA as surfactant resulted in reduced agglomeration, refined morphology, smaller particle size and hence high surface to volume ratio of the zinc ferrite nanoparticles. The PVA mediated zinc ferrite was further characterized. The optical, magnetic, photocatalytic and antibacterial properties of the sample were determined. The sample had a narrow optical bandgap energy of 1.98 eV. It exhibited ferrimagnetic behaviour suggesting the formation of mixed spinel structured zinc ferrite with zinc and oxygen vacancies. Photocatalytic efficiency of the sample was determined by degrading methylene blue in the presence of sunlight and halogen lamp. The antibacterial activity of the sample was studied against Escherichia coli and Staphylococcus aureus.

Hydrothermally Synthesized Magnesium doped Zinc Ferrite Nanoparticles: An extensive study on structural, optical, magnetic, and dielectric properties

Magnesium-doped Zinc ferrite (MgxZn1-xFe2O4) nanoparticles with an average size of 10.1-5.89 nm were prepared by low-temperature hydrothermal method using NaBH4 as the reducing agent. The structural, microstructural, optical, magnetic, and dielectric properties of these nanoparticles were extensively studied. Rietveld refinement profile confirmed the formation of mixed spinel structures with cubic lattices (space group Fd3m). A complete microstructural study revealed the polycrystallinity nature of the powder along with the formation of nano-sized particles. The Raman spectral analysis showed broadening, merging, and shifting of Raman peaks with an increase in dopant concentration. The X-ray photoelectron studies exhibited the presence of Fe2+ and Fe3+ ions corroborating the results obtained from Rietveld analysis. The optical studies elucidate a reasonably high absorbance in the UV region with a bandgap of 2.05-1.92 eV, which showed a minimum value of 1.92 eV for 50% of Mg doping. These nano-sized ferrite particles were observed to be superparamagnetic due to their small size and gradually developed to a ferromagnetic state, but with a low value of magnetization, coercivity, and remanent magnetization. These nano ferrites exhibiting high dielectric constant, high impedance, and significantly low loss may have potential applications in communication devices.

Impact of calcination temperature on structural and optical properties of erbium-doped zinc ferrite nanoparticles

ABSTRACT 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.