Formation Of Ferrite Phase Research Articles

The structural, magnetic and electrical properties of chromium doped calcium ferrite nanoparticles

Calcium ferrite nanoparticles doped with Chromium (10-50 mol %) are synthesized using the solution combustion method, employing citrus Lemon extract as a reducing agent, followed by a calcination process at 500oC. Various characterization techniques are employed on the calcined samples. The Bragg reflections resulting from Chromium doping confirm the formation of a singular orthorhombic calcium ferrite phase. Crystallite sizes determined using both Scherrer’s and W-H plot methods found to be decreases with increase in dopant concentration. The surface morphology showcases agglomerated nanoparticles with irregular shapes and sizes, accompanied by pores and voids. The energy band gap found to be increases with increase in dopant concentration from 2.82 to 2.93 eV. The hysteresis loop analysis provides magnetic parameters including saturation magnetization (Ms), remanence (Mr), and coercivity (Hc). As the dopant concentration increases, Ms and Hc found to be maximum at 30 mol% cr3+ concentration in CaFe2O4 NPs. Linear increase in frequency-dependent conductivity at lower frequencies was observed. The presence of semicircles at low frequencies signifies compliance with the Cole-Cole formula for impedance behavior. Additionally, a detailed discussion on dielectric properties is presented. Notably, the dielectric constant decreases from 4.2 to 2.74 with an increase in dopant concentration. These distinctive attributes position the samples as suitable candidates for memory devices as well as high-frequency device applications.

Electrical transport and dielectric relaxation mechanism in Zn0.5Cd0.5Fe2O4 spinel ferrite: A temperature- and frequency-dependent complex impedance study

In the present study, the frequency-dependent dielectric relaxation and electrical conduction mechanisms in sol-gel-derived Zn0.5Cd0.5Fe2O4 (ZCFO) spinel ferrite were studied in the temperature range of 343–438 K. The formation of the ZCFO spinel ferrite phase with space group Fd3m was confirmed by X-ray diffraction analysis. The dielectric relaxation and electrical conduction mechanisms were studied using complex impedance spectroscopy (CIS). In the Nyquist plots, depressed semicircles were fitted with an equivalent circuit model with configuration (RGBQGB) (RGQG), signifying the contributions from grain boundaries and grains to the charge transport mechanism in the sample. The frequency-dependent AC conductivity was found to follow Jonscher's power law, and the frequency exponent term depicted the overlapping large polaron hopping (OLPH) model as the dominant transport mechanism. The activation energies for conductivity, electric modulus and impedance were calculated to identify the nature of the charge carriers governing the relaxation and conduction mechanisms in the prepared sample. Complex modulus studies confirmed the non-Debye type of dielectric relaxation, whereas tangent loss and dielectric constant analyses confirmed the thermally activated hopping mechanism of charge carriers in Zn0.5Cd0.5Fe2O4 spinel ferrite.

A Study on Fine-Tuning the Optical Energy Band Gap and Various Optical Parameters with the Impact of Gadolinium Composition in NGFO Ferrite Nanoparticles

In the present work, gadolinium-doped nickel ferrite nanoparticles with the chemical composition NiFe2−xGdxO4 (X = 0.00, 0.05, 0.10, 0.15, 0.20, and 0.25) have been prepared by the sol-gel auto-combustion method and calcinated at 700 ∘C. The spinel ferrite phase formation was confirmed with the XRD graphs. In all the samples, the typical absorbance peak was observed in between 250–300 nm. Tauc plots were used to calculate the optical energy band gap, found in the range of 4.033–4.144 eV, and it was also calculated using x-ray density to be in the range of 3.690–4.300 eV. Both of them were observed in good agreement with each other, and we conclude that the Gd composition could finely tune the optical energy band gap. The impact of Gd composition was clearly observed on optical parameters. The refractive index, reflectivity, absorption coefficient, optical dielectric constant, and dielectric susceptibility have shown the increasing tendency from 2.1140 to 2.2325, 12.80 to 14.53%, 5.4380 to 6.3032 cm−1, 3.4690 to 3.9840 and 0.2760 to 0.3170, respectively, whereas the transmission coefficient decreased from 0.7730 to 0.7461.

Influence of synthesis route on structural properties of SnFe2O4 spinel phase via methods of co-precipitation, sol–gel and solvothermal: morphology, phase analysis, crystallite size and lattice strain

In this study, regarding to the wide applications of spinel ferrites in various fields such as Li ion-batteries, photocatalysts, and optoelectronics, the structural and morphological properties of tin ferrite oxide (SnFe2O4) nanoparticles are investigated using X-ray diffraction (XRD) analysis and field emission scanning electron microscopy (FESEM). The sol–gel, solvothermal, and co-precipitation methods were used to synthesize the SnFe2O4 nanoparticles, and the effect of annealing temperatures at T = 350 °C, 450 °C, and 550 °C was investigated. The XRD results confirmed the formation of tin ferrite spinel phase at an annealing temperature of 350 °C with a preferred peak (311). Crystallite size (D) and strain (ε) of SnFe2O4 nanoparticles was determined in region 20–45 nm and 2–4 × 10–4, respectively, using the Scherer, Williamson–Hall, and Rietveld computational methods. The results showed that the crystallite size in the samples increased with increasing annealing temperature. This increase is attributed to the reduction of defects, imperfections and lattice strain, which leading to an increase in the lattice constants and unit cell volume in the nanocrystalline structure. The Rietveld method determine smaller crystal sizes compared to the Williamson–Hall and Scherer methods because it can correct for peak broadening by taking into account all instrumental factors. The FESEM images of the synthesized nanostructures of SnFe2O4 showed cubic and polyhedral grains with cluster growth and an average grain size of 50–80 nm. According to the crystal structure of tin ferrite spinel, the cubic morphology confirmed the formation of this structure. The average crystallite size and grains in the synthesized samples was determined using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) analysis, respectively. The formation conditions of the SnFe2O4 spinel phase and other phases in the synthesis process at different temperatures and dependence of structural parameters was studied by various structural models for the samples.

An experimental and numerical study on the influence of interlayer time interval in wire-arc additive manufacturing process

Wire arc additive manufacturing is the derivative of the metal AM process based on arc welding and a preferred technology for manufacturing large metallic components with medium to low complexity. The major problem with the WAAM process arises due to severe heat accumulation within the built structure and repeated heating-cooling cycles during layer-by-layer material deposition. Therefore, the interlayer time interval influences the microstructure and mechanical properties of the components. This paper has characterized the impact of interlayer cooling time on the microstructure and mechanical properties of SS-316L build. The local thermal cycle causes a non-uniform cooling rate, which alters the structure of the grains. The grain size decreases with increased interlayer time interval due to a faster cooling rate brought on by the low inter-pass temperature. A wider and smaller wall was deposited with less time interval. X-ray diffraction analysis confirms the formation of austenite and ferrite phases in all WAAM components with a slight difference in intensity. The wall constructed with a maximum time interval has a maximum value of average Vickers micro-hardness 244.00 HV0.5 and possesses the least coefficient of friction due to its improved property by the formation of fine grains. The maximum volume of materials was worn out from the wall deposited with lesser cooling time. The designed numerical model predicts the peak temperature and heat accumulation within the built structure which further relates to the morphological and mechanical properties of printed parts.

Modulation effect of Zr-Sm co-doped on microwave absorption performance of barium ferrite

Zr-Sm co-doped barium ferrites BaFe12–2x(ZrSm)xO19(x = 0, 0.2, 0.4, 0.6) were successfully prepared by sol-gel method. The effects of Zr-Sm co-doped on phase formation, microscopic morphology, magnetic parameters, electromagnetic and microwave absorption properties of barium ferrite were studied. The results show that the saturation magnetization(Ms) of BaFe12–2x(ZrSm)xO19 first increases and then decreases, the coercivity(Hc) first decreases and then increases with the increase of doping amount(x) of Zr-Sm. Large grain size and sheet morphology lead to the transition of BaFe11.6(ZrSm)0.2O19 towards soft magnetic properties. The introduction of Zr-Sm increases the amount of oxygen vacancies, and dielectric loss value of material is obviously enhanced, this improves the polarization relaxation of materials. At the same time, multiple natural resonance peaks appeared in the virtual part of the permeability (μ"), which regulated the absorbing properties of samples. The best microwave absorption properties of sample is obtained when doping x = 0.2, at the thickness of 2.8 mm, the maximum reflection loss(RL) is − 51.75 dB. The effective absorption bandwidth (RL ≤ −10 dB) is 4.4 GHz, it covers almost all the X-band(8–12 GHz). Compared with existing doped barium ferrite, the material possesses a greater reflection loss and excellent prospects in the field of microwave absorption.

The impacts of post‐processing treatments done under reactive and non‐reactive atmospheres on the densification of binder jetting parts

AbstractAt the intersection between chemical and materials engineering, binder jetting is an additive manufacturing technique that foregoes many of the limitations of the conventional metal 3D printing technique. Binder composition and thermal post‐processing influence final part quality. Herein, three different atmospheres, ranging from reactive (air) to non‐reactive (vacuum, argon), are studied to determine their effect on the quality of binder jetting printed parts after thermal treatments, namely debinding and sintering. These parts were printed using SS316L powder. Samples debound in air were negatively affected as they presented high porosities and low densities, averaging 6.80 (±0.4) g/cm3, whereas samples debound and sintered under vacuum demonstrated the best outcome with low porosities and high densities, averaging 7.65 (±0.1) g/cm3. This study highlights how oxide formation during debinding causes ferrite phase formation during sintering and how it affects atomic diffusion in the samples during both thermal treatments. This research also demonstrates the respective effects of these on the densification and porosity of parts.

Optimization of visible photoluminescence emission from Ni-Zn ferrite thin films

Ni-Zn ferrite films with different thicknesses were prepared by the spray method, aiming to study the relationship between the annealing effect in an oxygen rich environment and the structural, optical properties and photoluminescence emission. X-ray diffraction (XRD) analysis used with Rietveld refinement showed that all prepared samples had a single spinel phase structure. Likewise, the Fourier transform infrared (FTIR) spectra confirmed the phase formation of Ni-Zn ferrites by appearing in both of the two characteristic absorption bands which are related to the tetrahedral and octahedral sites. For annealed thin film samples of Ni-Zn ferrite, the atomic force microscope (AFM) surface morphology exhibits pinning structure on the surface in nanoscale height, whereas for un-annealed samples, there are hills and valleys cover a broad region. The different electronic transitions were estimated from the UV-visible transmission spectrum. Strong photoluminescence (PL) intensity in the visible range was observed under the excitation of UV radiation. The intensity of the PL signal was strongest at a film thickness of 750 nm then decreased for higher thicknesses. This could be interpreted by using proposed energy level structures based on the transmission spectrum of the investigated samples. The strong PL intensity introduces the samples as a direct optical detector for UV radiation.

Influence of Pr-ion substitution in Cu2X hexaferrites on their magnetic and dielectric properties

A series of Sr2Cu2PrxFe28-xO46 (x = 0.00 to x = 0.32 with a step of 0.08) hexagonal ferrite was synthesized by the heat treatment method, and heated at 1300 °C for 6 h. These samples were characterized using FTIR, XRD, FESEM, VSM, and low-frequency (20 Hz–2 MHz) dielectric measurements. FTIR investigation confirms the ferrite phase formation in all the samples. XRD investigation reveals that all samples possess the X-type as a major phase with a minor M-phase. FESEM images show smaller grain size ranges between 25.27 μm and 51.25 μm. EDX elemental analysis confirms the existence of constituent elements in synthesized materials. VSM analysis shows that prepared ferrites possess a soft magnetic nature, the saturation magnetization of heated samples was found in the range of 35.99 Am2/kg to 49.44 Am2/kg, and coercivity was observed in the range of 10.372 kA/m to 37.443 kA/m. Relaxation peaks have been observed in the loss tangent profile for x = 0.00, 0.08. The Nyquist plot for samples S1 and S2 represents the low-loss universal capacitance circuit, while samples S3 to S5 represent the parallel conductance-capacitance circuit.

Investigation of Structural, Dielectric and Optical Properties of Polyaniline-Magnesium Ferrite Composites.

A study on the influence of magnesium ferrite nanoparticles on the optical and dielectric attributes of Polyaniline has been conducted. Magnesium nano Ferrite powder is synthesized by the self-propagating solution combustion method. Polyaniline-Magnesium nano ferrite composites are synthesized by chemical oxidative polymerization of aniline with the addition of Magnesium nanoparticles. The samples are characterized with XRD and UV-Vis spectrometer, in the wavelength range of 200-800 nm and studied for optical properties. Dielectric properties are studied in the frequency range of 50 Hz to 5 MHz. X-ray diffraction reveals single phase formation of Magnesium ferrite, whereas Polyaniline shows an amorphous nature. In the XRD of the composites, we see the crystalline peaks of ferrite becoming more intense with the addition of ferrite and whereas the peak of Polyaniline diminishes. The crystallite size is quantified with the Debye-Scherrer formula, and it increases as the content of ferrite in the composites increases. The micro-strain decreases in the composites as the percentage of ferrite enhances in the composites. In the UV-Vis absorption spectra of composites, the peaks of Polyaniline shift to higher wavelength and there is also an absorption band in the spectra of composites corresponding to that of Magnesium ferrite particles. Both direct and indirect band gaps are calculated with the Tauc plot, and both the optical band gap decrease as the percentage of ferrite increases in the composite. The dielectric loss and dielectric constant both decrease with frequency in all the samples, and the dielectric response are in good agreement with Maxwell-Wagner model. Ferrite-polymer composites with both conducting and magnetic properties are considered useful for electromagnetic shielding and microwave absorption.

Structural Interpretation of Sintering Temperature Effect on Optical and Electrical Properties of Pr3+‐Substituted Nickel Ferrites

Herein, the sintering temperature effect on various properties of Pr3+‐substituted nickel ferrites prepared through the sol–gel–citrate autocombustion method is presented. The Rietveld refinement of X‐ray diffraction patterns confirms the formation of the inverse spinel nickel ferrite phase with an additional orthorhombic phase PrFeO3. The crystallinity of those samples is better with a lesser weight percentage of the secondary phase for higher sintered samples. Structural parameters like crystallite size, lattice parameter, microstrain, and bond lengths depend strongly on sintering temperature with an increasing trend. Scanning electron micrographs clearly show the grain growth of the samples with sintering temperature with the formation of a secondary phase at the grain boundaries. The photoluminescence study points to the photocatalytic nature of the compositions. The bandgaps of the samples are calculated using a UV–vis study, which shows an initial decrease in values with increasing sintering temperature. The electrical study confirms the grain and grain boundary contribution to the total conductivity. With higher sintering temperatures, activation energies decrease, but the dielectric loss and saturation dielectric constant tend to increase. The scaling of conductivity and dielectric loss spectra confirm the time–temperature superposition principle.

Structural, Optical, and Dielectric Properties of CuO/CdFe2O4 Nanocomposites Synthesized by the Co-precipitation Method

Abstract In this study, xCuO/(1−x)CdFe2O4 nanocomposites (NCs) were prepared with different weight percentages (x = 0.0, 0.1, 0.3, 0.5, and 1.0) using the co-precipitation method. X-ray powder diffraction patterns revealed the formation of copper oxide (CuO) and cadmium ferrite (CdFe2O4) phases in each NC with hematite as a secondary phase. Transmission electron microscope study confirmed the existence of CuO and CdFe2O4 crystal grains with sizes of 17.86 and 18.45 nm, respectively. Optical analysis indicated that the addition of CuO caused variations in bandgap energy and shifts in the emission wavelength of the NCs. Dielectric measurements were carried out in the frequency range of 1 kHz–5 MHz, and dielectric study was performed by analyzing the frequency, temperature, and composition dependence of the dielectric parameters for the samples. Dielectric results showed the dispersion behavior of the NCs with increasing frequency and composition concentration corresponding to low dielectric losses, which makes them suitable for optoelectronics and high-frequency devices.

Microstructure and magnetization study of Li and Li–Zn ferrites synthesized by an electron beam

Lithium ferrites are widely used in high frequency electronic devices. The present work reports structural and magnetization analysis of lithium (Li0.5Fe2.5O4) and lithium-zinc (Li0.4Fe2.4Zn0.2O4) ferrites synthesized by electron beam heating (RT) of powdered and compacted samples. The synthesis was carried out at 600 and 750 °C for up to 120 min using 2.4 MeV electron beam generated by an ILU-6 pulsed electron accelerator. The characteristics of the samples synthesized by RT were compared with the ones of samples obtained by traditional thermal heating under the same temperature and time conditions. From XRD and thermomagnetometric analyses, α-Li0.5Fe2.5O4 ordered spinel phase and Li0.5(1−x)Fe2.5−0.5xZnxO4 ferrite phase with different zinc substitution were formed from Fe2O3/Li2CO3 and Fe2O3/Li2CO3/ZnO reagents, respectively. RT synthesis significantly increases the rate of interaction between the initial powders and, as a consequence, the rate of ferrite phase formation. In this case, lithium-containing ferrites can be successfully achieved from compacted powders at 750 °C, which is lower than the temperature of synthesis in conventional thermal heating. The average crystallite sizes calculated from the XRD and BET analyses were 114 nm for Li, 120 nm for Li–Zn ferrites and 142 for Li, 150 nm for Li–Zn, respectively. The specific saturation magnetization and Curie temperature were estimated and are 60 emu/g for Li, 70 emu/g for Li–Zn ferrites and 632 °C for Li, 492 °C for Li–Zn ferrites, respectively. The data obtained in this work are of considerable interest for the creation of a technology for producing ferrites at low synthesis temperatures.

Microstructure and gyromagnetic properties of low-sintered LiZnTi ferrite doped with nano-LiZn and V2O5 additives

In this study, nanoparticles of LiZn ferrite (nano-LiZn, 0.0–10.0 wt. %) fabricated via the sol-gel method and V2O5 particles were added into a Li0.43Zn0.27Ti0.13Fe2.17O4 (LiZnTi) ferrite to realize low temperature sintering. The effects of the nano-LiZn ferrite addition on the crystalline phase formation, microstructure, and magnetic properties of LiZnTi ferrite were systematically investigated. X-ray diffraction results reveal that the LiZnTi ferrite doped with nano-LiZn and V2O5 additives present a pure spinel structure, which can be explained by liquid phase of V2O5 and spinel structure of nano-LiZn, as revealed by high-resolution transmission electron microscopy and selected area electron diffraction data. Scanning electron microscopy images show that the addition of nano-LiZn leads to a change in the microstructure, with the grains becoming uniform and dense. Additionally, the variation in the saturation magnetization (Ms) depends on the LiZn content. In particular, Ms increases with increasing LiZn content from 2.0 to 10.0 wt. %. Finally, the LiZnTi ferrite doped 4.0 wt. % nano-LiZn and 0.60 wt. % V2O5 possesses a narrow ferromagnetic resonance linewidth of 197 Oe, a reduced coercivity of 192.6 A/m, and an improved bulk density of 4.73 g/cm3.

Structural,Spectral and Electrical Properties of BaNi2-xZnxFe16O27 Nanoparticles Ferrites

In the current study, w-type BNF-NPs synthesis via ceramic method.the effects of zinc ions doping on the physical properties of BNF-NPs were analyzed. The formation of BNF-NPs emphasized by XRD, FTIR, UV-Visible spectroscopy and electrical conductivity measurement. The phases structure , crysttallite size and lattice parameters wrere evaluated using XRD results. Hexagonal structure with a single phase apeares, the average grain size was found to be in Nano scale from 32 to 34 nm, while the lattice parameters increased slolly as the doping concentration of zinc ions increases. The spectra of FTIR showed main absorption bands which confirmed formation of hexagonal ferrite phase. UV-VIS analysis was also performed and found that the band gaps were in the semiconducting region and increased with increasing zinc concentration. The AC conductivity of the samples decreased with increasing zinc content and showed a dependence on the frequency and temperature. Additionally, as frequency increase the σac conductivity showed dispersion that decreased as temperature increased.dispersion decreases as the temperature increases.

Copper Ferrite nanoparticles synthesised using a novel green synthesis route: Structural development and photocatalytic activity

The copper ferrite nanoparticles, recognized for their ferromagnetic characteristics, minimal conductivity, and superior electrochemical stability, were synthesized by a facile auto combustion approach using egg white as fuel via a green synthesis route. CuFe2O4 nanoparticles' structural, morphological, and optical properties were examined. XRD is used to determine the phase formation, particle size, and lattice parameter of spinel ferrite. X-ray Diffractometer (XRD), Fourier Transform Infrared Spectrometer (FTIR), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray analysis were used to rigorously examine the phase purity of the synthesized spinel ferrite. For morphological analysis, SEM and TEM were employed, whereas EDAX was used for elemental analyses. For a better knowledge of the conduction band (CB) and valence band (VB) boundaries of the produced nanoparticles, optical experiments were conducted by UV Diffuse Reflectance Spectroscopy. The degradation of Rhodamine B dye determined the photocatalytic competence of the synthesized sample under visible light. At regular intervals of time, the entire process was observed with a spectrophotometer. CuFe2O4 nanoparticles reveal a maximum photocatalytic degradation efficiency of around 94%, which is higher than that of CuFe2O4 nanoparticles prepared via other chemical route.

A study of structural and chemical properties of Ni1-xZnxFe2O4 ferrite powder prepared by co-precipitation method

Nickel zinc nanoferrites (Ni1-xZnxFe2O4 with x ranging from 0.3 to 0.7 and 0.9) were employed in this study. Chemical co-precipitation was used to synthesize nanoparticles, X-ray diffraction, fourier transform infrared spectroscopy, field emission scanning electron microscopy analysis (FESEM), and the vibration sample magnetometer were used to determine the structure, size, morphology, and magnetic properties of nanostructures (VSM). X-ray diffraction was used to identify the crystalline phases, and all samples have cubic spinel ferrites. To evaluate particle sizes using Scherrer's formula. average crystallite sizes were in the range of (13-19)nm and FTIR spectroscopy data for respective sites were examined in the range of 200–4000 cm-1 . Between 320 and 1000 cm-1 , the formation of ferrite phase was confirmed, indicating the sample's ferrite nature. Tetrahedral complexes were assigned to the higher frequency band ν1, while octahedral complexes were assigned to the lower frequency band ν2. The M-H curve shows that Ms rises from 1.96-23.7 (emu/g).

Structural, dielectric and gas sensing properties of gadolinium (Gd3+) substituted zinc-manganese nanoferrites

Gadolinium (Gd3+) substituted zinc manganese ferrite nanoparticles with nominal compositions Zn0.7Mn0.3GdxFe2-xO4 (where x = 0.000; 0.025; 0.050; 0.075; 0.100) were successfully synthetized using co-precipitation method. The synthetized powders were calcined at 500 °C and furthermore pressed into pellets and thermally treated at 650 °C for a second time to obtain a more compact material. For the 500 ℃ thermal treated samples, X-ray analysis revealed the formation of pure spinel ferrite phase, meanwhile for the 650 ℃ thermal treated samples secondary phases appear which indicate that some of Gd3+ ions aren’t able to remain in the structure of ferrite. The morphology of samples was investigated using scanning electron microscopy (SEM) and the images show agglomerated spherical nanoparticles within 20–30 nm size range. The magnetization curves recorded in ±10 kOe range indicate a superparamagnetic behavior of the synthetized ferrite samples. At low frequencies, the Gd3+ substituted ferrite samples corresponding to x = 0.050, 0.075 and 0.100 exhibit a resonant behavior of the dielectric losses dependence, while at high frequencies the lowest value was found for the sample with x = 0.025. The introduction of Gd3+ ions in the ferrite structure leads to a non-monotonous variation of AC electrical conductivity, which decrease from 2.55 x10−6 S/m to 3 x10−7 S/m. The ferrite samples have shown a good and reproducible response to the saturated acetone vapors and the highest sensitivity value (53%) was obtained for Zn0.7Mn0.3Gd0.025Fe1.9O4 ferrite sample. The response and recovery time varies between 36 and 56 s, respectively 80–116 s and both of these are independent of Gd3+ content.

Synthesis and Characterization of Praseodymium substituted Y-type hexaferrites

Y-type Hexagonal ferrites have acquired much more attention due to their multiferroic qualities. The Standard formula for Y-type Hexagonal ferrites is given as (A2Me2Fe12O22) where A= Sr2+, Ba2+, Pb2+, La2+ and Me = Bivalent metal In Y-type hexagonal structure, two tetrahedral sites and four octahedral sites are inhabited with small cations. Multiferroic properties of Y-type hexaferrites can be affected by different factors such as synthesis methods, amount of substitution, sintering temperature and chemical composition. For the present study Praseodymium substituted strontium-based Y-type hexaferrites with chemical composition Sr2Ni2-xPrxFe12O22(where x=0.0 and 0.1) has been synthesized using sol-gel method and characterized byX-ray diffraction, Fourier Transform Infrared Spectroscopy and Impedance Analyzer. The structural analysis through XRD and FTIR verified the phase formation of Y-type ferrites having hexagonal structure. The XRD data reveals the increase in the volume, and decrease in particle size with praseodymium substitution. In FTIR, resulting peaks observed in two samples lie between 400-600 cm-1 which indicates the vibrational stretching in Fe-O bond.

Physical properties of nanosized (x)NiO/(1−x)CdFe2O4 composites

This study investigates the optical and magnetic properties of nanosized (x)NiO/(1−x)CdFe2O4 (x = 0.1, 0.2, 0.3, 0.4, 0.5, and 1) composites. The samples were synthesized using the wet coprecipitation technique. The X-ray Diffraction patterns demonstrated the formation of Nickel Oxide (NiO) and Cadmium Ferrite (CdFe2O4) phases without any chemical reaction between them. Fourier Transform Infrared results confirm the formation of pure NiO, pure CdFe2O4, and nanosized NiO/CdFe2O4 composites. Transmission Electron Microscopy micrographs show agglomeration between the nanoparticles, demonstrating the magnetic interaction between the oxide and ferrite phases. High-Resolution Transmission Electron Microscopy results verify the presence of NiO and CdFe2O4 phases in each nanosized composite without impurities, which is consistent with the XRD data. The ultraviolet–visible spectroscopy results confirmed that HCl is a better solvent than ethanol in investigating the optical properties of nanosized oxide/ferrite composites. Photoluminescence spectra exhibited asymmetricity owing to the presence of various emission peaks, which reveals the distribution of defect states within the bandgap of the nanosized composites. The Mössbauer spectra of the nanosized composites comprised an asymmetrical doublet at 300 K and an asymmetrical centered doublet within minor sextets at 77 K. Vibrating Sample Magnetometer study showed a shift at 77 K, which can be attributed to the spontaneous exchange bias effect. The magnetic parameters extracted from the M − H loops of all the synthesized nanosized composites at 77 K are higher than those at 300 K.