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In this study, we investigated a comparison of the structure, morphology, optic, and magnetic (room temperature (RT)) features of Er3+ and Sm3+ codoped CoFe2O4 (CoErSm) nanospinel ferrite (NSFs) (x ≤ 0.05) synthesized via hydrothermal (H-CoErSm NSFs) and sonochemical (S-CoErSm NSFs) approaches. The formation of all products via both synthesis methods has been validated by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM), along with energy-dispersive X-ray (EDX) and transmission electron microscopy (TEM) techniques. The single phase of the spinel structure (except for the Hyd sample with x = 0.03) was evidenced by XRD analysis. The D XRD (crystallite size) values of H-CoErSm and S-CoErSm NSFs are in the 10-14.7 and 10-16 nm ranges, respectively. TEM analysis presented the cubic morphology of all products. A UV-visible percent diffuse reflectance (DR %) study was performed on all products, and E g (direct optical energy band gap) values varying in the 1.32-1.48 eV range were projected from the Tauc plots. The data of RT magnetization demonstrated that all prepared samples are ferromagnetic in nature. M-H data revealed that rising the contents of cosubstituent elements (Sm3+ and Er3+ ions) caused an increase in M s (saturation magnetization) and H c (coercive field) in comparison to pristine samples. Although concentration dependence is significant (x > 0.02), no strict regularity (roughly fluctuating) has been ruled out in M s values for doped samples prepared via the hydrothermal method. However, sonochemically prepared samples demonstrated that M s values increase with increasing x up to x = 0.04 and then decrease with the further rise in cosubstituent Sm3+ and Er3+ ions. The calculated values of M s and H c were found to be greater in H-CoErSm NSFs compared to those in S-CoErSm NSFs. The present investigation established that the distribution of cations and the variation in crystallite/particle sizes are efficient to control the intrinsic properties of all samples.
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Co-Ni ferrite is one of the crucial materials for the electronic industry. A partial substitution with a rare-earth metal brings about modification in crystal lattice and broadens knowledge in the discovery of new magnetic material. Current work reports a Ga3+ substitution in the Co-Ni ferrite with composition Co0.5Ni0.5Fe2-xGaxO4 (where x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0), herein referred to as spinel ferrite microspheres (CoNiGa-SFMCs). The samples were crystallized hydrothermally showing a hollow sphere morphology. The crystal phase, magnetic, morphology, and optical behaviour were examined using various microscopy and spectroscopic tools. While the XRD confirmed the phase of SFMCs, the crystallite size varied between 9 and 12 nm. The Tauc plot obtained from DRS (diffuse reflectance spectroscopy) shows the direct optical energy bandgap (Eg) of the products, with the pristine reading having the value of 1.41 eV Eg; the band gap increased almost linearly up to 1.62 eV along with rising the Ga3+ amount. The magnetic features, on the other hand, indicated the decrease in coercivity (Hc) as more Ga3+ is introduced. Moreover, there was a gradual increase in both saturation magnetization (Ms) and magnetic moment (nB) with increasing amount of Ga3+ till x = 0.6 and then a progressive decline with increases in the x content; this was ascribed to the spin-glass-like behavior at low temperatures. It was detected that magnetic properties correlate well with crystallite/particle size, cation distribution, and anisotropy.
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In this study, the samples of the ZnFe2O4 (ZFO) spinel ferrites nanoparticles (SFNPs), Co0.5Ni0.5Ga0.01Gd0.01Fe1.98O4 (CNGaGdFO) SFNPs and (Co0.5Ni0.5Ga0.01Gd0.01Fe1.98O4)x/(ZnFe2O4)y (x:y = 1:1, 1:2, 1:3, 2:1, 3:1 and 4:1) (CNGaGdFO)x/(ZFO)y spinel ferrite nanocomposites (NC) have been synthesized by both sol-gel and Green pulsed laser ablation in liquid (PLAL) approaches. All products were characterized by X-ray powder diffraction (XRD), scanning and transmission electron microscopies (SEM and TEM), elemental mappings and energy dispersive X-ray spectroscopy (EDX). It was objected to tune the magnetic properties of a soft spinel ferrite material with a softer one by mixing them with different fractions. Some key findings are as follows. M-H investigations revealed the exhibition of ferrimagnetic phases for all synthesized samples (except ZnFe2O4) that were synthesized by sol-gel or PLAL methods at both 300 K and 10 K. ZnFe2O4 ferrite NPs exhibits almost paramagnetic feature at 300 K and glass-like phase at very low temperatures below 19.23 K. At RT analyses, maximum saturation magnetization (MS) of 66.53 emu/g belongs to nanocomposite samples that was synthesized by sol-gel method and x:y ratio of 1:3. At 10 K analyses, MS,max = 118.71 emu/g belongs to same nanocomposite samples with ratio of 1:3. Maximum coercivities are 625 Oe belonging to CNGaGdFO and 3564 Oe belonging to NC sample that was obtained by sol-gel route having the 3:1 ratio. Squareness ratio (SQRs = Mr/MS) of NC sample (sol-gel, 4:1 ratio) is 0.371 as maximum and other samples have much lower values until a minimum of 0.121 (laser, 3:1) assign the multi-domain wall structure for all samples at 300 K. At 10 K data, just CNGaGdFO has 0.495 SQR value assigning single domain nature. The maximum values of effective crystal anisotropy constant (Keff) are 5.92 × 104 Erg/g and 2.4 × 105 Erg/g belonging to CNGaGdFO at 300 K and 10 K, respectively. Further, this sample has an internal anisotropy field Ha of 1953 Oe as largest at 300 K. At 10 K another sample (sol-gel, 3:1 ratio) has Ha,max of 11138 Oe which can also be classified as a soft magnetic material similar to other samples. Briefly, most magnetic parameters of NCs that were synthesized by sol-gel route are stronger than magnetic parameters of the NCs that were synthesized by PLAL at both temperatures. Some NC samples were observed to have stronger magnetic data as compared to magnetic parameters of Co0.5Ni0.5Ga0.01Gd0.01Fe1.98O4 NPs at 10 K.
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The effect of Er3+ and Y3+ ion-co-substituted Mn0.5Zn0.5Er x Y x Fe2-2x O4 (MZErYF) (x ≤ 0.10) spinel nanoferrites (SNFs) prepared by a sonochemical approach was investigated. Surface and phase analyses were carried out using SEM, TEM, and XRD. Hyperfine parameters were determined by fitting room-temperature (RT) Mossbauer spectra. Magnetic field-dependent magnetization data unveiled the superparamagnetic nature at RT and ferrimagnetic nature at 10 K. RT saturation magnetization (M S) and calculated magnetic moments (n B) are 34.84 emu/g and 1.47 µB, respectively, and have indirect proportionalities with increasing ion content. M S and n B data have a similar trend at 10 K including remanent magnetizations (M r). The measured coercivities (H C) are between 250 and 415 Oe. The calculated squareness ratios are in the range of 0.152-0.321 for NPs and assign the multidomain nature for NPs at 10 K. The extracted effective magnetocrystalline constants (K eff) have an order of 104 erg/g except for Mn0.5Zn0.5Er0.10Y0.10Fe1.80O4 SNFs that has 3.37 × 105 erg/g. This sample exhibits the greatest magnetic hardness with the largest magnitude of H C = 415 Oe and an internal anisotropy field H a = 1288 Oe among all magnetically soft NPs.
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In this paper, we introduced a comparative study of Sm-Tm-substituted Sr-Ba nanohexaferrites (NHFs), Sr0.5Ba0.5TmxSmxFe12-2xO19 with x = 0.00-0.05, manufactured via both citrate sol-gel auto-combustion and ultrasonication approaches. The phase formation of M-type hexaferrite (HF) for both compositions was confirmed by X-ray diffraction (XRD) powder pattern, Fourier-transform infrared (FT-IR) spectra, scanning and transmission electron microscopy (SEM and TEM) micrographs, energy dispersive X-ray (EDX) spectra, and elemental mappings. The magnetic properties at room temperature (RT) and low temperature (T = 10 K) were also investigated. M-H loops revealed ferrimagnetic nature for various prepared nanohexaferrites via sol-gel and ultrasonication routes. The Ms (saturation magnetization) and Mr (remanence) values increased with increasing Tm-Sm substituting contents. Ms and Mr reached their maximum values at x = 0.04 in the case of samples prepared using the sol-gel technique and at x = 0.03 for those prepared via ultrasonication route. M-H loops were very broad in samples prepared via ultrasonication route in comparison to those produced by means of the sol-gel approach, implying that the products synthesized via ultrasonication route have greater values of coercivity (Hc). The variations in Hc values with respect to Tm-Sm substitutions were governed by the evolutions in the magneto-crystalline anisotropy. Diffuse reflectance spectra (DRS) were employed to estimate the direct band gap of pristine and co-substituted Sr0.5Ba0.5Fe12O19 hexaferrites. Optical energy band gaps (Eg) of pristine samples were significantly tuned by co-substitution of Tm3+ and Sm3+ ions. Eg values of the Sr0.5Ba0.5Fe12O19 sample, which was synthesized using the sol-gel method, decreased almost linearly from 1.75 to 1.45 eV by increasing co-doped ion content. However, we observed a sharp drop from 1.85 eV to an average of 1.50 eV for the samples, which were synthesized using the ultrasonication approach.
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In this study, we present the synthesis and the characterization of Copper (II) chloride complex with 3-amino-1-methylbenzene (3A1MB). This complex was characterized by vibrational and EPR spectroscopic techniques and elemental analysis. The molecular structure and spectrometry of this complex: Cu(3A1MB)2Cl2 and its ligand: 3A1MB have been investigated theoretically by performing DFT/B3LYP calculations. Cu(3A1MB)2Cl2 has been optimized as two conformers and the more stable conformer is determined. The optimized geometries and calculated vibrational frequencies have been evaluated via comparison with experimental values, and the normal modes were assigned on the basis of the percent potential energy distribution (PED). A good agreement between calculated and experimental data is observed.