Manganese ferrites nanoparticles (NPs) substituted with both Co2+ and Zn2+ simultaneously (CoyZnyMn1-2yFe2O4 NPs for y=0.0 to 0.5), have been produced by hydrothermal approach. The substitution with ...both Co2+ and Zn2+ ions on the structure, spectroscopic and magneto-optical properties of nanocrystalline MnFe2O4 spinel ferrites have been analyzed in detail. The formation of spinel phase and structural changes induced by Co2+ and Zn2+ ions substitutions were confirmed by X-ray diffraction studies. Rietveld refinement revealed the cubic spinel phase for all products (minor amount of Fe2O3). Lattice constant and crystallite size were found to decrease from 8.478 to 8.370Å and from 14.68 to 8.22nm, respectively with increasing substitution of Co2+ and Zn2+ ions. HR-SEM and HR-TEM micrographs revealed the high homogeneity cubic structure of samples. The hyperfine magnetic field values for all products after Mn2+, Zn2+ and Co2+ ions substitution were determined by Mössbauer analysis. The estimated optical Eg (Energy band gap) values are in the range of 1.41–1.54eV for the samples. The smaller Eg values are mainly attributed to greater particle size and decreasing quantum confinement effect.
Nowadays, CoFe
2
O
4
(cobalt ferrite) nanoparticles have fascinated numerous researcher’s consideration because of their latent implementation in water treatment. CoFe
2
O
4
nanoparticles are ...cost-efficient magnetic materials and are stable under diverse environments. Therefore, they are effortlessly removed from purified water by means of an external magnetic field and reclaimed for quite a lot of cycles. In this analysis, the focus was given on learning the influences of some aspects including calcination temperature, crystalline size, pH, synthesis method, and dopant type on the magnetic properties of CoFe
2
O
4
nanocomposites and nanoparticles. The implementation of CoFe
2
O
4
nanoparticles in water purification and its capability to be united with various nanoparticles for adsorption and photocatalysis were entirely conferred. The chance of retrieval and reprocess of CoFe
2
O
4
nanoparticles and its nanocomposites were discussed. Finally, the holes which are still not built up for study in the modification of physical properties and further magnetic properties of CoFe
2
O
4
nanoparticles for its complete usage in water treatment were delineated. Henceforth, using CoFe
2
O
4
nanoparticles and its nanocomposites at trade scale for water treatment will definitely reduce the expenses of water as it uses visible light as the energy source and because of its capability to be recycled numerous times.
This study investigated the effect of Nb3+ substitution on the magnetic and structural properties of CoFe2O4 nanoparticles (NPs) synthesized by hydrothermal approach. The formation of a single phase ...of spinel ferrite was confirmed through X-ray powder diffraction, and crystallite sizes in the range 18–30 nm were observed. Moreover, it found that the Fourier transform infrared (FT-IR) spectra of the NPs included the main vibration bands of the spinel structure. The partially cubic structure was confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The energy band gaps for CoNbxFe2-xO4 were estimated to be in the range 0.48–0.53 eV for Nb3+ content x = 0.0–0.10. Magnetization measurements at room temperature (RT; 300 K) and at 10 K were performed on spinel CoNbxFe2-xO4 (0.00 ≤ x ≤ 0.10) NPs using a vibrating sample magnetometer (VSM). Nb3+ doping significantly changed the magnetization and coercivity of the Co ferrite samples. RT hysteresis curves indicated well-defined ferrimagnetic behavior for all prepared NPs with saturation magnetization (Ms) in the range 44.45 – 49.40 emu/g and remanent magnetization (Mr) in the range 12.16 – 17.90 emu/g. The coercive field (Hc) is found to be equal 936 Oe and is decreased with Nb3+ substitutions. However, hysteresis curves at 10 K showed finite remanent specific magnetization (1.90–6.70 emu/g) but significant asymmetric coercivity (715–2810 Oe), particularly for the Nb3+-doped samples. At 10 K, the magnetization values were 4–6 times smaller but symmetric coercivity field values were 2–3 times larger compared with the RT-VSM curves. The obtained magnetic parameters indicated the semi-hard magnetic character of the Co ferrite samples at low temperatures.
Display omitted
Tm–Tb co-substituted Sr–Ba hexaferrite (HFs), Sr0.5Ba0.5TmxTbxFe12-2xO19 (x = 0.00–0.05), were produced by ultrasonic assisted citrate sol-gel approach. The compositions were characterized using ...diverse characterization techniques including X-rays diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning and transmission electron microscopes (SEM and TEM), diffuse reflectance spectroscopy (DRS), and physical property measurement system with vibrating sample magnetometer head (PPMS-VSM). All products are pure and consist of only hexaferrite phase except x = 0.05 composition, which contains minor impurity Fe2O3 phase. Co-doping of Tm3+ and Tb3+ ions increases the 1.73 eV band gap of Sr0.5Ba0.5Fe12O19 to maximum value of 2.65 eV belonging Sr0.5Ba0.5Tm0.03Tb0.03Fe11.94O19 HF. The magnetic properties were investigated at 300 K (RT) and 10 K. Magnetization measurements indicated ferrimagnetic behaviors for different prepared hexaferrites. It was noticed that the Ms (saturation magnetization) and Mr (remanence) grew with rising Tb–Tm co-substitution proportion up to x = 0.03 and then started decreasing. The intensification in the Ms and Mr values up to x = 0.03 was mainly ascribed to the magnetic moments of Tb3+ ions (9.7 μB) and Tm3+ ions (7.5 μB) that are superior than that of Fe3+ ions (5 μB) and to strengthening of exchange coupling among Fe sites. At higher co-substitution contents, the formation of impurity phase resulted in reducing the magnetization. The coercivity is larger for lower Tb–Tm co-substitution level compared to non-substituted one and reduced for highest level. It was revealed that the coercivity is mainly dominated by the magneto-crystalline anisotropy in different prepared hexaferrites. The examination of M-T curves showed ferrimagnetic behavior in the whole temperature range of 325 down to 10K and the existence of super-spin glass-like behavior at very low temperatures.
The structure, morphology, optical and magnetic properties of Sr0.5Ba0.5TmxTbxFe12-2xO19 (x = 0.00–0.05) hexaferrites produced via ultrasonic assisted citrate sol-gel approach were investigated. Tb–Tm substitution effect could enhance the magnetic properties of SrBa hexaferrites. Display omitted
•Sr0.5Ba0.5TmxTbxFe12-2xO19 (x = 0.00–0.05) hexaferrites were produced by ultrasonic assisted citrate sol-gel approach.•All products are pure except x = 0.05 composition that contains minor Fe2O3 phase.•Optical band gap energy increased with increasing x up to 0.03 and then decreased.•The produced hexaferrites exhibit ferrimagnetic behavior at both 300 and 10 K.•Lower Tb–Tm substituting contents (x ≤ 0.03) improved the values of Ms, Mr and Hc.
•Single-phase Ni0.3Cu0.3Zn0.4TmxFe2−xO4 (0.0 ≤ x ≤ 0.10) nanospinel ferrites were synthesized via sonochemcial approach.•The optical band gap energy Eg increased with the increase in Tm3+ ...content.•Magnetic properties revealed superparamagnetic property at room temperature and soft ferromagnetic nature at 10 K.•Tm3+ substitutions significantly affect the magnetizations data of NiCuZn nanoferrite.•A decreasing trend in the Ms, Hc, Mr, and nB values was detected with Tm3+ substitution.
In this study, Tm3+ ion substituted NiCuZn nanospinel ferrites, Ni0.3Cu0.3Zn0.4TmxFe2−xO4 (0.0 ≤ x ≤ 0.10), have been synthesized sonochemically. The structural, spectroscopic, morphological, optic and magnetic investigation of the samples were done by X-ray powder diffractometry (XRD), Fourier transform infrared spectrophotometry (FT-IR), UV–Vis diffused reflectance (%DR) spectrophotometry, transmission and scanning electron microscopies (TEM and SEM) along with EDX, Vibrating sample magnetometry (VSM), respectively. The purity of prepared products were confirmed via XRD, FT-IR, EDX and elemental mapping analyses. The analyses of magnetization versus M(H) (applied magnetic field) were performed at 300 and 10 K. The following magnetic parameters like Ms (saturation magnetization), SQR = Mr/Ms (squareness ratio), nB(magnetic moment), Hc (coercivity) and Mr (remanence) have been discussed. M(H) loops revealed superparamagnetic property at RT and soft ferromagnetic nature at 10 K. It is showed that the Tm3+ substitutions significantly affect the magnetizations data. A decreasing trend in the Ms, Hc, Mr, and nB values was detected with Tm3+ substitution.
Ionizing radiation (I
on
R) such as beta and alpha, positrons, X-rays, and gamma rays cause harmful effects on living organisms, especially humans, and they represent a fundamental problem in the ...modern age. I
on
R-protecting materials are compulsory to avert this problem. Hence, the development of good performant I
on
R shields has gained huge interest. In this work, we investigated the radiation shielding peculiarities of Pb-free barium titanium (BT) added with different amounts of M-type hexaferrite (MH). The impact of MH inclusion on the phase, structural, and shielding capacity of BT sample was systematically investigated. PXRD analysis showed that all BT phases crystallized into a cubic structure. SEM images along with elemental mapping revealed the successful formation of (BT-MH) composites. The radiation shielding peculiarities were measured using HPGe detector and three radioactive sources (Co-60, Cs-137, and Am-241). It was found that at 0.6617, 1.173, and 1.333 MeV, the ceramics with higher MH content have higher mass attenuation coefficient values. The MAC values reduce when the energy increases, which indicates that the ceramics have better shielding capabilities against low energy photons. The half value layer results showed that by adding more MH into the ceramic system, more photons are attenuated at that energy, meaning a thinner shield is needed to attenuate half of the incoming photons. We evaluated the radiation shielding efficiency (RSE) and we found that at energy of 0.05954 MeV, BT-MH2 has the highest RSE of 99.836%.
The combination of two or more nanoparticles found to be effective strategy to synthesize nanocomposites for better drug delivery and treatment. In the present study, we have combined cobalt (Co), ...nickel (Ni), niobium (Nb), and iron oxide (Fe
2
O
4
) and prepared niobium substituted cobalt-nickel nano-ferrite nanocomposites (Co
0.5
Ni
0.5
Nb
x
Fe
2-x
O
4
(x ≤ 0.1) by using hydrothermal approach. We have characterized the structure and morphology of nanocomposites by using XRD, EDX, TEM and SEM methodologies. We have examined the impact of nanocomposites (Co
0.5
Ni
0.5
Nb
x
Fe
2-x
O
4
(x ≤ 0.1) on cancerous cells (human colorectal carcinoma cells, HCT-116) by using MTT assay. We have also checked the impact of nanocomposites on normal and non-cancerous cells (human embryonic kidney cells, HEK-293) to confirm the specificity of their actions. Post- 48 h treatment of Co
0.5
Ni
0.5
Nb
x
Fe
2-x
O
4
(x ≤ 0.1) led to dose-dependent inhibition of cancer cells growth and proliferation. However, no cytotoxic effect was observed on the normal cells (HEK-293). In addition, DAPI stained nuclear DNA staining analysis demonstrates that the Co
0.5
Ni
0.5
Nb
x
Fe
2-x
O
4
(x ≤ 0.1) treatment also caused nuclear DNA disintegration which is the marker for programmed cell death. These results demonstrate that synthesized nanocomposites Co
0.5
Ni
0.5
Nb
x
Fe
2-x
O
4
(x ≤ 0.1) selectively target the colon cancer cells and induce cancer cell death.
Communicated by Ramaswamy H. Sarma
•Zr substituted Sr hexaferrites were prepared without any impurity by sol-gel auto-combustion method.•Optical band gap energy decreased with increasing Zr content.•Zr substituted Sr-hexaferrites ...exhibit ferrimagnetic nature.•Values of Ms, Mr, and nB decreased with increasing Zr substitution content.
Hexaferrite (HFs) of Sr1−xZrxFe12O19 (0.00 ≤ x ≤ 0.10) have been produced through Citrate Sol-gel approach. The characteristic of compositions is studied through XRD (X-ray powder diffractometer), SEM (Scanning electron microscopy), EDX (Energy-dispersive X-ray), TEM (Transmission electron microscopy), DR% (UV–Visible diffuse reflectance spectrophotometer), FT-IR (Fourier transform infrared spectrophotometer). The single-phase Sr hexaferrite was confirmed for each product by XRD. The crystallites size of the products was calculated as 22–40 nm range which makes this material as an appropriate candidate for high density recording media. The optical band gap tends to decrease when increasing the Zr content. The analyses of magnetization versus applied magnetic field, M(H), were performed at room (300 K; RT) and low (10 K) temperatures. The various magnetic parameters including coercivity Hc, squareness ratio (SQR = Mr/Ms), remanence Mr, saturation magnetization Ms and magnetic moment nB were deduced and described in detail. At both considered temperatures, the M(H) results showed ferrimagnetic nature. It is showed that the Zr substitutions significantly affect the magnetizations data. A significant decrease in the Ms, Mr, and nB was observed with Zr substitution.
Vanadium substituted nickel ferrite nanoparticles (NPs), NiFe
2−x
V
x
O
4
(0.0 ≤ x ≤ 0.3) were prepared by sol–gel approach. The influence of calcination on the magnetic and optical properties of ...NiFe
2−x
V
x
O
4
(0.0 ≤ x ≤ 0.3) NPs were investigated deeply. The lattice parameters ‘a’ are almost constant with V-substitution for as-prepared and calcined samples. It was found that the calcination process both increased the crystallites size and removed the impurity phases in all products. The values of optical energy band gap, E
g
, are in range of 1.38–1.69 eV and 1.39–1.56 eV for as-prepared and calcined samples, respectively. The specific magnetic parameters such as saturation magnetization M
s
, remanence M
r
, coercivity H
c
, squareness ratio (SQR) and magnetic moment
n
B
were determined from magnetization versus applied field measurements. The various M(H) curves exhibit ferromagnetic behavior at room temperature and 10 K. A decrease in M
s
, M
r
and
n
B
values was observed with Vanadium substitution. However, an increase in H
c
value was observed. The obtained magnetic results are primarily resulted from the substitution of Fe ions with V ions that will weaken the A–B super-exchange interactions. Besides, the calcination step leads to an improvement in the various M
s
, M
r
and
n
B
parameters. This enhancement is due to the enlargement of crystallites size (or grains size) and the strengthening of the A–B exchange interactions caused by the calcination effect. Nevertheless, the enlargement in the crystallites size is followed by a reduction in H
c
values.
BaM hexaferrites substituted with both Ca
2+
and Mg
2+
ions, namely, Ba
1-2×
Ca
x
Mg
x
Fe
12
O
19
(0.0 ≤ x ≤ 0.1), synthesized during a sol–gel auto-combustion route. The hexaferrite phase and ...morphology of all samples were investigated using X-ray powder diffraction, a field emission scanning electron microscope, a high-resolution transmission microscope, and Fourier transform infrared spectroscopy. In addition, an M-type hexagonal structure was confirmed using XRD for all samples. FE-SEM and TEM revealed the shape of the hexagonal plate. Measurements of the magnetization versus the field M(H) of Ba
1-2×
Ca
x
Mg
x
Fe
12
O
19
(0.0 ≤ x ≤ 0.1) nanohexaferrites were conducted at 300 and 10 K. A hard-ferrimagnetic behavior at both 300 and 10 K was noted for the different products produced. The squareness ratio indicates the uniaxial anisotropy for various products. The deduced values of saturation magnetization (
M
s
) in all substituted samples are higher than in the pristine sample (
x
= 0). The Ba
0.96
Ca
0.02
Mg
0.02
Fe
12
O
19
nanosized hexaferrite showed the highest values of
M
s
, remanence
M
r
, magneton number (
n
B
), and magnetocrystalline anisotropy constant (
K
eff
). In contrast, the values of the coercive field (H
c
) and intrinsic coercivity (H
ci
) diminish with the increase in the amount of the substituted Ca and Mg elements.
Highlights
Nanosized Ba
1-2×
Ca
x
Mg
x
Fe
12
O
19
nanohexaferrites have been synthesized via sol–gel auto-combustion method.
XRD patterns showed a hexagonal structure with pure single phase.
Ba
1-2×
Ca
x
Mg
x
Fe
12
O
19
nanohexaferrites exhibit hard-ferrimagnetic behavior.
The saturation magnetization (
M
s
) and remanence (
M
r
) enhanced with Ca and Mg substitutions in BaM haxaferrites.
The coercive fields (H
c
) decrease with Ca and Mg concentrations.
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