Metallic nanoparticles (NPs) possess unique properties which makes them attractive candidates for various applications especially in field of experimental medicine and drug delivery. Many approaches ...were developed to synthesize divers and customized metallic NPs that can be useful in many areas such as, experimental medicine, drug design, drug delivery, electrical and electronic engineering, electrochemical sensors, and biochemical sensors. Among different metallic nanoparticles, manganese (Mn) NPs are the most prominent materials, in the present study, we have synthetized unique Mn0.5Zn0.5DyxEuxFe1.8-2xO4 NPs by using ultrasonication method (x ≤ 0.1). The structure, and surface morphology of Mn0.5Zn0.5DyxEuxFe1.8-2xO4 NPs was characterized by XRD, SEM, TEM and EDX methods. We have examined the biological effects of Mn0.5Zn0.5DyxEuxFe1.8-2xO4 NPs on both normal (HEK-293) and cancerous (HCT-116) cells. We have found that the treatment of Mn0.5Zn0.5DyxEuxFe1.8-2xO4 NPs post 48 h, showed significant decline in cancer cells population as revealed by MTT assay. The IC50 value of Mn0.5Zn0.5DyxEuxFe1.8-2xO4 NPs was ranged between (2.35 μg/mL to 2.33 μg/mL). To check the specificity of the actions, we found that the treatment of Mn0.5Zn0.5DyxEuxFe1.8-2xO4 NPs did not produce any effects on the normal cells, which suggest that Mn0.5Zn0.5DyxEuxFe1.8-2xO4 NPs selectively targeted the cancerous cells. The anti-bacterial properties of Mn0.5Zn0.5DyxEuxFe1.8-2xO4 NPs were also evaluated by MIC and MBC assays. We suggest that Mn0.5Zn0.5DyxEuxFe1.8-2xO4 NPs produced by sonochemical method possess potential anti-cancer and anti-bacterial capabilities.
•Synthesis of Mn0.5Zn0.5EuxDyxFe1.8-2xO4 NPs by sonochemical method•NPs showed cytotoxic effects on colon & breast cancer cells.•NPs showed selective targeting of cancerous cells.•The IC50 value of NPs was ranged between 2.35 μg/mL and 2.33 μg/mL.•NPs also showed anti-bacterial activities.
Mn0.5Zn0.5(EuxNdxFe2-2x)O4 ferrite nanoparticles (FNP) were obtained by ultrasonic (USM) and sol-gel (SGM) methods. It was observed that SGM allows us to produce nanoparticles with the average ...crystal size of 10–40 nm and the specific surface area of 5–7.5 × 104 m2/g with a strong correlation between the chemical composition (x) and the crystal size distribution. At the same time using USM, we obtained nanoparticles with the average crystal size of 3–15 nm and the specific surface area of 1.5–1.7 × 105 m2/g without a strong correlation between Eu/Nd concentration and the crystal size distribution. The specific surface area and average crystal size are the main factors determining the antiproliferative activity of FNP. The anti-cancer activity of FNP was investigated both on cancerous cells, human adenocarcinoma cells and human colorectal carcinoma cells. It was established that samples obtained using USM were more effective in producing cytotoxic effects on cancer cells. Thus, we confirm a strong correlation between the main microstructure parameters for Mn0.5Zn0.5(EuxNdxFe2-2x)O4 ferrite nanoparticles.
Terbium (Tb) and Thulium (Tm) co-doped strontium hexaferrites (SHFs), with composition SrFe12-2xTbxTmxO19 (0.00 ≤ x ≤ 0.04), were prepared via sol-gel auto-combustion method. The effect of Tb3+ and ...Tm3+ (as co-dopants) on SHFs were investigated in detail. XRD pattern of the prepared SHFs revealed the formation of M-type SHFs. A secondary phase of Fe2O3 starts to appear for x ≥ 0.02. The optical band gaps (Eg) of the prepared SHFs were widened with the increase in doping levels. Mössbauer study showed that the Tm3+ and Tb3+ ions have the preference to occupy 12k and 2a octahedral sites. M(H) measurements were recorded at room temperature (RT; T = 300 K) and low temperature (T = 10 K). The hysteresis loops of various SHFs revealed their ferrimagnetic (FM) nature at both RT and 10 K. Magnetic parameters including saturation magnetization (Ms), remanence (Mr), coercivity (Hc), squareness ratio (SQR = Mr/Ms) and magnetic moment (nB) were determined. Compared to the pristine (undoped) sample, lower content of Tm3+ and Tb3+ co-substitution (x = 0.01) improves significantly the magnetic properties of SHFs. With further increasing co-substitution contents (x > 0.01), an impurity phase appears and as a result the magnetization reduces. The observed SQR values of the proposed SHFs above 0.5 clearly indicated their single domain character with uniaxial magnetocrystalline anisotropy. Our systematic synthesis strategy and characterization may constitute a basis for achieving high quality co-doped SHFs in a customized way.
In this study, the structural, morphological, and magnetic properties of hydrothermally synthesized Co0.5Ni0.5BixFe2-xO4(x=0.00–0.10)nanosized spinel ferrites,(CoNiBiFO (x=0.00–0.10) NSFs), were ...investigated. The formation of CoNiBiFO NSFs phase was confirmed by X-ray diffraction (XRD). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed the morphology of the NSFs. Magnetization revealed that undoped Co0.5Ni0.5Fe2O4 and Co0.5Ni0.5BixFe2-xO4NSFs (except with x = 0.04) exhibit ferrimagnetic magnetism at 300 K. Only the hysteresis loops recorded from Co0.5Ni0.5Bi0.04Fe1.96O4NSFs have superparamagnetic characteristics. Mixed Co0.5Ni0.5Fe2O4NSFs have maximum remnant magnetization (Mr) of 23.5 emu/g, maximum saturation magnetization (MS) of 63.38 emu/g, and maximum magneton number (nB) 2.66 μB. However, Co0.5Ni0.5Bi0.04Fe1.96O4NSFs have minimum MS of 28.25 emu/g and minimum nB as 1.22 μB among Bi3+ doped and undoped samples. The coercivity (HC) of undoped Co0.5Ni0.5Fe2O4NSFs is 656 Oe. However, the Bi3+ ion-doped samples have a wide range of HC values between 101 Oe and 1038 Oe. The squareness ratios are in the range of 0.092–0.418 and multi-domain structure is assigned for all types of samples. The measured positive exchange bias (HE) magnitudes are 268 Oe and 290 Oe, respectively. Hysteresis loops recorded at 10 K proved that the products are ferrimagnetic. These coercivities showed that all the samples are magnetically harder at low temperatures. Positive HE values of 165 Oe and 297 Oe were measured from the nanoparticles (NPs) with x = 0.08 and x = 0.10 at 10 K. The SQR of the Co0.5Ni0.5Bi0.04Fe1.96O4 sample at 10 K is almost equal to the critical value of 0.5, and a single domain structure with uniaxial symmetry can be attributed for this sample. The other samples have SQRs in the range of 0.632–0.782 and multi-domain wall structure is assigned for them at 10 K.
Chromium-substituted strontium nano-hexaferrites, SrCrxFe12-xO19 (0.0 ≤ x ≤ 1.0), were produced by the hydrothermal route. The structure, morphology, optical and magnetic properties were studied. ...Crystal structure, spinel phase and functional groups were verified using X-ray diffraction and Fourier Transform Infrared spectroscopy. The average crystallites size is ranging between 50 and 67 nm. Scanning electron microscopy observations indicated that the multi-grains of the particles are aggleromated and are hexagonal in shape. The isotherm plots obtained from the nitrogen physisorption experiments showed that the mesopore area and the total pore volume decreased progressively with increasing the Cr3+ content. Besides, the band gap energy (Eg) decreases from 1.75 to 1.43 eV. The magnetic hysteresis loops showed that the produced nano-hexaferrites exhibit hard ferromagnetic-like (FM) behavior. Compared to the pristine SrFe12O19 product, the deduced saturation (Ms) and remanent (Mr) magnetizations, the coercivity (Hc) and the magnetocrystalline anisotropy field (Ha) increase for lower Cr3+ content (x ≤ 0.4) and then decrease as the Cr3+ content further increases. The squareness ratio Mr/Ms are ranging between 0.5 and 0.6, suggesting the single domain nano-sized particles with uniaxial anisotropy for various synthesized products. Mossbauer analysis was done to determine the quadrupole splitting, the isomer shift, and the hyperfine magnetic field values of all products.
Microspheres of Ni0.5Co0.5GaxFe2−xO4(x≤1.0) microsphere spinel ferrites (NiCoGaFe-MSFs) and carbon spheres were prepared via a hydrothermal technique. The microstructure of microspheres was ...investigated through scanning and transmission electron microscopy (SEM and TEM), respectively, and X-ray diffraction (XRD). The electrical and dielectric properties of NiCoGaFe-MSF at temperatures ranging from 20 to 120 °C (between 293.1 × 103 and 393.1 × 103) for f ≤ 3.0 MHz were systematically studied as a result of 3D graphical drawing of the data obtained from an impedance analyzer. Relevant parameters such as ac/dc conductivity, dielectric loss, dielectric constant, activation energy, dissipation factor and Cole–Cole impedance spectra were extensively evaluated for various Ga ion mole ratios in the substitution where x≤1.0. We notice that the ac conductivity mostly obeys exponential power law rules, which vary significantly with the substitution ratios of Ga ions. Impedance analyses confirm that differences in conduction mechanisms in NiCoGaFe-MSFs are mainly due to grain-to-grain boundaries related to Ga ion substitution ratios. The change in dielectric constant of NiCoGaFe-MSFs is strongly dependent on the substitution rates and results in a normal dielectric distribution with frequency. The tangential loss for all microspheres is observed to vary with measured temperatures and their frequency dependencies can be attributed to the conduction mechanism similar to Koop's phenomenological model. It is clearly seen that the formation of semicircles is dominated by all the NiCoGaFe-MSFs and the diameter of the semicircles mostly decreases with increasing temperature, as evidence of a temperature-dependent relaxation mechanism.
The ac conductivity values generally follow the exponential power-law rule as a function of bias frequency, and Ga ion substitution ratios were discovered to have an influence on the observed trends. Display omitted
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