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The effects of 180, 210, and 230°C reaction temperatures on the structural and magnetic properties of synthesized iron sulfide nanoparticles were studied. The Rietveld refinement analysis result of the X‐ray diffraction data indicated that greigite was the dominant phase in all samples. The sample was prepared at 210°C for 18 h and had a greater wt% ratio of the greigite phase. The crystallite and particle sizes increased with increasing reaction temperatures. Scanning electron microscope images confirmed the presence of aggregation of synthesized rod‐shaped nanoparticles. The magnetic hysteresis curves of all samples showed ferromagnetic behavior at room temperature. The magnetic saturation of three samples increases with increased reaction temperature, but the coercive force has the opposite behavior. Antioxidant activity and cytotoxicity of the sample synthesized at 210°C were investigated. This sample killed cancer cells at relatively moderate and high concentrations with high viability of normal cells, demonstrating the sample's suitability for use in killing cancer cells while avoiding normal cells. [ABSTRACT FROM AUTHOR]

Stainless steel 316L (SS316L) as a significant bio-material, their wires were used to support the PMMA matrix. Two simple and low-cost surface pretreatments for SS316L wires were performed to enhance denture impact strength: mechanical scratching (treating SS316L wires with SiC powder inside a rotating container) and electrochemical anodizing. Three mechanical scratching samples for different periods of 60, 90 and 120min were prepared. Anodizing technique conditions were: Ethylene glycol with perchloric acid as an anodizing solution, 15V supplying and graphite rod as an anode. Anodizing process involved three pretreating periods of 15, 20, and 30min. All the prepared samples had dimensions of 65 × 10 × 3 mm. SEM technique showed different morphology nature involved holes, scratches and pores with a density of 104/μm2 and a crack length of 60μm. The PMMA reinforced with scratched stainless steel 316L wire surface for 120 min presented the highest impact strength value (42 kJ/m2) with (450.91%) increment. Anodizing samples showed a fluctuating behavior of samples with enhancing in the impact strength of anodizing wire for 20min of about 26.99 kJ/m2, which is still lower than that for scratched samples in average.

Nano nickel ferrite particles were prepared at pH values 1.5, 4, 7, 10, 13 by a hydrothermal method using metal chlorides and NaOH as an oxidant and solution basicity controller. There is a phase transition from hematite to spinel ferrite that begins when the pH reaches 4. The lowest crystallite size (4 nm) was associated with a highest lattice constant (8.345 Å), at pH=4. Whereas maximum crystallite size 64.5 nm corresponds lattice constant of 8.298 Å at pH=10. The highest magnetization (48 emu/g) value was achieved for the sample prepared at pH=7, which at the same time has a lower coercivity. The samples synthesized at pH ≥4 show superparamagnetic behavior owing to its low particle size and to zero field cooling and field cooling measurements. The ferromagnetic resonance (FMR) cavity tests analysis show that the broadened linewidth (770 Oe) and high imaginary permeability or high microwave absorption which is linked to high magnetization and low coercivity of superparamagnetic particles and their aggregation. There was a shift in the resonance field due to internal fields and cation distribution.

Four compositions of spinel NixBa1-xFe2O4 of x =0, 0.05, 0.01, and 0.15 were prepared by the autocombustion route. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Scanning Electron Microscopy (SEM) analyses were utilized to determine the structural properties. All samples showed a cubic spinel structure with a noticeable FTIR tetrahedral band blue shift as the molar ratio x was increased. The crystallite size and particle size have the same behavior as x changed from 0 to 0.15. Spherical nanoparticles aggregated into large clusters were found throughout the samples. Magnetic properties, displayed a drop in magnetization saturation as x increased to its max value. A saturation magnetization (Ms) of more than 48 emu/g was achieved at x = 0 and x = 0.15 while the coercivity did not change clearly. The fitting by the Langevin equation using Originlab software showed very close values of Ms to those measured by the vibrating sample magnetometer (VSM) test. Magnetic parameters are generally affected by both composition and particle size. [ABSTRACT FROM AUTHOR]

Nowadays, energy-related research is the main concern of researchers to find solutions to problems related to storage, such as thermal stability, and improve the efficiency and generation of energy in terms of energy correlation with the growth of the global economy. We successfully synthesized Nano-compositions based on (1 − x)BaCa0.05Ti0.95O3–(x)SrZn0.5Ti0.5O3 (x = 0.12, 0.14, 0.16, and 0.18) powders. Then, we made an optical ceramic device, such as a multilayer ceramic capacitor (MLCC), using the laser technique and electrodes from gold (Au) deposited on both sides of the coating layers using the sputtering technique. The obtained deposited film phase was investigated based on an X-ray diffractometer, which confirmed the formation of the tetragonal phase for the prepared specimens. The field emission scanning electron microscope test revealed that the increasing concentration of SrZnTiO3 (SZT) dopant in BaCaTiO3 (BCT) samples has improved the density of the composition. Further, electrical properties were improved by enhancement of dielectric constant when increased SZT quantity in the BCT system, as a result of the position of Zn2+‏ at the Sr2+‏ site in (SZT) dopant would be much more off-center, and the related dipole moments would also be big compared to that of Ca2+‏ in (BCT) composition. Furthermore, these composites showed thermal stability of dielectric constants and low-loss tangents. In addition, the optical characteristics of the samples investigated by UV–Vis are given in this article. [ABSTRACT FROM AUTHOR]

Nanoparticles of alpha ferric oxide (α -Fe2O3) were prepared by the hydrothermal method. Structural properties of α -Fe2O3 were determined by XRD, SEM and AFM measurements. The particles had a good matching with standard pattern. Average particle size was about 90 nm and the distribution extended from about 20 nm to 120 nm. Biocompatibility study of ferric oxide nanoparticles against bacteria, parasites, tumor cell line and normal cells was determined. No antibacterial activity was observed for the concentration, of ferric oxide nanoparticles in distilled water, up to 1.5 mg/ml vs. E. coli and S. aureus. Moreover, MTT assay was used to determine the cytotoxicity against parasites and cells. Intermediate cytotoxicity (53.30%) of 1.5 mg/ml of prepared nanoparticles was noted against L. tropica, while weak cytotoxicity of 5.20% was observed against L. donovani at the same concentration of ferric oxide nanoparticles. On the other hand, the prepared nanoparticles revealed low cytotoxicity (47.28%) against SR tumor cell line, while no cytotoxicity was shown against lymphocytes, as a model of normal cells. [ABSTRACT FROM AUTHOR]

Superparamagnetic particles of Ni ferrite prepared by co-precipitation technique were mixed with epoxy and studied by broadband ferromagnetic resonance (BFMR) in the range 2–26 GHz. The XRD and TEM showed that particles had a spinel structure and a small size around 27 nm. The particles exhibited a hysteresis loop with superparamagnetic behavior and the moment-temperature analyses showed a blocking temperature higher than room temperature. SC-BFMR analysis was based on measuring the diode voltage ratio when the sample is over the SC to the diode voltage when the sample is absent. The BFMR spectrums of Ni ferrite-epoxy composites were more refined at low fields than the higher one, when different phenomena were interfered. Below 5000 G, the resonant frequency-field relation was linear for all samples. The effective g-factor and effective magnetization calculated from resonant frequency field were generally decreased as Ni2+ was increased. The losses were represented as the inverse of the quality factor which was increased with Ni2+ content and was dropped as frequency was growing. [ABSTRACT FROM AUTHOR]