scholarly journals Preparation of Nanoparticles in an Eco- friendly Method using Thyme Leaf Extracts

2020 ◽  
Vol 17 (2(SI)) ◽  
pp. 0670
Author(s):  
Jomana Rakaa et al.

Colloidal silver nanoparticles were prepared by single step green synthesis using aqueous extracts of the leaves of thyme as a function of different molar concentration of AgNO3 (1,2,3,4 mM(. The Field Emission Scanning Electron Microscopy (FESEM), UV-Visible and X-ray diffraction (XRD) were used to characterize the resultant AgNPs. The surface Plasmon resonance was observed at wavelength of 444 nm. The four intensive peaks of XRD pattern indicate the crystalline nature and the face centered cubic structure of the AgNPs. The average crystallite size of the AgNPs ranged from 18 to 22 nm. The FESEM image illustrated the well dispersion of the AgNPs and the spherical shape of the nanoparticles with a particle size distribution between 13 to 50 nm.

2020 ◽  
Vol 19 (05) ◽  
pp. 1950040 ◽  
Author(s):  
Neran Ali Thamer ◽  
Ban. H. Adil ◽  
A. S. Obaid

In this study, gold nanoparticles were synthesized in a single step biosynthetic method using aqueous leaves extract of thymus vulgaris L. It acts as a reducing and capping agent. The characterizations of nanoparticles were carried out using UV-Visible spectra, X-ray diffraction (XRD) and FTIR. The surface plasmon resonance of the as-prepared gold nanoparticles (GNPs) showed the surface plasmon resonance centered at 550[Formula: see text]nm. The XRD pattern showed that the strong four intense peaks indicated the crystalline nature and the face centered cubic structure of the gold nanoparticles. The average crystallite size of the AuNPs was 14.93[Formula: see text]nm. Field emission scanning electron microscope (FESEM) was used to study the morphology of the AuNPs. AuNPs exhibited a spherical shape with diameters ranging 13–53[Formula: see text]nm. The synthesized stable gold nanoparticles showed more significant anticancer activity against MCF-7 and CAL-51 cells after 48[Formula: see text]h.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Tizazu Abza ◽  
Dereje Gelanu Dadi ◽  
Fekadu Gashaw Hone ◽  
Tesfaye Chebelew Meharu ◽  
Gebremeskel Tekle ◽  
...  

Cobalt sulfide thin films were synthesized from acidic chemical baths by varying the deposition time. The powder X-ray diffraction studies indicated that there are hexagonal CoS, face-centered cubic Co3S4, and cubic Co9S8 phases of cobalt sulfide. The crystallite size of the hexagonal CoS phase decreased from 52.8 nm to 22.5 nm and that of the cubic Co9S8 phase increased from 11 nm to 60 nm as the deposition time increased from 2 hrs to 3.5 hrs. The scanning electron microscopic images revealed crack and pinhole free thin films with uniform and smooth background and few large polygonal grains on the surface. The band gap of the cobalt sulfide thin films decreased from 1.75 eV to 1.3 eV as the deposition time increased from 2 hrs to 3.5 hrs. The photoluminescence (PL) spectra of the films confirmed the emission of ultraviolet, violet, and blue lights. The intense PL emission of violet light at 384 nm had red shifted with increasing deposition time that could be resulted from the increase in the average crystallite size. The FTIR spectra of the films indicated the presence of OH, C-O-H, C-O, double sulfide, and Co-S groups. As the deposition time increased, the electrical resistivity of the cobalt sulfide thin films decreased due to the increase in both the crystallite size and the films’ thickness.


2013 ◽  
Vol 22 ◽  
pp. 169-172
Author(s):  
B. SONI ◽  
S. BISWAS

We report a novel synthesis technique of ceria nanoparticles by a sol-gel type chemical process using poly-vinyl alcohol (PVA) as a capping as well as a reducing agent. The as-synthesized CeO 2 nanoparticles were characterized by X-ray diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM). The XRD analysis reveals the fluorite type face centered cubic structure in the ceria nanoparticles with an average crystallite size of 6 nm and 9 nm for the samples calcined at 350°C and 400°C, respectively.


2011 ◽  
Vol 335-336 ◽  
pp. 429-432 ◽  
Author(s):  
Xiu Yu Sun ◽  
Fa Qiang Xu

Highly ordered Cu, Ag and Au nanowire arrays with high aspect ratio and highly dense self-supporting nanowire patterns of copper group were successfully prepared using cyclic voltammetry with the assistance of anodic aluminum oxide (AAO) template. The X-ray diffraction (XRD) patterns of the metal nanowries were indexed to the face-centered cubic structure. The field emission scanning electron microscope (FE-SEM) results demonstrated that the length of nanowire could be controlled by changing the electrodepositon conditions. The aspect ratio of nanowire arrays can be tuned.


2013 ◽  
Vol 8 (4) ◽  
pp. 155892501300800 ◽  
Author(s):  
Dawei Gao ◽  
Lili Wang ◽  
Xin Xia ◽  
Hui Qiao ◽  
Yibing Cai ◽  
...  

Two polymer solutions of polyacrylonitrile, polyvinyl pyrrolidone, and Ni(CH3COOH)2 in dimethylformamide were electrospun into ternary composite nanofibers, followed by stabilization and carbonization processes to obtain porous carbon/nickel composite nanofibers with diameters of 100–200 nm. The study revealed that carbon/nickel composite nanofibers were successfully prepared, which allowed nickel particles with diameters of 20–70 nm to be uniformly distributed in the carbon nanofibers. It was also observed that the fibrous structures with particles embedded formed and the fibers broke into shorter fibers after sintering. X-ray diffraction indicated that embedded particles crystallized with the face centered cubic structure. The Brunauer-Emmett-Teller analysis revealed that carbon/nickel composite nanofibers with meso-pores possessed larger specific surface area than that of carbon nanofibers. The specific capacitance of the composite nanofiber electrode was as high as 103.8 F/g and showed stable cyclicity (73.8%).


1994 ◽  
Vol 9 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Alan F. Jankowski ◽  
Mark A. Wall

The artificial layering of metals can change both physical and structural characteristics from the bulk. The stabilization of polymorphic metallic phases can occur on a dimensional scale that ranges from single overgrowth layers to repetitive layering at the nanoscale. The sputter deposition of crystalline titanium on nickel, as both a single layer and in multilayer form, has produced a face-centered cubic phase of titanium. The atomic structure of the face-centered cubic titanium phase is examined using high resolution electron microscopy in combination with electron and x-ray diffraction.


2008 ◽  
Vol 368-372 ◽  
pp. 1389-1391 ◽  
Author(s):  
Shuan Gui Qing ◽  
Bo Liu ◽  
Xun Liang ◽  
Hai Yang Li ◽  
Wei Zhong Lv ◽  
...  

Multilayer SiO2 crystals modified by alkoxysilanes were fabricated by the vertical deposition technique combined with self-assembly method. The SiO2 colloidal crystallization was prepared by the traditional Stöber-Fink-Bohn method, and modified by different alkoxysilanes to investigate the properties of the films. The films fabricated by the ordering of SiO2 spheres were investigated by infrared spectrometer, X-ray diffraction, scanning electron microscope, UV-visible spectrophotometer. The results showed that thin film is the face-centered cubic structures and the spheres are [111]-oriented.


1999 ◽  
Vol 562 ◽  
Author(s):  
Heng Gong ◽  
Wei Yang ◽  
Maithri Rao ◽  
David E. Laughlin ◽  
David N. Lambeth

ABSTRACTThin Co and Co based alloy films with the face centered cubic (FCC) structure have been epitaxially grown on single crystal Si wafers by sputter deposition. Epitaxial orientation relationships have been determined by x-ray diffraction, x-ray pole figure scans and TEM. Magnetic properties have been characterized using vibrating sampling magnetometer (VSM), torque magnetometer and BH loop tracer. Soft magnetic properties have been observed for the pure Co films.


2021 ◽  
Vol 236 (3-4) ◽  
pp. 71-80
Author(s):  
Sivaprasad Ghanta ◽  
Anustoop Das ◽  
Rajat Kamboj ◽  
Partha P. Jana

Abstract The T phase in the Mn–Ni–Zn system was obtained as a product of high-temperature solid-state syntheses from the loaded composition of MnxNi2−xZn11 (x = 0.2–1.5)/MnxNi15.38−xZn84.62 (x = 1.54–11.54). The crystal structure of the T phase has been explored by means of X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). The structures were solved in the face-centered cubic space group F 4 ‾ 3 m $F‾{4}3m$ (216) and contain 409–410 atoms/unit cell. The lattice constants were found to be a = 18.1727(2) and 18.1954(1) Å for crystals C1 and C2, respectively. The crystal structure denoted the T phase is a (2aγ)3-superstructure of the ordinary cubic γ-brass-type phase. The phase is isostructural to (Fe, Ni)Zn6.5. A “cluster” description has been used to visualize the crystal structure of the title phase. The structures have been constructed by the five distinct clusters and they are situated about the high symmetry sites of the face-centered cubic lattice. The T phase is stabilized at a valance electron concentration of 1.78, which is slightly higher than those expected for typical γ-brass Hume‐Rothery compounds.


MRS Bulletin ◽  
1997 ◽  
Vol 22 (7) ◽  
pp. 33-37 ◽  
Author(s):  
Tohru Suzuki

In 1916 a group of Russian chemists—Kurnakov and his colleagues—discovered that slowly cooled CuxAu1 − xmetal alloys had anomalously low electrical resistivities at simple compositions of CuAu and Cu3Au. Nine years later in 1925, Swedish physicists Johansson and Linde found by x-ray-diffraction experiments that the alloys had ordered structures on the face-centered-cubic lattice, now called CuAu I-type and AuCu3-type. Two years later, Johansson and Linde discovered CuPt-type ordering in Cu0.5Pt0.5 alloy by noticing a similar anomaly in their electrical-resistivity measurements for CuxPt1 − x. These were among the events at the dawn of physical metallurgy and study on order-disorder transformations. Many years later in 1985, the first observation of ordering in semiconductor alloys was made in AlGaAs grown on GaAs(110); the type was CuAu I. CuPt-type ordering was observed in SiGe grown on Si(001). Since the (110) orientation of the substrate for AlGaAs was clumsy for practical purposes and the degree of ordering in SiGe was extremely low, these phenomena seemed to have little relevance in practical applications. Other observations were made such as famatinite-type ordering in GalnAs and chalcopyrite-type ordering in GaAsSb. These observations however were quite rare, with only isolated cases reported.


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