Synthesis of NiCu Alloy Nanoparticles by Arc Plasma Evaporation

2013 ◽  
Vol 710 ◽  
pp. 157-160
Author(s):  
Li Xin Li ◽  
Zhong Juan Yang ◽  
Ming Li

The NiCu nanoparticles were synthesized from NixCu1-x (20 at. % < x < 80 at. %) bulk alloys with arc plasma technique. The experimental results indicated that the crystal structure of the powders is face centered cubic structure, the same as the bulk raw materials. The composition between the prepared powders and the bulk alloys altered with the content of the nickel and copper. With Scherrer equation, the average crystallite size was determined to be 50 nm, which is consistent with the results achieved from the TEM (transmission electron microscopy) images. Also the TEM images showed that some of the nanoparticles could aggregate and grew into micro-size particles at room temperature. The largest size of the grown particle at room temperature was about 1 μm.

2003 ◽  
Vol 802 ◽  
Author(s):  
C. R. Krenn ◽  
M. A. Wall ◽  
A. J. Schwartz

ABSTRACTIn delta phase Pu-Ga alloys, the transformation from the ductile face-centered cubic (fcc) δ phase that is retained at room temperature to the brittle low-temperature monoclinic alpha-prime phase is a thermally activated diffusionless transformation with double-c kinetics. Accurate modeling of the phase transformation requires detailed understanding of the role of plastic flow during the transformation and of the crystallographic transformation path. Using transmission electron microscopy (TEM), we find a significant increase in dislocation density in δ near the α′ plates, which suggests that plastic deformation contributes to the accommodation of the 20% reduction in volume during the transformation. Analysis of a series of optical micrographs of partially transformed alloys suggests that the α′ habit plane is usually nearly perpendicular to <111> δ. However, a small number of TEM observations support a habit plane near <112> or <123>, in agreement with earlier work.


Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 903 ◽  
Author(s):  
Alba Garzón-Manjón ◽  
Hajo Meyer ◽  
Dario Grochla ◽  
Tobias Löffler ◽  
Wolfgang Schuhmann ◽  
...  

Controlling the amorphous or crystalline state of multinary Cr-Mn-Fe-Co-Ni alloy nanoparticles with sizes in the range between ~1.7 nm and ~4.8 nm is achieved using three processing routes. Direct current sputtering from an alloy target in the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide leads to amorphous nanoparticles as observed by high-resolution transmission electron microscopy. Crystalline nanoparticles can be achieved in situ in a transmission electron microscope by exposure to an electron beam, ex situ by heating in vacuum, or directly during synthesis by using a high-power impulse magnetron sputtering process. Growth of the nanoparticles with respect to the amorphous particles was observed. Furthermore, the crystal structure can be manipulated by the processing conditions. For example, a body-centered cubic structure is formed during in situ electron beam crystallization while longer ex situ annealing induces a face-centered cubic structure.


2012 ◽  
Vol 472-475 ◽  
pp. 1967-1970
Author(s):  
Cui Zhi Dong ◽  
Li Fang Zhang ◽  
Zhi Min Cui ◽  
Ming Xi Zhang ◽  
Qing Jun Zhang

ZnSe is important Ⅱ-Ⅵ semiconductor luminescence materials, and it is the structure of sphalerite and is the face-centered cubic crystal. W/O microemulsion method has the peculiarity of tester simpleness, easy manipulation, room temperature react etc. In this paper ZnSe nanometer line was synthesized in CTAB/cyclohexane/isobutanol/water quatemary microemulsion system. The morphology of the final products were characterized by transmission electron microscopy. according to the means, this paper researches the effect of aging time and the reactant contentration to nanometer materials. The result is that the nanometer line can be obtained through the different reactant concentration and the aging time under certain conditions. Finally, according to TEM chart, this paper infers the formation mechanism of the ZnSe.


Author(s):  
N.-H. Cho ◽  
S. McKernan ◽  
C.B. Carter ◽  
K. Wagner

Interest has recently increased in the possibility of growing III-V compounds epitactically on non-polar substrates to produce device quality material. Antiphase boundaries (APBs) may then develop in the GaAs epilayer because it has sphalerite structure (face-centered cubic with a two-atom basis). This planar defect may then influence the electrical behavior of the GaAs epilayer. The orientation of APBs and their propagation into GaAs epilayers have been investigated experimentally using both flat-on and cross-section transmission electron microscope techniques. APBs parallel to (110) plane have been viewed at the atomic resolution and compared to simulated images.Antiphase boundaries were observed in GaAs epilayers grown on (001) Ge substrates. In the image shown in Fig.1, which was obtained from a flat-on sample, the (110) APB planes can be seen end-on; the faceted APB is visible because of the stacking fault-like fringes arising from a lattice translation at this interface.


2012 ◽  
Vol 476-478 ◽  
pp. 1138-1141
Author(s):  
Zhi Qiang Wei ◽  
Qiang Wei ◽  
Li Gang Liu ◽  
Hua Yang ◽  
Xiao Juan Wu

Ag nanoparticles were successfully synthesized by hydrothermal method under the polyol system combined with traces of sodium chloride, Silver nitrate(AgNO3) and polyvinylpyrrolidone (PVP) acted as the silver source and dispersant respectively. The samples by this process were characterized via X-ray powder diffraction (XRD), Brunauer–Emmett–Teller (BET) adsorption equation, transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED) to determine the chemical composition, particle size, crystal structure and morphology. The experiment results indicate that the crystal structure of the samples is face centered cubic (FCC) structure as same as the bulk materials, The specific surface area is 24 m2/g, the particle size distribution ranging from10 to 50 nm, with an average particle size about 26 nm obtained by TEM and confirmed by XRD and BET results.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Somayeh Safat ◽  
Foad Buazar ◽  
Salim Albukhaty ◽  
Soheila Matroodi

AbstractThis contribution presents the biosynthesis, physiochemical properties, toxicity and photocatalytic activity of biogenic CeO2 NPs using, for the first time, marine oyster extract as an effective and rich source of bioreducing and capping/stabilizing agents in a one-pot recipe. CeO2 NPs formation was initially confirmed through the color change from light green to pale yellow and subsequently, their corresponding absorption peak was spectroscopically determined at 310 nm with an optical band-gap of 4.67 eV using the DR-UV technique. Further, XRD and Raman analyses indicated that nanoceria possessed face-centered cubic arrangements without any impurities, having an average crystallite size of 10 nm. TEM and SEM results revealed that biogenic CeO2 NPs was approximately spherical in shape with a median particle size of 15 ± 1 nm. The presence of various bioorganic substances on the surface of nanoparticles was deduced by FTIR and TGA results. It is found that marine-based nanoceria shows no cytotoxic effect on the normal cell, thus indicating their enhanced biocompatibility and biosafety to living organisms. Environmentally, due to energy band gap, visible light-activated CeO2 nanocatalyst revealed superior photocatalytic performance on degradation of methylene blue pollutant with removal rate of 99%. Owing to the simplicity, cost-effectiveness, and environmentally friendly nature, this novel marine biosynthetic route paves the way for prospective applications of nanoparticles in various areas.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3727
Author(s):  
Huanhuan He ◽  
Zhiwei Lin ◽  
Shengming Jiang ◽  
Xiaotian Hu ◽  
Jian Zhang ◽  
...  

The FeCoNiCrTi0.2 high-entropy alloys fabricated by vacuum arc melting method, and the annealed pristine material, are face centered cubic structures with coherent γ’ precipitation. Samples were irradiated with 50 keV He+ ions to a fluence of 2 × 1016 ions/cm2 at 723 K, and an in situ annealing experiment was carried out to monitor the evolution of helium bubbles during heating to 823 and 923 K. The pristine structure of FeCoNiCrTi0.2 samples and the evolution of helium bubbles during in situ annealing were both characterized by transmission electron microscopy. The annealing temperature and annealing time affect the process of helium bubbles evolution and formation. Meanwhile, the grain boundaries act as sinks to accumulate helium bubbles. However, the precipitation phase seems have few effects on the helium bubble evolution, which may be due to the coherent interface and same structure of γ’ precipitation and matrix.


2019 ◽  
Vol 19 (01) ◽  
pp. 1950003
Author(s):  
P. R. Ghutepatil ◽  
S. H. Pawar

In this paper, uniform and superparamagnetic nanoparticles have been prepared using one-step polyol synthesis method. Structural, morphological and magnetic properties of obtained MnFe2O4 nanoparticles have been investigated by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA) techniques. Structural investigation showed that the average crystallite size of obtained nanoparticles was about 10[Formula: see text]nm. Magnetic study revealed that the nanoparticles were superparamagnetic at room temperature with magnetization 67[Formula: see text]emu/g at room temperature. The self-heating characteristics of synthesized MnFe2O4 nanoparticles were studied by applying external AC magnetic field of 167.6 to 335.2[Formula: see text]Oe at a fixed frequency of 265[Formula: see text]kHz. The SAR values of MnFe2O4 nanoparticles were calculated for 2, 5, 10[Formula: see text]mg[Formula: see text]mL[Formula: see text] concentrations and it is observed that the threshold hyperthermia temperature is achieved for all concentrations.


1997 ◽  
Vol 3 (S2) ◽  
pp. 413-414
Author(s):  
E.M. Hunt ◽  
J.M. Hampikian ◽  
N.D. Evans

Ion implantation can be used to alter the optical response of insulators through the formation of embedded nano-sized particles. Single crystal alumina has been implanted at ambient temperature with 50 keV Ca+ to a fluence of 5 x 1016 ions/cm2. Ion channeling, Knoop microhardness measurements, and transmission electron microscopy (TEM) indicate that the alumina surface layer was amorphized by the implant. TEM also revealed nano-sized crystals ≈7 - 8 nm in diameter as seen in Figure 1. These nanocrystals are randomly oriented, and exhibit a face-centered cubic structure (FCC) with a lattice parameter of 0.409 nm ± 0.002 nm. The similarity between this crystallography and that of pure aluminum (which is FCC with a lattice parameter of 0.404 nm) suggests that they are metallic aluminum nanocrystals with a slightly dilated lattice parameter, possibly due to the incorporation of a small amount of calcium.Energy-filtered transmission electron microscopy (EFTEM) provides an avenue by which to confirm the metallic nature of the aluminum involved in the nanocrystals.


2021 ◽  
Author(s):  
M. Sohail ◽  
Adnan Shahzad ◽  
Mian Gul Sayed ◽  
Ihsan Ullah ◽  
M. Omer ◽  
...  

Abstract In the present study, ceramic wastes collected from the premises of industrial zone in Peshawar, KP Pakistan were investigated. An effort has been made to recycle and use the ceramic wastes as fillers in polymeric composites. The negative cost ceramic wastes were purified and activated thermally. The elemental composition and pellets of the wastes were investigated through SEM/EDX analysis. Waste/Polyaniline (PANI) composite was synthesized via in-situ free radical polymerization technique. SEM of the composites showed the uniform distribution of fillers particles in the PANI matrix. XRD studies confirmed that the prepared composite material had a face- centered cubic geometry with distinct preferential orientations. Dielectric analysis showed that the materials exhibit active performance at high frequency regions (3MHz to 3GHz) at room temperature. The results show decrease in dielectric losses and capacitance (1.6 pF) at high frequency regions. AC conductivity of the composite has been increased up to 37.95 Scm-1. This revealed the effect of PANI on the ceramic wastes while increasing its conductance performance. This suggests that the composite material can be investigated for use in photovoltaic detectors, electro-responsive capacitors and power applications.


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