The Morphology and Phases of Ni-Se Powders Prepared by Hydrothermal Method

2010 ◽  
Vol 29-32 ◽  
pp. 1820-1823
Author(s):  
Ke Gao Liu ◽  
Ya Liu ◽  
Bin Xu

Ni-Se powders synthesized by hydrothermal co-reduction method from NiCl2.6H2O and SeO2 at 95~220 °C. The phases and morphology of the products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) respectively. Experimental results show that, Ni0.85Se can be synthesized at 95~220 °C while noticeable impurities appeared at lower reaction temperatures. The products with single-phase Ni0.85Se obtained at 200 and 220 °C show hollow sphere structures with diameters of about 150 ~ 700 nm, which have complete and regular shape but no holes.

2011 ◽  
Vol 412 ◽  
pp. 263-266
Author(s):  
Hong Wei Zhang ◽  
Li Li Zhang ◽  
Feng Rui Zhai ◽  
Jia Jin Tian ◽  
Can Bang Zhang

The higher mechanical strength of Al87Ce3Ni8.5Mn1.5 nanophase amorphous composites has been obtained with two methods. The first nanophase amorphous composites are directly produced by the single roller spin quenching technology. The method taken for the second nanophase amorphous composites is at first to obtain amorphous single-phase alloy, followed by annealed at different temperatures .The formative condition, the microstructure, the particle size, the volume fraction of α-Al phase and microhardness of nanophase amorphous composites etc have been investigated and compared by X-ray diffraction (XRD) and transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The microstructure of composites produced by the second method is higher than the former, the fabricated material structure of the system is more uniform and the process is easier to control.


2011 ◽  
Vol 179-180 ◽  
pp. 141-144
Author(s):  
Ke Gao Liu ◽  
Shi Lei ◽  
Bin Xu ◽  
Ya Liu

Cu-In-2Se powders were synthesized by hydrothermal co-reduction method from CuCl2.2H2O, InCl3.4H2O and SeO2 at 95~200 °C in deionized water. The morphology and phases of the products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) respectively. Experimental results show that, CuInSe2 can be obtained at 120~200 °C, the major phase of the products synthesized at 120~200 °C are all the same. However the noticeable impurity phase In(OH)3 still exists in the product powders. The In(OH)3 phase decreases with the increasing of reacting temperature. The product powder obtained at 200 °C has fine and homogeneous particles with diameters of about 500 nm.


2012 ◽  
Vol 02 (01) ◽  
pp. 1250007 ◽  
Author(s):  
LAXMAN SINGH ◽  
U. S. RAI ◽  
K. D. MANDAL ◽  
MADHU YASHPAL

Ultrafine powder of CaCu2.80Zn0.20Ti4O12 ceramic was prepared using a novel semi-wet method. DTA/TG analysis of dry powder gives pre-information about formation of final product around 800°C. The formation of single phase was confirmed by X-ray diffraction analysis. The average particle size of sintered powder of the ceramic obtained from XRD and Transmission electron microscopy was found 59 nm and 102 nm, respectively. Energy Dispersive X-ray studies confirm the stoichiometry of the synthesized ceramic. Dielectric constant of the ceramic was found to be 2617 at room temperature at 1 kHz.


2001 ◽  
Vol 15 (30) ◽  
pp. 1455-1458 ◽  
Author(s):  
H. CHEN ◽  
X. K. LU ◽  
S. Q. ZHOU ◽  
X. H. HAO ◽  
Z. X. WANG

Single phase AlN nanowires are fabricated by a sublimation method. They were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), typical selected area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM). The SEM and TEM images show that most of the nanowires have diameters of about 10–60 nm. The crystal structure of AlN nanowires revealed by XRD, SAED and HRTEM shows the AlN nanowires have a wurtzite structure.


2002 ◽  
Vol 755 ◽  
Author(s):  
Susanthri C. Perera ◽  
Stephanie L. Brock

ABSTRACTThe formation of single phase FeP nanocrystals has been achieved by the reaction of Fe(III) salts (iron(III)acetylacetonate (Fe(acac)3) and iron(III)chloride (FeCl3)) with tris(trimethylsilyl)phosphine in trioctylphosphine oxide (TOPO)/trioctylphosphine (TOP) at elevated temperatures. The sizes of nanoparticles formed differ markedly depending on the initial iron salt used. Use of Fe(acac)3 always resulted in comparatively bigger particle formation (∼5 nm) while FeCl3 forms much smaller particles (∼1 nm) as confirmed by powder X-ray diffraction (XRD) and transmission electron microscopy (TEM).


2017 ◽  
Vol 727 ◽  
pp. 395-402
Author(s):  
Zi Run Wang ◽  
Xin Liu ◽  
Gui Qi Xie ◽  
Yi Wu ◽  
Ming Nie ◽  
...  

Cu-Ag alloy nanoparticles were synthesized by a liquid phase reduction method. Using sodium formaldehyde sulfoxylate (SFS) as reducing agents, copper-silver bimetallic nanoleaflets with high content of Cu were prepared. The obtained Cu-Ag bimetallic nanocrystal were characterized by powder X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscope (FESEM), high resolution transmission electron microscopy (HRTEM) and transmission electron microscopy (TEM). Different molar ratio of Cu-Ag bimetallic nanomaterials could produce different morphologies. The surfactant β-CD plays a crucial role on the structure of the products. The different molar ratios of Cu-Ag were also investigated. The electrochemical activity was evaluated using cyclic voltammetry (CV), electrochemical hydrogen evolution reaction (HER) in a 0.5M Na2SO4 electrolyte.


2010 ◽  
Vol 29-32 ◽  
pp. 1824-1827
Author(s):  
Ke Gao Liu ◽  
Bo Pang ◽  
Zhi Gang Wang ◽  
Bin Xu

Cu-Se compound powders are synthesized by hydrothermal co-reduction from CuSO4•5H2O and SeO2 in deionized water at 120~200 °C. The phases and morphology of the products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) respectively. Experimental results show that, the CuSe phase can be synthesized at 120,150,180 and 200 °C, however, the purity phases become more with the temperature decreasing. It indicates that the reaction is more incomplete at lower temperature. Hexagonal flakes with side length 100~400 nm can be observed in the products at 150,180 and 200 °C, among which only the product prepared at 180 °C has the hexagonal flakes with good dispersity and homogeneous size with 200 nm length.


2012 ◽  
Vol 503-504 ◽  
pp. 637-640
Author(s):  
Yuan Xing Cai ◽  
Ke Gao Liu

The technologies of synthesizing Ni-S powders from 0.001 mol NiCl2•6H2O and 0.001 mol sulfur (S) powder were investigated at 95,105,120,140 and 160 °C. The phases and morphology of the products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) respectively. Experimental results show that, the Ni-S powders prepared at 120~160 °C from NiCl2•6H2O and S powder have the same major phase NiS. These products have flakes or unregular shape grains with sizes of 100~200nm. However, the product powder prepared at 105 °C has the major phase Ni3S2 without obvious impurity phases and only grains with size less than 200nm. No Nickel sulfides can be synthesized at 95 °C under the experimental conditions. It can be found that the NiS phase appears in the products powders obtained at higher temperatures while Ni3S2 obtained at lower temperature.


2007 ◽  
Vol 336-338 ◽  
pp. 2037-2040
Author(s):  
Moon Hee Choi ◽  
Yoon Bok Lee ◽  
In Bae Kim ◽  
Young Seok Kim ◽  
Young Mok Rhyim ◽  
...  

Cadmium selenide (CdSe) of hollow sphere with 30-50nm in diameter have been prepared form the mixed solution of cadmium chloride (CdCl2), sodium selenosulfate(Na2SeSO3) and ethylenediamine (H2NCH2CH2NH2) at room temperature. The hollow sphere of CdSe was characterized by transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). The molar ratio of EDA to Cd2+ ions in this system was important factor on controlled synthesis in the self-encapsulated morphology. Based on the observation on morphological difference with molar ratio of EDA to Cd2+ ion, the possible mechanism for the formation of CdSe hollow sphere was discussed.


Author(s):  
R. Gronsky

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.


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