Microwave-Assisted Preparation of Cu2O Octahedral Microcrystals

2011 ◽  
Vol 284-286 ◽  
pp. 746-749
Author(s):  
Chong Hai Deng ◽  
Han Mei Hu ◽  
Ming Di Yang

In this paper, we reported a facile microwave-assisted green chemical route to prepare pure, uniform, and monodispersed Cu2O octahedron wrapped by the {111} faces by using glucose as a reducing agent. X-ray diffraction (XRD), energy dispersive X-ray spectrometry(EDX) and field emission scanning electron microscopy (FESEM) were used to characterize the as-synthesized products. It was found that the morphology and structure of Cu2O crystals were greatly affected by the concentration of NaOH. A solid-solution-solid growth mechanism was possibly proposed on the basis of the comparative experimental results.

2008 ◽  
Vol 368-372 ◽  
pp. 995-997
Author(s):  
Cui Wei Li ◽  
Hong Xiang Zhai ◽  
Yang Zhou ◽  
Shi Bo Li ◽  
Zhi Li Zhang

In this study, free Ti/Si/Al/C powder mixtures with molar ratio of 3:0.4:0.8:1.8 were heated in Argon with various schedules, in order to reveal the possibility for the synthesis of Ti3Si0.4Al0.8C1.8 solid solution powder. X-ray diffraction (XRD) was used for the evaluation of phase identities of the powder after different treatments. Scanning electron microscopy (SEM) was used to observe the morphology of the Ti3Si0.4Al0.8C1.8 solid solution. XRD results showed that predominantly single phase samples of Ti3Si0.4Al0.8C1.8 was prepared after heating at 1400oC for 5 min in Argon and the lattice parameters of Ti3Si0.4Al0.8C1.8 lay between those of Ti3SiC2 and Ti3AlC2.


2005 ◽  
Vol 20 (10) ◽  
pp. 2741-2744 ◽  
Author(s):  
Huixing Lin ◽  
Wei Chen ◽  
Lan Luo

Phase-pure Ba2Ti9O20 powders were made by doping 3 wt% of V2O5 to a Ba:Ti = 2:9 molar composition, and the effects of the dopant on the phase formation were investigated. The study shows that BaTiO3, BaTi2O5, and BaTi4O9 were the intermediate phases before the formation of Ba2Ti9O20 for samples with or without V2O5. However, with V2O5 doping, the temperature at which Ba2Ti9O20 occurred were lowered from 1150 to 1050 °C and single phase Ba2Ti9O20 powders was easily obtained at 1150 °C for 2 h. Microstructure of the powders was examined by field emission scanning electron microscopy. No evidence of V2O5–Ba2Ti9O20 solid-solution was found by x-ray diffraction and energy-dispersive spectroscopy. The benefit of V2O5 to facilitate the Ba2Ti9O20 synthesis is most probably due to a vanadium-containing eutectic liquid phase which accelerates the migration of reactant species.


2011 ◽  
Vol 10 (06) ◽  
pp. 1209-1214 ◽  
Author(s):  
HUIZHAO ZHUANG ◽  
JIE WANG ◽  
XIAOKAI ZHANG ◽  
JUNLIN LI

Gallium nitride ( GaN ): nanostructured materials are synthesized by ammoniating Ga2O3/Nb films which are deposited in turn on Si(111) substrates at 900°C. The morphology and structure of the nanostructured materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Optical property of GaN nanostructured materials are analyzed by photoluminescence (PL). The results demonstrated that as-synthesized nanostructured materials are hexagonal wurtzite-structured. Ammoniating time of the samples has an evident influence on the morphology of GaN nanostructured materials synthesized by this method. The PL spectra indicate good emission property for the nanostructured materials. Finally, the growth mechanism is also briefly discussed.


2013 ◽  
Vol 661 ◽  
pp. 3-6 ◽  
Author(s):  
Yong Zhong Jin ◽  
Fa Ming Ye ◽  
Xian Guang Zeng ◽  
Rui Song Yang

Cr3C2-WC-Ni nanocomposite powders with ~50-100 nm were synthesized from precursors by vacuum-aided carbothermal reduction at only 750 °C for 2 h. The phase composition and microstructure of the synthesized products were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The present study shows that Cr3C2-WC-Ni nanocomposite powders contain two kinds of solid-solution phases, namely Ni and (Cr, W)3C2solid solution, respectively. WC and W2C phases do not appear inreaction products due to the dissolution of tungsten atoms into Ni and Cr3C2unit cells. Especially, there is a change of the crystalline structure for (Cr, W)3C2phase from 750 °C to 800 °C.


2012 ◽  
Vol 568 ◽  
pp. 348-351
Author(s):  
Shuang Xu ◽  
Nuan Song ◽  
Chang Li Qiu ◽  
Yao Ping Zhang ◽  
Jian Feng Wang

In this paper, a facile method was presented to fabricate CuS porous microspheres, which were formed by the intergrowth of CuS polycrystalline nanoslices. The obtained sample has been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electronic diffraction (SAED), and scanning electron microscopy (SEM). On the basis of the experimental results, we proposed a self-assemble mechanism to elucidate the formation of CuS nanoslice structure.


2013 ◽  
Vol 856 ◽  
pp. 197-200
Author(s):  
Adel Sakri ◽  
Ahmed Boutarfaia

View of the importance that has the development in the field of advanced technology transmission in human life, smart materials draws the attention of many researchers. In this contribution, we are interested in synthesizing a new smart material of the ceramic type based on Pb, Zr, Ti (PZT) doped La in the site A, and Sb, Zn in site B from a solid solution of pure oxides. The synthesized samples are thermally treated at 800°C. The techniques of x-ray diffraction (XRD) and SEM (scanning electron microscopy) are used to characterize the microstructure (the crystallographic phase), and the densities of the obtained samples were determined from their weights and volumes. The effect of sintering temperature on the microstructure properties was studied.


2012 ◽  
Vol 174-177 ◽  
pp. 516-519
Author(s):  
Yong Gang Wang ◽  
Lin Lin Yang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang

The BiFeO3 hollow crystals were successfully prepared at 200oC by a Al3+assisted hydrothermal method. The structures and morphologies of the as-obtained products were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (SEM). A morphology evolution from irregular shape to square, hollow, and sphere-like was observed as the Al ions concentration varied from 0% to 1.5%. The possible growth mechanism of the BiFeO3hollow crystals was also discussed.


2001 ◽  
Vol 688 ◽  
Author(s):  
E. Martínez ◽  
A. Fundora ◽  
O. Blanco ◽  
S. García ◽  
E. Heredia ◽  
...  

AbstractSrTiO3 and PbTiO3 perovskites are combined to form the xPbTiO3-(1−x)SrTiO3 (PST) solid solution. The effect of the PbTiO3 content on the microstructural and dielectric properties is studied for different compositions (x=0.1,0.3,0.5,0.7, and 0.9). Microstructural features of the PST system are studied by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques. Electrical properties are studied by the thermoelectric analysis technique at both fixed frequency and varying frequency to study the behavior of the dielectric constant and dielectric loss.Films of 0.5PbTiO3-0.5SrTiO3 (PST50) have been obtained by RF ion sputtering on different substrates. We investigate the relation between the crystalline structure and the dielectric properties of PST50 films deposited on different metallic films. Scanning Electron Microscopy (SEM) and X-Ray Diffraction were used for the structural analysis of the PST50/TiN/Si and PST50/RuO2/TiN /Si systems. The dielectric properties of the PST50 films were measured for TiN/PST50/TiN/Si, and RuO2/PST50/RuO2/TiN/Si capacitors and the results were correlated to the structure and composition. The charge storage capabilities of the PST50 films are evaluated for possible application in integrated circuit technology.


2008 ◽  
Vol 368-372 ◽  
pp. 409-411 ◽  
Author(s):  
Dao Yuan Yang ◽  
Fen Ling Qian ◽  
Kai Zhu ◽  
Zhan Ling Lu ◽  
Rui Zhang

Hexagonal MgAl2O4 spinel fibers were synthesized at 1500oC for 6h in nitrogen atmosphere. The structure and morphology of the fibers were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The fibers grew via vapor- liquid- solid mechanism. The twin mechanism was suggested to play a key role in the formation process of the hexagonal fibers.


2014 ◽  
Vol 936 ◽  
pp. 452-458
Author(s):  
Di Huo

The surface morphology and structure of the cubic stoichiometric spinel LiMn2O4powder prepared by microwave heating were examined using X-ray diffraction, scanning electron microscopy and transmittance electron microcopy. It is shown that the surface morphology of LiMn2O4particle changed with increasing preparing temperature, while the crystal structure kept unchanged. Novel nanostructured morphologies including nanorods and nanowhiskers were formed under appropriate synthesis conditions. The growth mechanism of the nanostructured morphology of spinel LiMn2O4was discussed in accordance with period bonding chains (PBCs) theory.


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