Preheating Effects on Bi2S3 Morphology Synthesized via Hydrothermal Method

2013 ◽  
Vol 631-632 ◽  
pp. 298-302
Author(s):  
Xi Liang Chen ◽  
Kai Yan ◽  
Hong Ying Chu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Composition ◽  
Great Effort ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Phase ◽  
Hydrothermal Approach ◽  
Scanning Electron

Bi2S3nanorod, nanobelt and flowerlike patterns were synthesized via a facile hydrothermal approach without using any surfactant and acid. The morphology, structure, phase composition, and photoluminescence properties of the as-prepared Bi2S3products were characterized using various techniques (scanning electron microscopy, X-ray diffraction, and photoluminescence spectroscopy). The experimental results showed that the preheating process had a great effort on the morphology of the product.

Bi2S3 Nanoflowers Synthesized via Hydrothermal Method

2014 ◽  
Vol 989-994 ◽  
pp. 11-14 ◽  
Author(s):  
Xi Liang Chen ◽  
Yan Pei Ji
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Composition ◽  
High Resolution ◽  
Hydrothermal Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Phase ◽  
Hydrothermal Approach ◽  
Scanning Electron

Bi2S3 flowerlike patterns were synthesized via a facile hydrothermal approach without using any surfactant and acid. The morphology, structure, phase composition, of the as-prepared Bi2S3 products were characterized using scanning electron microscopy, X-ray diffraction, high-resolution transmission and electron microscopy, respectively. The experimental results showed that the product possesses good distribution of morphology, well crystallized nanostructure.

UTILIZATION OF FLY ASH AND CONCRETE RESIDUE IN THE PRODUCTION OF GEOPOLYMER BRICKS

2017 ◽  
Vol 12 (1) ◽  
pp. 63-77 ◽  
Author(s):  
Siriporn Sirikingkaew ◽  
Nuta Supakata
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Compressive Strength ◽  
Phase Composition ◽  
Fly Ash ◽  
Industrial Waste ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

This study presents the development of geopolymer bricks synthetized from industrial waste, including fly ash mixed with concrete residue containing aluminosilicate compound. The above two ingredients are mixed according to five ratios: 100:0, 95:5, 90:10, 85:15, and 80:20. The mixture's physico-mechanical properties, in terms of water absorption and the compressive strength of the geopolymer bricks, are investigated according to the TIS 168-2546 standard. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses are used to investigate the microstructure and the elemental and phase composition of the brick specimens. The results indicate that the combination of fly ash and concrete residue represents a suitable approach to brick production, as required by the TIS 168–2546 standard.

scholarly journals Standard Hot Pressing as a Possible Solution to Obtain Dense K0.5Na0.5NbO3 Ceramic Doped by Er2O3 and Yb2O3

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4171 ◽  
Author(s):  
Paweł Rutkowski ◽  
Jan Huebner ◽  
Adrian Graboś ◽  
Dariusz Kata ◽  
Dariusz Grzybek ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Rare Earth ◽  
Phase Composition ◽  
Powder Mixture ◽  
Hot Pressing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ultrasonic Methods ◽  
Scanning Electron

In this study, the influence of the addition of rare earth oxides on the phase composition and density of KNN piezoelectric ceramics was investigated. The initial powders of Na2CO3 and K2CO3 were dried at 150 °C for 2 h. Then, a powder mixture for synthesis was prepared by adding a stoichiometric amount of Nb2O5 and 5 and 10 wt % overabundance of Na2CO3. All powders were mixed by ball-milling for 24 h and synthesized at 950 °C. The phase composition of the reaction bed was checked by means of X-ray diffraction (XRD). It had an appearance of tetragonal and monoclinic K0.5Na0.5NbO3 (KNN) phases. Then, 1 and 2 wt % of Er2O3 and Yb2O3, were added to the mixture. Green samples of 25 mm diameter and 3 mm thickness were prepared and sintered by hot pressing at 1000 °C for 2 h under 25 MPa pressure. The final samples were investigated via scanning electron microscopy (SEM)-energy-dispersive X-ray spectroscopy (EDS), XRD, Rietveld, and ultrasonic methods. Phase analysis showed tetragonal and orthorhombic KNN phases, and a contamination of (K2CO3·1.5H2O) was present. The obtained KNN polycrystals had a relative density above 95%. Texturing of the material was confirmed as a result of hot pressing.

Microstructure and Phase Composition of AlN/Al Composite Fabricated by Directed Melt Nitridation

2008 ◽  
Vol 368-372 ◽  
pp. 977-979
Author(s):  
Sheng Li Jin ◽  
Ya Wei Li ◽  
Jing Liu ◽  
Yuan Bing Li ◽  
Lei Zhao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Composition ◽  
Sandwich Structure ◽  
Ceramic Composite ◽  
Growth Direction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Al Composite ◽  
Scanning Electron

AlN/Al ceramic composite was fabricated by directed melt nitridation of pure Al block covered with 10wt% Mg powder at 1300°C in a high purity flowing N2. Microstructure and phase composition of the composite were investigated by scanning electron microscopy with energy dispersive spectroscopy and X-ray diffraction. Results showed that AlN is the main phase in the composite and its lattice parameters of a and c are 3.1110Å and 4.9806Å, respectively. The phase composition of the composite changes along the growth direction and a gradient sandwich structure forms. The surface of the composite is made up of a dense and thin nodular AlN layer, underneath which an AlN/Al layer appears, followed by an AlN/Al/MgAl2O4 layer. Thermodynamic calculations predicted the formation of possible phases with the addition of Mg. It suggested that the content of Mg at the reaction frontier of nitridation is considerably lower to 0.15wt% where MgAl2O4 was stable, because of escape and reaction exhaustion of Mg. Once Mg is lower than 0.05wt%, only a dense AlN layer can exist, which prevents the further nitridation of Al melt.

Biomorphic SiC Prepared from Carbonized Millet by Sol-Gel and Carbothermal Reduction Processing

2010 ◽  
Vol 152-153 ◽  
pp. 1683-1686
Author(s):  
Qing Wang ◽  
Ya Hui Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silicon Carbide ◽  
Phase Composition ◽  
Carbothermal Reduction ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon Template ◽  
Scanning Electron

Biomorphic silicon carbide (bioSiC) was prepared by high temperature pyrolysis and sol-gel and carbothermal reduction processing at 1600 oC. The morphology and microstructure of carbon-silica composites and purified bioSiC samples were characterized by scanning electron microscopy. The phase composition of the resulting sample was analyzed by X-ray diffraction. The results suggest that the bioSiC mainly consists of cubic ß-SiC, and principally replicates the shape and microstructure of the carbon template.

Biomorphic TiO2 Ceramics Prepared from Cotton Stalk

2012 ◽  
Vol 602-604 ◽  
pp. 526-529
Author(s):  
Qing Wang ◽  
Lin Zhang ◽  
Ya Hui Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Composition ◽  
High Temperature ◽  
Sol Gel ◽  
Cotton Stalk ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon Template ◽  
Scanning Electron

Biomorphic TiO2 was prepared by high temperature pyrolysis and a modified sol-gel route. The morphology and microstructure of TiO2 samples were characterized by scanning electron microscopy. The phase composition of the resulting sample was analyzed by X-ray diffraction. The results suggest that the biomorphic TiO2 mainly consists of rutile TiO2, and replicates the shape and part microstructure of the carbon template.

scholarly journals Evolution of Free Volumes in Polycrystalline BaGa2O4 Ceramics Doped with Eu3+ Ions

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1515
Author(s):  
Halyna Klym ◽  
Ivan Karbovnyk ◽  
Andriy Luchechko ◽  
Yuriy Kostiv ◽  
Viktorija Pankratova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Composition ◽  
Grain Boundaries ◽  
Solid Phase ◽  
X Ray Diffraction ◽  
Spectroscopy Technique ◽  
X Ray ◽  
Positron Annihilation Lifetime ◽  
Scanning Electron

BaGa2O4 ceramics doped with Eu3+ ions (1, 3 and 4 mol.%) were obtained by solid-phase sintering. The phase composition and microstructural features of ceramics were investigated using X-ray diffraction and scanning electron microscopy in comparison with energy-dispersive methods. Here, it is shown that undoped and Eu3+-doped BaGa2O4 ceramics are characterized by a developed structure of grains, grain boundaries and pores. Additional phases are mainly localized near grain boundaries creating additional defects. The evolution of defect-related extended free volumes in BaGa2O4 ceramics due to the increase in the content of Eu3+ ions was studied using the positron annihilation lifetime spectroscopy technique. It is established that the increase in the number of Eu3+ ions in the basic BaGa2O4 matrix leads to the agglomeration of free-volume defects with their subsequent fragmentation. The presence of Eu3+ ions results in the expansion of nanosized pores and an increase in their number with their future fragmentation.

Synthesis and Photoluminescence of Rhombic NaLa(MoO4)2:Ln3+ Nanocrystals

2016 ◽  
Vol 16 (4) ◽  
pp. 3617-3621 ◽  
Author(s):  
Yuping Wang ◽  
Mingxia Li ◽  
Kai Pan ◽  
Rong Li ◽  
Naiying Fan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Raman Spectroscopy ◽  
Luminescence Intensity ◽  
Dopant Concentration ◽  
Emission Spectra ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Rhombic NaLa(MoO4)2:Ln3+ (Ln = Eu and Tb) nanocrystals were synthesized by a hydrothermal method. The structures and morphologies of the nanocrystals were characterized by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. The results indicated that the crystalline size increased with increasing Na2MoO4 content. The photoluminescence properties of NaLa(MoO4)2:Ln3+ nanocrystals were investigated in detail. In the emission spectra of NaLa(MoO4)2:Eu3+ nanocrystals, the 5D0 → 7F2 is dominant, and the peak positions and spectral shapes of emissions were independent of Eu3+ concentration. The luminescence intensity increased with increasing Eu3+ concentration, up to about 10 mol%, and then decreased. In the emission spectra of NaLa(MoO4)2:Tb3+ nanocrystals, the 5D4 → 7F5 is dominant. The sample with a dopant concentration of 20 mol% showed the highest emission intensity.

Preparation of Biomorphic SiC by Reactive Infiltration of Gaseous Si into Carbonized Millet

2010 ◽  
Vol 152-153 ◽  
pp. 1673-1676
Author(s):  
Qing Wang ◽  
Ya Hui Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silicon Carbide ◽  
Phase Composition ◽  
Pyrolysis Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reactive Infiltration ◽  
Carbon Template ◽  
Scanning Electron

Biomorphic silicon carbide (bioSiC) was prepared at 1800 oC by reactive infiltration of gaseous silicon into a carbon template derived from millet. The pyrolysis process of millet was measured by thermogravimetric analysis. The morphology and microstructures of carbon template and purified bioSiC samples were characterized by scanning electron microscopy. The phase composition of bioSiC was analyzed by X-ray diffraction. The results suggest that the bioSiC consists of major cubic ß-SiC and a few α-SiC, and principally replicates the shape and microstructure of the carbon template.

Study on the Surface Morphologies of Nickel-Phosphorus Ultra-Black Films

2014 ◽  
Vol 924 ◽  
pp. 166-169 ◽  
Author(s):  
Pan Pan Yue ◽  
Yong Zhong Jin ◽  
Xu Dong Hu ◽  
Hong Yang Yan ◽  
Guo Qing Zeng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Composition ◽  
Chemical Etching ◽  
Etching Time ◽  
X Ray Diffraction ◽  
X Ray ◽  
Black Films ◽  
Surface Morphologies ◽  
Scanning Electron

Ni-P ultra-black films having conical pores with the diameter of ~ 10-30 μm and the depth of ~ 15-30 μm were prepared by chemical etching of electroless plated Ni-P films using 8 mol/L nitric acid at 40 °C for 60 s. The phase composition and microstructure of the film samples were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The results show that the diameter and depth of the etching pores become larger and the flat top regions bounded by etching pores become smaller by the coalescence of adjacent pores with the increase of etching time. The surface morphologies of the etched Ni-P films are characterized by the distribution of conical pores.

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