Epitaxial Growth of α-Fe2O3 Thin Films on c-Plane Sapphire Substrate by Hydrothermal Method

2011 ◽  
Vol 702-703 ◽  
pp. 999-1002 ◽  
Author(s):  
Song Li ◽  
Gao Wu Qin ◽  
Liang Zuo
Keyword(s):  
Thin Films ◽  
Gas Sensors ◽  
Sapphire Substrate ◽  
Electron Microscopic Observation ◽  
Interface Energy ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Scanning Electron Microscopic ◽  
Hydrolysis Of

Thin films of hematite find extensive applications in photoelectrochemistry, photocatalysis, and gas sensors. c-axis oriented hematite films have been directly grown on c-plane sapphire substrate using chemical method via hydrolysis of ferric cations. X-ray diffraction (XRD) reveals that the crystalline phases of the films and corresponding sediment produced in the solution were α-Fe2O3 and pure β-FeOOH, demonstrating the promotion of nucleation of hematite on sapphire substrate as a result of lowered interface energy. Phi-scan results indicate that the hematite films are grown with (0001) planes parallel to c-plane of Al2O3. Scanning electron microscopic observation shows that the hematite films are composed of pyramid-shaped nanocrystals with smooth surface facets.

scholarly journals Preparation of Reswellable Amorphous Porous Celluloses through Hydrogelation from Ionic Liquid Solutions

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3249 ◽  
Author(s):  
Satoshi Idenoue ◽  
Yoshitaka Oga ◽  
Daichi Hashimoto ◽  
Kazuya Yamamoto ◽  
Jun-ichi Kadokawa
Keyword(s):  
Mechanical Properties ◽  
Ionic Liquid ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Liquid Solutions ◽  
Scanning Electron Microscopic ◽  
Porous Morphology ◽  
Scanning Electron

In this study, we have performed the preparation of reswellable amorphous porous celluloses through regeneration from hydrogels. The cellulose hydrogels were first prepared from solutions with an ionic liquid, 1-butyl-3-methylimidazolium chloride (BMIMCl), in different concentrations. Lyophilization of the hydrogels efficiently produced the regenerated celluloses. The powder X-ray diffraction and scanning electron microscopic measurements of the products suggest an amorphous structure and porous morphology, respectively. Furthermore, the pore sizes of the regenerated celluloses, or in turn, the network sizes of cellulose chains in the hydrogels, were dependent on the concentrations of the initially prepared solutions with BMIMCl, which also affected the tensile mechanical properties. It was suggested that the dissolution states of the cellulose chains in the solutions were different, in accordance with the concentrations, which representatively dominated the pore and network sizes of the above materials. When the porous celluloses were immersed in water, reswelling was observed to regenerate the hydrogels.

Preparation of AlN thin films by means of CVD using iodide source under atmospheric pressure

2007 ◽  
Vol 1040 ◽  
Author(s):  
Hiroki Iwane ◽  
Naoki Wakiya ◽  
Naonori Sakamoto ◽  
Takato Nakamura ◽  
Hisao Suzuki
Keyword(s):  
Thin Films ◽  
Residual Stress ◽  
Sapphire Substrate ◽  
Atmospheric Pressure ◽  
Chemical Vapor ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Aluminum Iodide

AbstractEpitaxial aluminum nitride (AlN) thin films were successfully prepared on the (0001) sapphire substrate by chemical vapor deposition (CVD) using aluminum iodide (AlI3) and ammonia (NH3) under atmospheric pressure at 750 ºC. The crystallographic relationship between AlN thin films and Al2O3 substrate is in the following; AlN(0001)//Al2O3(0001) and AlN[1010]//Al2O3[1120]. Lattice parameters of AlN thin film measured by X-ray diffraction revealed that c=0.498 and a=0.311 nm, respectively. Residual stress estimated by modified sin2ψ method was 0.38 GPa in compressive stress. Cross-sectional TEM observation revealed that an interlayer lies between the AlN films and the sapphire substrate. It was suggested that relaxation of residual stress caused by the mismatching of lattice parameter and thermal expansion coefficient was brought about by the interlayer.

scholarly journals Influence of the type of electrolyte on the morphological and crystallographic characteristics of lead powder particles

2013 ◽  
Vol 78 (9) ◽  
pp. 1387-1395 ◽  
Author(s):  
Nebojsa Nikolic ◽  
Vesna Maksimovic ◽  
Goran Brankovic ◽  
Predrag Zivkovic ◽  
Miomir Pavlovic
Keyword(s):  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Lead Powder ◽  
Scanning Electron Microscopic ◽  
Crystallographic Characteristics ◽  
Powder Particles ◽  
Primary Type ◽  
Secondary Type ◽  
Scanning Electron

Lead electrodeposition processes from the basic (nitrate) and complex (acetate) electrolytes were mutually compared by the scanning electron microscopic and the X-ray diffraction analysis of the produced powder particles. The shape of dendritic particles strongly depended on the type of electrolyte. The dendrites composed of stalk and weakly developed primary branches (the primary type) were predominantly formed from the basic electrolyte. The ramified dendrites composed of stalk and of both primary and secondary branches (the secondary type) were mainly formed from the complex electrolyte. In the both type of powder particles Pb crystallites were predominantly oriented in the (111) plane. Formation of powder particles of the different shape with the strong (111) preferred orientation was discussed and explained by the consideration of the general characteristics of the growth of a crystal in the electrocrystallization processes.

Characterization on Aggregating Structure of Aloe Extract Crosslinked Cotton Fabric

2011 ◽  
Vol 311-313 ◽  
pp. 1132-1135 ◽  
Author(s):  
Yun Hui Xu ◽  
Li Chen
Keyword(s):  
Citric Acid ◽  
Cotton Fabric ◽  
Cotton Textile ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Scanning Electron Microscopic ◽  
Ft Ir ◽  
Textile Products

For exploiting the multifunctional ecological cotton textile products and developing the green modified technology for cotton fabrics, a novel cotton fabric with aloe extract crosslinking was prepared using citric acid as a crosslink agent under the pad-dry-cure procedure. Scanning electron microscopic photographs showed that the modification with aloe extract occurred on the surface of cotton fabric. FT-IR spectra of the modified fabric illuminated that aloe extract crosslinked with cotton fabric through the bridge linkage of citric acid after a series of reaction. The wide angle X-ray diffraction analysis indicated that the crystallinity of aloe extract modified cotton fabric slightly decreased. Furthermore, the changes in the aggregating structure and crystallinity were also reflected in the mechanical property studies of these modified fabrics. After treatment by aloe extract, the breaking strength and elongation of cotton fabric decreased. However, the moisture regain of the modified cotton fabric increased. The results obtained are useful in explaining structure-property correlations with respect to the aggregating structure and crystallinity, and suggest valuable information in planning applications for the aloe extract modified cotton textile products.

Fabrication of SnS2 Flower Like Nanoflake Assemblies Through Thermal Evaporation

2007 ◽  
Vol 7 (12) ◽  
pp. 4540-4545 ◽  
Author(s):  
Subhajit Biswas ◽  
Soumitra Kar ◽  
Tandra Ghoshal ◽  
Subhadra Chaudhuri
Keyword(s):  
Thermal Evaporation ◽  
Growth Direction ◽  
Vapor Concentration ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Transmission Electron ◽  
Scanning Electron Microscopic ◽  
The Individual

Uniform as well as flower like patterns of SnS2 nanoflakes were produced by a thermal evaporation process. Interpenetrating phenomenon was observed between the individual nanoflakes during the course of their lateral growth. The interpenetrating growth and controlled vapor concentration as well as the substrate temperature leads to the formation of flower like assemblies of SnS2 nanoflakes. Morphology and growth mechanism of the nanostructures were studied by scanning electron microscopic observations at different stages of the nanoflake growth. The produced nanoflakes were characterized by X-ray diffraction, scanning and transmission electron microscopy, and Raman spectroscopic measurements. SnS2 nanoflakes were perfectly single crystalline and growth direction of the nanoflakes was along the {101}-lattice plane.

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