Preparation and growth mechanism of the flower-like whiskers of γ-, θ-, and α-Al2O3 phases by homogeneous precipitation/calcination method

2021 ◽  
Author(s):  
Jiangsheng Huang ◽  
Changlian Chen ◽  
Zhiliang Huang ◽  
Jiarui Fu ◽  
Shi Chen ◽  
...  
Keyword(s):  
Growth Mechanism ◽  
Homogeneous Precipitation ◽  
Calcination Method ◽  
Α Al2o3

Growth mechanism of single-crystal α-Al2O3 nanofibers fabricated by electrospinning techniques

2011 ◽  
Vol 31 (5) ◽  
pp. 723-731 ◽  
Author(s):  
Pei-Ching Yu ◽  
Rung-Je Yang ◽  
Yi-Yang Tsai ◽  
Wolfgang Sigmund ◽  
Fu-Su Yen
Keyword(s):  
Single Crystal ◽  
Growth Mechanism ◽  
Α Al2o3

Study on the Growth Mechanism of K2Ti4O9 Crystal

2018 ◽  
Vol 37 (5) ◽  
pp. 405-410
Author(s):  
Xuesong Zhou ◽  
Jing Fan ◽  
Xiaoli Wei ◽  
Yi Shen ◽  
Yanzhi Meng
Keyword(s):  
Electron Microscopy ◽  
Growth Mechanism ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Calcination Temperatures ◽  
Transmission Electron ◽  
Transformation Reaction ◽  
Calcination Method ◽  
Potassium Hexatitanate ◽  
Parallel Action

AbstractPotassium hexatitanate (K2Ti4O9) whiskers were prepared by the kneading–drying–calcination method. After the preparation of products under different calcination temperatures and holding times, their morphology and structure were characterized by thermogravimetric and differential thermal, X-ray diffraction (XRD), scanning electron microscopy and transmission electron microscopy. The XRD analysis showed that the reaction mixture was completely converted to K2Ti4O9 crystals at 800 °C when the T/K ratio was 3. Based on the analysis of LS (liquid–solid) growth mechanism, the corresponding transformation reaction mechanism during the roasting was elucidated. K2Ti4O9 whiskers grow mainly through the parallel action at a low temperature. With the increase in temperature, the series effect is obvious.

Growth morphology and growth mechanism of α-Al2O3 whiskers

1983 ◽  
Vol 61 (1) ◽  
pp. 75-79 ◽  
Author(s):  
M. Schreiner ◽  
W. Wruss ◽  
B. Lux
Keyword(s):  
Growth Mechanism ◽  
Growth Morphology ◽  
Α Al2o3

Nitridation effect of the α-Al2O3 substrates on the quality of the GaN films grown by pulsed laser deposition

RSC Advances ◽  
2014 ◽  
Vol 4 (75) ◽  
pp. 39651-39656 ◽  
Author(s):  
Wenliang Wang ◽  
Zuolian Liu ◽  
Weijia Yang ◽  
Yunhao Lin ◽  
Shizhong Zhou ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Growth Mechanism ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
High Quality ◽  
Α Al2o3

High-quality GaN films with sharp and abrupt interfaces have been achieved on nitrided α-Al2O3 substrates by pulsed laser deposition. The effect of nitridation on the properties and the growth mechanism of GaN films have been carefully studied.

Modification of Al2O3 Microfiltration Membrane by Nano-ZnO Coating

2007 ◽  
Vol 280-283 ◽  
pp. 1045-1048 ◽  
Author(s):  
Jianer Zhou ◽  
Jian Qing Wu ◽  
Yong Qing Wang ◽  
Wei Hui Jiang ◽  
Guang Hua Ma ◽  
...  
Keyword(s):  
Raw Materials ◽  
Zinc Nitrate ◽  
Precipitation Method ◽  
Homogeneous Precipitation ◽  
Test Results ◽  
Nano Zno ◽  
Microfiltration Membrane ◽  
Homogeneous Precipitation Method ◽  
Modified Membrane ◽  
Α Al2o3

In this paper, the α-Al2O3 microfiltration membrane modified by nano-ZnO coating was obtained using zinc nitrate and urea as raw materials via homogeneous precipitation method. The effects of reaction temperature and coating times on the modification of the membrane were emphatically studied. The test results show that the flux of modified membrane is raised by 43% when the nano-ZnO particles (5 ~ 10 nm) are smoothly and densely coated on the surface of the membrane. The mechanism of the modification was studied by means of TEM, FTIR, XPS, Zeta electric potential analyzer, etc.

Radiation-Induced Precipitation at Thin Foil Surfaces in Ni-Be Alloys

1982 ◽  
Vol 40 ◽  
pp. 598-599
Author(s):  
T. Mukai ◽  
T. E. Mitchell
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Electron Irradiation ◽  
High Vacuum ◽  
Thin Foil ◽  
Homogeneous Precipitation ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Radiation Induced

Radiation-induced homogeneous precipitation in Ni-Be alloys was recently observed by high voltage electron microscopy. A coupling of interstitial flux with solute Be atoms is responsible for the precipitation. The present investigation further shows that precipitation is also induced at thin foil surfaces by electron irradiation under a high vacuum.

Montmorillonite Dendrites

1974 ◽  
Vol 32 ◽  
pp. 454-455
Author(s):  
Necip Güven ◽  
Rodney W. Pease
Keyword(s):  
Crystal Growth ◽  
Growth Mechanism ◽  
Growth Front ◽  
Morphological Features ◽  
Dendritic Crystal ◽  
Crystal Growth Mechanism

Morphological features of montmorillonite aggregates in a large number of samples suggest that they may be formed by a dendritic crystal growth mechanism (i.e., tree-like growth by branching of a growth front).

Structural phenomena in the growth of carbon nanotubes

1993 ◽  
Vol 51 ◽  
pp. 750-751
Author(s):  
Jun Jiao
Keyword(s):  
Carbon Nanotubes ◽  
Growth Mechanism ◽  
Carbonaceous Material ◽  
Cluster Growth ◽  
Structural Elements ◽  
Rich Variety ◽  
Different Shapes ◽  
Point To Point

HREM studies of the carbonaceous material deposited on the cathode of a Huffman-Krätschmer arc reactor have shown a rich variety of multiple-walled nano-clusters of different shapes and forms. The preparation of the samples, as well as the variety of cluster shapes, including triangular, rhombohedral and pentagonal projections, are described elsewhere.The close registry imposed on the nanotubes, focuses attention on the cluster growth mechanism. The strict parallelism in the graphitic separation of the tube walls is maintained through changes of form and size, often leading to 180° turns, and accommodating neighboring clusters and defects. Iijima et. al. have proposed a growth scheme in terms of pentagonal and heptagonal defects and their combinations in a hexagonal graphitic matrix, the first bending the surface inward, and the second outward. We report here HREM observations that support Iijima’s suggestions, and add some new features that refine the interpretation of the growth mechanism. The structural elements of our observations are briefly summarized in the following four micrographs, taken in a Hitachi H-8100 TEM operating at an accelerating voltage of 200 kV and with a point-to-point resolution of 0.20 nm.

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