High-Quality Graphene as a Coating for Polycrystalline Tungsten in Low-Energy Helium and Deuterium Plasma Exposures

2021 ◽  
pp. 152979
Author(s):  
Marcos Navarro ◽  
Marziyeh Zamiri ◽  
RB Jacobson ◽  
Russ Doerner ◽  
John Santarius ◽  
...  
2021 ◽  
Vol 11 (4) ◽  
pp. 1619
Author(s):  
Jing Yan ◽  
Xia Li ◽  
Kaigui Zhu

The surface morphology of pure W bulks and nanocrystalline tungsten films was investigated after exposure to a low-energy (100 eV/D), high-flux (1.8 × 1021 D·m−2s−1) deuterium plasma. Nanocrystalline tungsten films of 6 μm thickness were deposited on tungsten bulks and exposed to deuterium plasma at various fluences ranging from 1.30 × 1025 to 5.18 × 1025 D·m−2. Changes in surface morphology from before to after irradiation were studied with scanning electron microscopy (SEM). The W bulk exposed to low-fluence plasma (1.30 × 1025 D·m−2) shows blisters. The blisters on the W bulk irradiated to higher-fluence plasma are much larger (~2 µm). The blisters on the surface of W films are smaller in size and lower in density than those of the W bulks. In addition, the modifications exhibit the appearance of cracks below the surface after deuterium plasma irradiation. It is suggested that the blisters are caused by the diffusion and aggregation of the deuterium-vacancy clusters. The deuterium retention of the W bulks and nanocrystalline tungsten films was studied using thermal desorption spectroscopy (TDS). The retention of deuterium in W bulks and W films increases with increasing deuterium plasma fluence when irradiated at 500 K.


1989 ◽  
Vol 145 ◽  
Author(s):  
H. Temkin ◽  
L. R. Harriott ◽  
J. Weiner ◽  
R. A. Hamm ◽  
M. B. Panish

AbstractWe demonstrate a vacuum lithography process which uses a finely focused Ga ion beam to write the pattern which is then transferred to the InP pattern by low energy dry etching. Surface steps on the order of 1000-2000A in height, and lateral resolution limited only by size of the ion beam, can be efficiently prepared using moderate Ga ion fluences. The surfaces prepared by this process are damage free and suitable for epitaxial overgrowth. GaInAs/InP heterostructures grown on in-situ patterned substrates show excellent morphology and high luminescence efficiency.


2017 ◽  
Vol 897 ◽  
pp. 375-378 ◽  
Author(s):  
Satoshi Torimi ◽  
Koji Ashida ◽  
Norihito Yabuki ◽  
Masato Shinohara ◽  
Takuya Sakaguchi ◽  
...  

As a new thinning and surface planarizing process of Silicon Carbide (SiC) wafer, we propose the completely thermal-chemical etching process; Si-vapor etching (Si-VE) technology. In this work, the effects of mechanical strength and surface step-terrace structure by Si-VE are investigated on the 4° off-axis 4H-SiC (0001) Si-face substrates. The indentation hardness of Si-VE surface is superior to the conventional chemo-mechanical polishing (CMP) surface even after epitaxial growth. The transverse strength of thinned Si-VE substrate is also superior to the conventional mechanically ground substrate. The surface step-terrace structures are observed by the low energy electron channeling contrast (LE-ECC) imaging technique. The latent scratch causes bunched step lines (BSLs) with various inhomogeneous step morphologies only on the CMP surface.


2017 ◽  
Vol 125 ◽  
pp. 473-478 ◽  
Author(s):  
Wangguo Guo ◽  
Long Cheng ◽  
Jun Wang ◽  
Qingwei Fu ◽  
Shaoyang Qin ◽  
...  

2019 ◽  
Vol 148 ◽  
pp. 111267 ◽  
Author(s):  
Hao-Dong Liu ◽  
Hai-Shan Zhou ◽  
Lu Wang ◽  
Yu-Ping Xu ◽  
Feng Liu ◽  
...  
Keyword(s):  

2016 ◽  
Vol 56 (3) ◽  
pp. 036010 ◽  
Author(s):  
Xiu-Li Zhu ◽  
Ying Zhang ◽  
Long Cheng ◽  
Yue Yuan ◽  
Gregory De Temmerman ◽  
...  

Author(s):  
V. S. M. Pereira ◽  
S. Wang ◽  
T. Morgan ◽  
H. Schut ◽  
J. Sietsma

AbstractIn the present work, an ODS 12 Cr steel was characterized using Electron Microscopy techniques, in an as-received condition and after annealing treatments between 773 K and 1573 K. Results show a complex microstructure, with the presence of fine Y–Ti–O nanoparticles dispersed in the matrix. After annealing at 1573 K, the average diameter of Y–Ti–O nanoparticles increases from ~ 4 to ~ 7 nm and partial recrystallization occurs. The trapping behavior of deuterium in the steel in its as-received state and annealed at 1573 K was investigated. Samples were exposed to low-energy deuterium plasma and analyzed with thermal desorption spectroscopy, after waiting times of 1 day and 25 days. The samples measured 1 day after exposure released a higher total amount of deuterium than the ones measured after 25 days. The effect of waiting time is explained by the release of deuterium, at 300 K, from sites with low activation energy for detrapping, Ed. In the as-received condition, part of the deuterium detrapped at 300 K was re-trapped by high-Ed sites. For the samples in the annealed condition, the redistribution of deuterium from low-Ed to high-Ed sites was not observed, but the total amount of deuterium released was higher.


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