Polysilicon gate etching in high density plasmas. II. X-ray photoelectron spectroscopy investigation of silicon trenches etched using a chlorine-based chemistry

Author(s):  
F. H. Bell
Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 421
Author(s):  
Binwei Zheng ◽  
Weiwei Zhang ◽  
Litao Guan ◽  
Jin Gu ◽  
Dengyun Tu ◽  
...  

A high strength recycled newspaper (NP)/high density polyethylene (HDPE) laminated composite was developed using NP laminas as reinforcement and HDPE film as matrix. Herein, NP fiber was modified with stearic acid (SA) to enhance the water resistance of the NP laminas and NP/HDPE composite. The effects of heat treatment and SA concentration on the water resistance and tensile property of NP and composite samples were investigated. The chemical structure of the NP was characterized with X-ray diffractometer, X-ray photoelectron spectroscopy and attenuated total reflectance Fourier transform infrared spectra techniques. The surface and microstructure of the NP sheets were observed by scanning electron microscopy. An expected high-water resistance of NP sheets was achieved due to a chemical bonding that low surface energy SA were grafted onto the modified NP fibers. Results showed that the hydrophobicity of NP increased with increasing the stearic acid concentration. The water resistance of the composite laminates was depended on the hydrophobicity of the NP sheets. The lowest value of 2 h water absorption rate (3.3% ± 0.3%) and thickness swelling rate (2.2% ± 0.4%) of composite were obtained when the SA concentration was 0.15 M. In addition, the introduction of SA can not only enhance the water resistance of the composite laminates, but also reduce the loss of tensile strength in wet conditions, which shows potential in outdoor applications.


2012 ◽  
Vol 465 ◽  
pp. 276-282
Author(s):  
Zhong Hui Gao ◽  
Zhen Duo Cui ◽  
Xian Jin Yang

Pt nanoparticles were successfully assembled in self-organized TiO2 nanotubes by a chemical deposition method. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were used for characterizing the surface morphology and phase composition. Photocurrent response activity was measured. Different morphology of Pt-TiO2 NTs exhibited different photocurrent generation efficiency. High density Pt nanoparticles depositing on TiO2 NTs decreased the photocurrent of Pt-TiO2 electrodes. It was because the high density Pt nanoparticles could become the recombination centers of photoelectrons and holes.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shuo Zhao ◽  
Yuying Wu ◽  
Bo Zhou ◽  
Xiangfa Liu

AbstractBoron has a tendency to form bulk structures due to its unique electron-deficient property, so it’s hard for boron to form sheets in large quantities. Here, we report a novel method for the preparation of boron nanosheets in large quantities by copper medium. The method mainly includes mechanical exfoliation, recombination and extraction. A large number of boron nanosheets with a height of below 6 nm have been prepared in this work. X-ray photoelectron spectroscopy and Raman spectroscopy results confirmed that the nanosheets possess the characteristics of α-rhombohedra boron and β-rhombohedra boron with a high content of boron. Hexagonal and rhombic sheets have been observed and two different growth processes are revealed successfully, which are also the basic structures of boron nanosheets. An interesting phenomenon also have been discovered that high density nanotwins exist in β-Rhombohedra boron sheets and it might stimulate more interest in growth of nanomaterials.


Author(s):  
Yan Liu ◽  
Chongwei An ◽  
Jin Luo ◽  
Jingyu Wang

The main challenge for achieving better energetic materials is to increase their density. In this paper, cocrystals of HNIW (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane, often referred to as CL-20) with TNT (2,4,6-trinitrotoluene) were synthesized using ethanol in a green chemical method. The cocrystal was formulated as C13H11N15O18 and possesses a higher density (1.934 g cm−3) than published previously (1.846 g cm−3). This high-density cocrystal possesses a new structure, which can be substantiated by the different types of hydrogen bonds. The predominant driving forces that connect HNIW with TNT in the new cocrystal were studied at ambient conditions using single-crystal X-ray diffraction, powder X-ray diffraction, Fourier transform–infrared spectroscopy and Raman spectroscopy. The results reveal that the structure of the new HNIW/TNT cocrystals consists of three one-dimensional hydrogen-bonded chains exploiting the familiar HNIW–TNT multi-component supramolecular structure, in which two hydrogen-bonded chains are between —NO2 (HNIW) and —CH (TNT), and one hydrogen-bonded chain is between —CH (HNIW) and —NO2 (TNT). The changes to the electron binding energy and type of element in the new cocrystal were traced using X-ray photoelectron spectroscopy. Meanwhile, the physicochemical characteristics alter after cocrystallization due to the hydrogen bonding. It was found that the new HNIW/TNT cocrystal is more thermodynamically stable than HNIW. Thermodynamic aspects of new cocrystal decomposition are investigated in order to explain this observation. The detonation velocity of new HNIW/TNT cocrystals is 8631 m s−1, close to that of HNIW, whereas the mechanical sensitivity is lower than HNIW.


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