Slag movement on SiO2-based prism refractories in different slag systems was observed. The cross section shape evolution mechanism was discussed. Two types of shape evolution appear. For PbO-SiO2 slag whose surface te...Slag movement on SiO2-based prism refractories in different slag systems was observed. The cross section shape evolution mechanism was discussed. Two types of shape evolution appear. For PbO-SiO2 slag whose surface tension improves with SiO2 concentration, slag film flows up along four edges under axial Marangoni shear force and wettability. Then, it flows down along four lateral faces under gravity. Corrosion rate at edges is larger than that on lateral faces due to different SiO2 solubilities of ascending and descending flow. Prism cross section shape changes from square to round. For FetO-SiO2 slag whose surface tension reduces with the increase of SiO2 concentration, slag film flows up under the inflence of wettability. Then, it flows down under Marangoni shear force and gravity. Compared to four edges, slag is mainly up and down on four lateral faces due to larger surface tension and size. So, prism cross section shape keeps square.展开更多
A CuPc/SiO2 sample is fabricated. Its morphology is characterized by atomic force microscopy, and the electron states are investigated by X-ray photoelectron spectroscopy. In order to investigate these spectra in deta...A CuPc/SiO2 sample is fabricated. Its morphology is characterized by atomic force microscopy, and the electron states are investigated by X-ray photoelectron spectroscopy. In order to investigate these spectra in detail, all of these spectra are normalized to the height of the most intense peak,and each component is fitted with a single Gaussian function. Analysis shows that the O element has great bearing on the electron states and that SiO2 layers produced by spurting technology are better than those produced by oxidation technology.展开更多
Novel models (2× 1) of Si(001)-SiO2 interface structure have been established. The method of the first-principle General Gradient Approximation (GGA) is employed to structurally optimize the established the...Novel models (2× 1) of Si(001)-SiO2 interface structure have been established. The method of the first-principle General Gradient Approximation (GGA) is employed to structurally optimize the established theoretical models under the K-point space of periodic boundary condition. The structures after optimization have been analyzed, and the results show that the interfaces present in disordered state and both Si-O-Si and Si=O structures exist. Meanwhile, the bonding of surface structure is analyzed via the graphics of electron localization function(ELF).展开更多
The effects of dry O2post oxidation annealing(POA)at different temperatures on SiC/SiO2stacks are comparatively studied in this paper.The results show interface trap density(Dit)of SiC/SiO2stacks,leakage curr...The effects of dry O2post oxidation annealing(POA)at different temperatures on SiC/SiO2stacks are comparatively studied in this paper.The results show interface trap density(Dit)of SiC/SiO2stacks,leakage current density(Jg),and time-dependent dielectric breakdown(TDDB)characteristics of the oxide,are affected by POA temperature and are closely correlated.Specifically,Dit,Jg,and inverse median lifetime of TDDB have the same trend against POA temperature,which is instructive for SiC/SiO2interface quality improvement.Moreover,area dependence of TDDB characteristics for gate oxide on SiC shows different electrode areas lead to same slope of TDDB Weibull curves.展开更多
SiC/SiO2 nanochains were synthesized on a carbon fiber substrate by a catalyst-free thermal evaporation method in the Ar/CO atmosphere.X-ray diffraction(XRD),Fourier-transform infrared spectroscopy(FT-IR),scanning ele...SiC/SiO2 nanochains were synthesized on a carbon fiber substrate by a catalyst-free thermal evaporation method in the Ar/CO atmosphere.X-ray diffraction(XRD),Fourier-transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM)and transmission electron microscopy(TEM)revealed that the as-synthesized SiC/SiO2 nanochains are composed of single-crystalline SiC nanowires and amorphous SiO2 beads.The introduction of CO can promote the formation of SiO2,so that the SiC/SiO2 nanochains are subsequently formed during cooling.In addition,the photoluminescence spectrum of SiC/SiO2 nanochains showed a broad emission peak at around 350 nm,which is ascribed to the oxygen discrepancy in the SiO2 beads as well as the SiC/SiO2 interfacial effect.These findings can provide guidance for further study of the vapor growth of 1D SiC-based materials.展开更多
基金Projects(U1738101,51804023)supported by the National Natural Science Foundation of ChinaProjects(FRF-TP-18-007A1,FRF-MP-18-007)supported by Fundamental Research Funds for the Central Universities,ChinaProject(2019M650489)supported by China Postdoctoral Science Foundation
摘要Slag movement on SiO2-based prism refractories in different slag systems was observed. The cross section shape evolution mechanism was discussed. Two types of shape evolution appear. For PbO-SiO2 slag whose surface tension improves with SiO2 concentration, slag film flows up along four edges under axial Marangoni shear force and wettability. Then, it flows down along four lateral faces under gravity. Corrosion rate at edges is larger than that on lateral faces due to different SiO2 solubilities of ascending and descending flow. Prism cross section shape changes from square to round. For FetO-SiO2 slag whose surface tension reduces with the increase of SiO2 concentration, slag film flows up under the inflence of wettability. Then, it flows down under Marangoni shear force and gravity. Compared to four edges, slag is mainly up and down on four lateral faces due to larger surface tension and size. So, prism cross section shape keeps square.
摘要A CuPc/SiO2 sample is fabricated. Its morphology is characterized by atomic force microscopy, and the electron states are investigated by X-ray photoelectron spectroscopy. In order to investigate these spectra in detail, all of these spectra are normalized to the height of the most intense peak,and each component is fitted with a single Gaussian function. Analysis shows that the O element has great bearing on the electron states and that SiO2 layers produced by spurting technology are better than those produced by oxidation technology.
基金Supported by the National Grand Fundamental Research 973 Program of China (No. 51310Z07-3) and the Research Program of Application of Sichuan Department of Science and Technology (No. 02GY029-006)
摘要Novel models (2× 1) of Si(001)-SiO2 interface structure have been established. The method of the first-principle General Gradient Approximation (GGA) is employed to structurally optimize the established theoretical models under the K-point space of periodic boundary condition. The structures after optimization have been analyzed, and the results show that the interfaces present in disordered state and both Si-O-Si and Si=O structures exist. Meanwhile, the bonding of surface structure is analyzed via the graphics of electron localization function(ELF).
基金the General Program of the National Natural Science Foundation of China(Grant No.61974159)the Youth Innovation Promotion Association of the Chinese Academy of Sciences and Scientific Instrument Developing Project of the Chinese Academy of Sciences(Grant No.YJKYYQ20200039)。
摘要The effects of dry O2post oxidation annealing(POA)at different temperatures on SiC/SiO2stacks are comparatively studied in this paper.The results show interface trap density(Dit)of SiC/SiO2stacks,leakage current density(Jg),and time-dependent dielectric breakdown(TDDB)characteristics of the oxide,are affected by POA temperature and are closely correlated.Specifically,Dit,Jg,and inverse median lifetime of TDDB have the same trend against POA temperature,which is instructive for SiC/SiO2interface quality improvement.Moreover,area dependence of TDDB characteristics for gate oxide on SiC shows different electrode areas lead to same slope of TDDB Weibull curves.
基金Project(U19A2088)supported by the National Natural Science Foundation of ChinaProject(2019RS2058)supported by the Special Fund for Innovative Construction of Hunan Province,China。
摘要SiC/SiO2 nanochains were synthesized on a carbon fiber substrate by a catalyst-free thermal evaporation method in the Ar/CO atmosphere.X-ray diffraction(XRD),Fourier-transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM)and transmission electron microscopy(TEM)revealed that the as-synthesized SiC/SiO2 nanochains are composed of single-crystalline SiC nanowires and amorphous SiO2 beads.The introduction of CO can promote the formation of SiO2,so that the SiC/SiO2 nanochains are subsequently formed during cooling.In addition,the photoluminescence spectrum of SiC/SiO2 nanochains showed a broad emission peak at around 350 nm,which is ascribed to the oxygen discrepancy in the SiO2 beads as well as the SiC/SiO2 interfacial effect.These findings can provide guidance for further study of the vapor growth of 1D SiC-based materials.