Polycrystalline tungsten（W）and molybdenum（Mo）materials both non-annealed and annealed at temperatures of 800-1750~C have been irradiated with low-energy（220 eV）,high-flux（~10^（21）ions/m^2.s）He~＋at an irradi...Polycrystalline tungsten（W）and molybdenum（Mo）materials both non-annealed and annealed at temperatures of 800-1750~C have been irradiated with low-energy（220 eV）,high-flux（~10^（21）ions/m^2.s）He~＋at an irradiation temperature of 600℃and at a dose of1.0×10^（25）ions/m^2.This non-destructive conductive atomic force microscopy technique provides direct observation and comparison of surface swellings with growth of nanoscale defects in the irradiated materials.A coral-like surface structure and nanostructured defects were formed in W when irradiated at a He＋dose of 1.0×10^（25）ions/m^2.Increasing the annealing temperature resulted in an increase in the size of nanostructured defects and serious surface damage of W.Compared to W,Mo suffered much less surface damage after being irradiated at various He~＋doses.展开更多
Low-pressure dielectric barrier discharge（DBD） TiCl4/O2and N2 plasmas have been used to deposit titanium oxide films at different power supply driving frequencies. A homemade large area low pressure DBD reactor was ...Low-pressure dielectric barrier discharge（DBD） TiCl4/O2and N2 plasmas have been used to deposit titanium oxide films at different power supply driving frequencies. A homemade large area low pressure DBD reactor was applied, characterized by the simplicity of the experimental set-up and a low consumption of feed gas and electric power, as well as being easy to operate. Atomic force microscopy, scanning electron microscopy, energy dispersive spectroscopy,and contact angle measurements have been used to characterize the deposited films. Experimental results show all deposited films are uniform and hydrophilic with a contact angle of about 15 o.Compared to titanium oxide films deposited in TiCl4/O2gas mixtures, those in TiCl4/O2/N2gas mixtures are much more stable. The contact angle of titanium oxide films in TiCl4/O2/N2gas mixtures with the addition of 50% N2 and 20% TiCl4 is still smaller than 20 o, while that of undoped titanium oxide films is larger than 64 owhen they are measured after one week. The low-pressure TiCl4/O2plasmas consist of pulsed glow-like discharges with peak widths of several microseconds, which leads to the uniform deposition of titanium oxide films. Increasing a film thickness over several hundreds of nm leads to the film’s fragmentation due to the over-high film stress. Optical emission spectra（OES） of TiCl4/O2DBD plasmas at various power supply driving frequencies are presented.展开更多
基金supported by the National Magnetic Confinement Fusion Program of China(No.2011GB108011)National Natural Science Foundation of China(No.11405023)+1 种基金the Scientific Research Fund of Liaoning Provincial Education Department(No.L2014539)the Fundamental Research Funds for the Central Universities of China(No.DC201502080410)
文摘Polycrystalline tungsten（W）and molybdenum（Mo）materials both non-annealed and annealed at temperatures of 800-1750~C have been irradiated with low-energy（220 eV）,high-flux（~10^（21）ions/m^2.s）He~＋at an irradiation temperature of 600℃and at a dose of1.0×10^（25）ions/m^2.This non-destructive conductive atomic force microscopy technique provides direct observation and comparison of surface swellings with growth of nanoscale defects in the irradiated materials.A coral-like surface structure and nanostructured defects were formed in W when irradiated at a He＋dose of 1.0×10^（25）ions/m^2.Increasing the annealing temperature resulted in an increase in the size of nanostructured defects and serious surface damage of W.Compared to W,Mo suffered much less surface damage after being irradiated at various He~＋doses.
基金supported by National Natural Science Foundation of China(Nos.10875025 and 20803007)Fundamental Research Funds for Central Universities of China(Nos.DC12010116 and DC13010106)Program for Liaoning Excellent Talents in University(LJQ20l3128)
文摘Low-pressure dielectric barrier discharge（DBD） TiCl4/O2and N2 plasmas have been used to deposit titanium oxide films at different power supply driving frequencies. A homemade large area low pressure DBD reactor was applied, characterized by the simplicity of the experimental set-up and a low consumption of feed gas and electric power, as well as being easy to operate. Atomic force microscopy, scanning electron microscopy, energy dispersive spectroscopy,and contact angle measurements have been used to characterize the deposited films. Experimental results show all deposited films are uniform and hydrophilic with a contact angle of about 15 o.Compared to titanium oxide films deposited in TiCl4/O2gas mixtures, those in TiCl4/O2/N2gas mixtures are much more stable. The contact angle of titanium oxide films in TiCl4/O2/N2gas mixtures with the addition of 50% N2 and 20% TiCl4 is still smaller than 20 o, while that of undoped titanium oxide films is larger than 64 owhen they are measured after one week. The low-pressure TiCl4/O2plasmas consist of pulsed glow-like discharges with peak widths of several microseconds, which leads to the uniform deposition of titanium oxide films. Increasing a film thickness over several hundreds of nm leads to the film’s fragmentation due to the over-high film stress. Optical emission spectra（OES） of TiCl4/O2DBD plasmas at various power supply driving frequencies are presented.
