Tungsten oxide thin films were deposited on glass substrates by the magnetron sputtering of WO3 bulk at room temperature. The deposited films were annealed at different temperatures in air. The structural measurements...Tungsten oxide thin films were deposited on glass substrates by the magnetron sputtering of WO3 bulk at room temperature. The deposited films were annealed at different temperatures in air. The structural measurements indicate that the films annealed below 300℃ were amorphous, while the films annealed at 400 ℃ were mixed crystalline with hexagonal and triclinic phases of WO3. It was observed that the crystallization of the annealed films becomes more and more distinct with an increase in the annealing temperature. At 400 ℃, nanorod-like structures were observed on the film surface when the annealing time was increased from 60 min to 180 min. The presence of W=O stretching, W-O-W stretching, W-O-W bending and various lattice vibration modes were observed in Raman measurements. The optical absorption behaviors of the films in the range of 450-800 nm are very different with changing annealing temperatures from the room temperature to 400 ℃. After annealing at 400 ℃, the film becomes almost transparent. Increasing annealing time at 400 ℃ can lead to a small blue shift of the optical gap of the film.展开更多
By means of ultrasonic attenuation apparatus, the ultrasonic velocity and attenuation ofanhydride-cured epoxy resins (EP)/poly (ethylene oxide) (PEO) blends were measured on thebasis of pulse-echo method. It was found...By means of ultrasonic attenuation apparatus, the ultrasonic velocity and attenuation ofanhydride-cured epoxy resins (EP)/poly (ethylene oxide) (PEO) blends were measured on thebasis of pulse-echo method. It was found that the sonic velocity of the blends decreased as thetemperature increased, but attenuation coefficient increased and possessed a peak value. Largervelocity and smaller attenuation coefficient(α)can be obtained from perfect crosslinking networkstructures of pure DGEBA cured with phthalic anhydride(PA). As for cured DGEBA/PEO blendsystems,sonic velocity decreased as a function of PEO concentration,but attenuation coefficient(α) increased.展开更多
A series of ethylene oxide-ethylene terephthalate segmented copolymers (EOET) weresynthesized and complexed with LiClO_4 to form some new polymer electrolytes. The EOET-LiClO_4 electrolytes exhibit not only high ionic...A series of ethylene oxide-ethylene terephthalate segmented copolymers (EOET) weresynthesized and complexed with LiClO_4 to form some new polymer electrolytes. The EOET-LiClO_4 electrolytes exhibit not only high ionic conductivity, but also good mechanical strengthand toughness. The EOET 3400--25--LiClO_4 complex possesses the highest conductivity (4. 65×10^(-5)s·cm^(-1) at room temperature when the ratio [Li^+]/[EO] equals 1/16. The structures of these electrolytes were examined with FTIR analysis, X-ray diffractionand DSC thermograms, and the results of high ionic conductivity of the segmented copolymerswere discussed.展开更多
The reconstruction process of the Si(111)√3 ×√3 R30°-Ag surface is studied by using a scanning tunnelling microscope at 78K.By applying a strong interaction between the tip and the surface,a tip-induced re...The reconstruction process of the Si(111)√3 ×√3 R30°-Ag surface is studied by using a scanning tunnelling microscope at 78K.By applying a strong interaction between the tip and the surface,a tip-induced reconstruction corresponding to the mergence of two Si(111)√3 ×√3 R30°-Ag domains is observed.Based on the inequivalent trimers(IET)model,this reconstruction process is attributed to a transition between the clockwise and counterclockwise IET domains.With this transition,the honeycomb-chained-trimer Si(111)√3 ×√3 R30°-Ag anti-phase boundary disappears and changes to the IET structure.展开更多
The in situ direct-current conductance behaviors of Cu/C_(60) nano-scale granular films have been investigated experimentally.The results show that the incorporation of Cu into Ceo greatly increases the conductance of...The in situ direct-current conductance behaviors of Cu/C_(60) nano-scale granular films have been investigated experimentally.The results show that the incorporation of Cu into Ceo greatly increases the conductance of the film.The orientational phase transition that exists in pure C_(60) single crystals still retains in the Cu/C_(60) co-evaporated Elms,while the transition temperature range is significantly widened.The interactions between the nano-scale Cu clusters and C_(60) grains are discussed.展开更多
C_(60) single crystals oriented at[111]about 1μm in size,were grown in C_(60) film on NaCl(001)substrate.Bilayer films of nickel,gold,silver,and indium over C_(60) on NaCl substrate prepared by vacuum deposition meth...C_(60) single crystals oriented at[111]about 1μm in size,were grown in C_(60) film on NaCl(001)substrate.Bilayer films of nickel,gold,silver,and indium over C_(60) on NaCl substrate prepared by vacuum deposition method were studied with a transmission electron microscope.It was found that for different kinds of metals,their nucleation and growth characteristics on C_(60) (111)surface are quite different.This phenomenon is mainly attributed to different activation energies of the four metals.Analyses of the experimental results indicate that the activation energies of Ni,Au,Ag,and In adatoms on C_(60) (111)surface change in a descent order.展开更多
SiOx （x = 0-2） films were deposited on BK-7 substrates by a low frequency reactive magnetron sputtering system with the oxygen flow rate （OFR） changing from 0 to 30 sccm. The samples were characterized by atomic f...SiOx （x = 0-2） films were deposited on BK-7 substrates by a low frequency reactive magnetron sputtering system with the oxygen flow rate （OFR） changing from 0 to 30 sccm. The samples were characterized by atomic force microscopy, spectrophotometer, and X-ray photoelectron spectroscopy. The extinction coefficient and refractive index decrease, while the optical transmittance increases with the increase of OFR from 0 to 17 sccm. The root mean square surface roughness has a maximum at 10 sccm OFR. The highest deposition rate is at 15 sccm OFR. Our results show that the films deposited at 20 sccm OFR are stoichiometric silica with relatively high deposition rate, low extinction coefficient, and low surface roughness. Therefore, a precise control of OFR is very important to obtain high quality films for optical applications.展开更多
Surface morphologies and microstructures of C 60 /Ag composite films were studied by atomic force microscope (AFM) and transmission electron microscope (TEM). The surface roughness depended on the substrate temperatur...Surface morphologies and microstructures of C 60 /Ag composite films were studied by atomic force microscope (AFM) and transmission electron microscope (TEM). The surface roughness depended on the substrate temperature, and the transition of surface morphology of rough→smooth→rough was observed when the substrate temperature increased from -50 to 120℃. Although the rms values are similar, the scaling properties of the thermal roughing and the kinetic roughing surfaces are quite different. The relations between the scaling properties, microstructures and roughing mechanisms are discussed based on the AFM and TEM results.展开更多
基金supported by the Young Scientists Fund of the National Natural Science Foundation of China(Grant Nos.11104365 and 11104366)the Hubei Key Laboratory of Low Dimensional Optoelectronic Material and Devices,China(Grant No.13XKL02002)
文摘Tungsten oxide thin films were deposited on glass substrates by the magnetron sputtering of WO3 bulk at room temperature. The deposited films were annealed at different temperatures in air. The structural measurements indicate that the films annealed below 300℃ were amorphous, while the films annealed at 400 ℃ were mixed crystalline with hexagonal and triclinic phases of WO3. It was observed that the crystallization of the annealed films becomes more and more distinct with an increase in the annealing temperature. At 400 ℃, nanorod-like structures were observed on the film surface when the annealing time was increased from 60 min to 180 min. The presence of W=O stretching, W-O-W stretching, W-O-W bending and various lattice vibration modes were observed in Raman measurements. The optical absorption behaviors of the films in the range of 450-800 nm are very different with changing annealing temperatures from the room temperature to 400 ℃. After annealing at 400 ℃, the film becomes almost transparent. Increasing annealing time at 400 ℃ can lead to a small blue shift of the optical gap of the film.
文摘By means of ultrasonic attenuation apparatus, the ultrasonic velocity and attenuation ofanhydride-cured epoxy resins (EP)/poly (ethylene oxide) (PEO) blends were measured on thebasis of pulse-echo method. It was found that the sonic velocity of the blends decreased as thetemperature increased, but attenuation coefficient increased and possessed a peak value. Largervelocity and smaller attenuation coefficient(α)can be obtained from perfect crosslinking networkstructures of pure DGEBA cured with phthalic anhydride(PA). As for cured DGEBA/PEO blendsystems,sonic velocity decreased as a function of PEO concentration,but attenuation coefficient(α) increased.
文摘A series of ethylene oxide-ethylene terephthalate segmented copolymers (EOET) weresynthesized and complexed with LiClO_4 to form some new polymer electrolytes. The EOET-LiClO_4 electrolytes exhibit not only high ionic conductivity, but also good mechanical strengthand toughness. The EOET 3400--25--LiClO_4 complex possesses the highest conductivity (4. 65×10^(-5)s·cm^(-1) at room temperature when the ratio [Li^+]/[EO] equals 1/16. The structures of these electrolytes were examined with FTIR analysis, X-ray diffractionand DSC thermograms, and the results of high ionic conductivity of the segmented copolymerswere discussed.
基金Supported by the National Natural Science Foundation of China under Grant Nos.5997203 and G1999075305the Hong Kong'Qiu Shi'Foundation.
文摘The reconstruction process of the Si(111)√3 ×√3 R30°-Ag surface is studied by using a scanning tunnelling microscope at 78K.By applying a strong interaction between the tip and the surface,a tip-induced reconstruction corresponding to the mergence of two Si(111)√3 ×√3 R30°-Ag domains is observed.Based on the inequivalent trimers(IET)model,this reconstruction process is attributed to a transition between the clockwise and counterclockwise IET domains.With this transition,the honeycomb-chained-trimer Si(111)√3 ×√3 R30°-Ag anti-phase boundary disappears and changes to the IET structure.
基金Supported by the National Natural Science Foundation of China under Grant Nos.59529204 and 19734002.
文摘The in situ direct-current conductance behaviors of Cu/C_(60) nano-scale granular films have been investigated experimentally.The results show that the incorporation of Cu into Ceo greatly increases the conductance of the film.The orientational phase transition that exists in pure C_(60) single crystals still retains in the Cu/C_(60) co-evaporated Elms,while the transition temperature range is significantly widened.The interactions between the nano-scale Cu clusters and C_(60) grains are discussed.
基金Supported by the National Natural Science Foundation of China under Grant Nos.59529204,19734002。
文摘C_(60) single crystals oriented at[111]about 1μm in size,were grown in C_(60) film on NaCl(001)substrate.Bilayer films of nickel,gold,silver,and indium over C_(60) on NaCl substrate prepared by vacuum deposition method were studied with a transmission electron microscope.It was found that for different kinds of metals,their nucleation and growth characteristics on C_(60) (111)surface are quite different.This phenomenon is mainly attributed to different activation energies of the four metals.Analyses of the experimental results indicate that the activation energies of Ni,Au,Ag,and In adatoms on C_(60) (111)surface change in a descent order.
基金This work was supported by the National Natural Sci-ence Foundation of China under Grant No. 50121202and 10174073
文摘SiOx （x = 0-2） films were deposited on BK-7 substrates by a low frequency reactive magnetron sputtering system with the oxygen flow rate （OFR） changing from 0 to 30 sccm. The samples were characterized by atomic force microscopy, spectrophotometer, and X-ray photoelectron spectroscopy. The extinction coefficient and refractive index decrease, while the optical transmittance increases with the increase of OFR from 0 to 17 sccm. The root mean square surface roughness has a maximum at 10 sccm OFR. The highest deposition rate is at 15 sccm OFR. Our results show that the films deposited at 20 sccm OFR are stoichiometric silica with relatively high deposition rate, low extinction coefficient, and low surface roughness. Therefore, a precise control of OFR is very important to obtain high quality films for optical applications.
文摘Surface morphologies and microstructures of C 60 /Ag composite films were studied by atomic force microscope (AFM) and transmission electron microscope (TEM). The surface roughness depended on the substrate temperature, and the transition of surface morphology of rough→smooth→rough was observed when the substrate temperature increased from -50 to 120℃. Although the rms values are similar, the scaling properties of the thermal roughing and the kinetic roughing surfaces are quite different. The relations between the scaling properties, microstructures and roughing mechanisms are discussed based on the AFM and TEM results.
