Total dose effects and single event effects on radiation-hardened power vertical double-diffusion metal oxide semiconductor（VDMOS） devices with composite SiO2-Si3N4 film gates are investigated.The relationships amon...Total dose effects and single event effects on radiation-hardened power vertical double-diffusion metal oxide semiconductor（VDMOS） devices with composite SiO2-Si3N4 film gates are investigated.The relationships among the important electrical parameters of the samples with different thickness SiO2-Si3N4 films,such as threshold voltage,breakdown voltage,and on-state resistance in accumulated dose,are discussed.The total dose experiment results show that the breakdown voltage and the on-state resistance barely change with the accumulated dose.However,the relationships between the threshold voltages of the samples and the accumulated dose are more complex,and not only positively drift,but also negatively drift.At the end of the total dose experiment,we select the group of samples which have the smaller threshold voltage shift to carry out the single event effect studies.We find that the samples with appropriate thickness ratio SiO2-Si3N4 films have a good radiation-hardening ability.This method may be useful in solving both the SEGR and the total dose problems with the composite SiO2-Si3N4 films.展开更多
In the present work, structure changes during （SiO2） composites have been investigated systematically stretching of isotactic polypropylene （iPP） and iPP/silicon dioxide The or-form crystal structure of both iPP a...In the present work, structure changes during （SiO2） composites have been investigated systematically stretching of isotactic polypropylene （iPP） and iPP/silicon dioxide The or-form crystal structure of both iPP and iPP/SiO2 composites is destroyed and transforms into the mesophase as the samples are stretched at a low temperature （35℃）, while stretching at high temperatures （90℃ and 120℃） can restrain the appearance of defects and keep the perfection of crystal structure. FTIR results reveal that the stretching temperatures show no obvious difference of the effect on the orientation of pure iPP, however, the orientation of iPP/SiO2 composites is greatly changed by the tensile temperature. In the case of micron-sized SiO2 particles （average particle diameter d 〉 1 μm）, the orientation of the composites is lower than that of pure iPP at all stretching temperatures. The above results suggest that the stretching temperature and the SiO2 particle size have great influence on the structure variation and orientation behavior of iPP/SiO2 composites.展开更多
Nano metal-particle dispersed glasses are the attractive candidates for nonlinear optical material applications. Au/SiO2 nano-composite thin films with 3 vol% to 65 vol% Au are prepared by inductively coupled plasma s...Nano metal-particle dispersed glasses are the attractive candidates for nonlinear optical material applications. Au/SiO2 nano-composite thin films with 3 vol% to 65 vol% Au are prepared by inductively coupled plasma sputtering. Au particles as perfect spheres with diameters between 10 nm and 30 nm are uniformly dispersed in the SiO2 matrix. Optical absorption peaks due to the surface plasmon resonance of Au particles are observed. The absorption property is enhanced with the increase of Au content, showing a maximum value in the films with 37 vol% Au. The absorption curves of the Au/SiO2 thin films with 3 vol% to 37 vol% Au accord well with the theoretical optical absorption spectra obtained from Mie resonance theory. Increasing Au content over 37 vol% results in the partial connection of Au particles, whereby the intensity of the absorption peak is weakened and ultimately replaced by the optical absorption of the bulk. The band gap decreases with Au content increasing from 3 vol% to 37 vol % but increases as Au content further increases.展开更多
The Ni-P/TiO2 composite film on sintered NdFeB permanent magnet was investigated by X-ray diffraction （XRD）,environmental scanning electron microscopy （ESEM）,and energy dispersive X-ray spectrometer （EDX）. The c...The Ni-P/TiO2 composite film on sintered NdFeB permanent magnet was investigated by X-ray diffraction （XRD）,environmental scanning electron microscopy （ESEM）,and energy dispersive X-ray spectrometer （EDX）. The corrosion resistance of Ni-P/TiO2 film coated on NdFeB magnet,in 0.5 mol/L NaCl solution,was studied by potentiodynamic polarization,salt spray test and electrochemical impedance spectroscopy （EIS） techniques. The self-corrosion current density （icorr） and the polarization resistance （Rp） of Ni-P/TiO2 film are 0.22 μA/cm2 （about 14% of that of Ni-P coating）,and 120 kΩ·cm2 （about 2 times of that of Ni-P coating）,respectively. The anti-salt spray time of Ni-P/TiO2 film is about 2.5 times of that of the Ni-P coating. The results indicate that Ni-P/TiO2 film has a better corrosion resistance than Ni-P coating,and the composite film increases the corrosion resistance of NdFeB magnet markedly.展开更多
ZrO2/TiO2 composite photocatalytic film was produced on the pure titanium substrate using in-situ Zr（OH）4 colloidal particle by the micro-arc oxidation technique and characterized by scanning electron microscope （...ZrO2/TiO2 composite photocatalytic film was produced on the pure titanium substrate using in-situ Zr（OH）4 colloidal particle by the micro-arc oxidation technique and characterized by scanning electron microscope （SEM）, energy dispersive X-ray （EDX）, X-ray diffraction （XRD） and ultraviolet-visible （UV-Vis） spectrophotometer. The composite film shows a lamellar and porous structure which consists of anatase, futile and ZrO2 phases. The optical absorption edge of film is shifted to longer wavelength when ZrO2 is introduced to TiO2. Furthermore, the photocatalytic reaction rate constants of degradation of rhodamine B solution with ZrO2/TiO2 composite film and pure TiO2 film under ultraviolet irradiation are measured as 0.0442 and 0.0186 h 1, respectively.展开更多
Cu2O/TiOa/Pt three-layer films were deposited on glass substrates using magnetron sputtering method. The surface morphology and the optical properties of the composite film were characterized by X-ray diffraction （XR...Cu2O/TiOa/Pt three-layer films were deposited on glass substrates using magnetron sputtering method. The surface morphology and the optical properties of the composite film were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, ultraviolet- visible spectroscopy （UV-Vis） and photoluminescence spectroscopy （PL）. The photocatalytic activity of the samples was evaluated by the photocatalytic degradation of methyl orange （MO） aqueous solution under visible light irradiation. The results indicate that the Cu2O/TiO2/Pt composite films are made up of three layers which are Pt layer, anatase-TiO2 layer and Cu2O layer from bottom to top. The surface of the films is even and composed of regular-shaped spherical particles. The photocatalytic activity of the Cu2O/TiO2/Pt three-layer film is much higher than that of the Cu2O/TiO2 double-layer film. Such enhancement is ascribed to the presence of Pt layer, which further inhibits the photogenerated electron-hole recombination, prolongs the lifetime of the photogenerated carriers, increases the quantum efficiency and hence improves the photocatalytic activity of the film effectively.展开更多
A NiP/TiO2 composite film on carbon steel was prepared by electroless plating and sol-gel composite process. An artificial neural network was applied to optimize the prepared condition of the composite film. Corrosion...A NiP/TiO2 composite film on carbon steel was prepared by electroless plating and sol-gel composite process. An artificial neural network was applied to optimize the prepared condition of the composite film. Corrosion behavior of the NiP/TiO2 composite film was investigated by polarization resistance measurement, anode polarization, ESEM （environmental scanning electron microscopy） and EIS （electrochemical impedance spectroscopy） measurements. Results showed that the NiP/ TiO2 composite film has a good corrosion resistance in 0.5mol/L H2SO4 solution. The element valence of the composite film was characterized by XPS （X-ray photoelectron spectroscopy） spectrum, and an anticorrosion mechanism of the composite film was discussed.展开更多
(PEO)8LiClO4-SiO2 composite polymer electrolytes(CPEs)were prepared by in-situ reaction,in which ethyl-orthosilicate(TEOS)was catalyzed by HCl and NH3.H2O,respectively.The ionic conductivity,the contact angle and the ...(PEO)8LiClO4-SiO2 composite polymer electrolytes(CPEs)were prepared by in-situ reaction,in which ethyl-orthosilicate(TEOS)was catalyzed by HCl and NH3.H2O,respectively.The ionic conductivity,the contact angle and the morphology of inorganic particles in the CPEs were investigated by AC impedance spectra,contact angle method and TEM.The conductivities of acid-catalyzed CPE and alkali-catalyzed CPE are 2.2×10-5and 1.1×10-5S/cm respectively at 30℃.The results imply that the catalyst plays an important role in the structure of in-situ preparation of SiO2,and influences the surface energy and conductivity of CPE films directly.Meanwhile,the ionic conductivity is related to the surface energy.展开更多
Fe2O3/SiO2 nano-composite films were prepared by sol-gel technique combining heat treatment in the range of 100-900 ℃. The particle size was observed by FE-SEM. Optical properties of the films were investigated by UV...Fe2O3/SiO2 nano-composite films were prepared by sol-gel technique combining heat treatment in the range of 100-900 ℃. The particle size was observed by FE-SEM. Optical properties of the films were investigated by UV-visible spectra. Structural and magnetic characteristics were investigated through FT-IR and VSM. The transparency of the Fe2O3/SiO2 nano-composite films decreased with the content of the Fe2O3. Water and organic solvent in the films were evaporated with heat treatment, so the transparency of the films was enhanced under high temperature. It is also found that the saturation magnetization （Ms） of the films increases with the temperature. As the content of the Fe2O3 increases, when the content of the Fe2O3 is around 30wt%, the Ms of the films has a maximum value.展开更多
Series of TiO 2-ZnO heterojunction composite films with different n（Zn）/n（Ti） ratios were prepared by UDP450 magnetron sputter ion plating equipment, and the mole ratio of Zn to Ti was controlled by adjusting the ...Series of TiO 2-ZnO heterojunction composite films with different n（Zn）/n（Ti） ratios were prepared by UDP450 magnetron sputter ion plating equipment, and the mole ratio of Zn to Ti was controlled by adjusting the current values of sputtering target. The effects of n（Zn）/n（Ti） on the microstructures of TiO2-ZnO films were investigated by SEM, AFM, Raman and XPS, and their photocatalytic decomposition of methyl orange solutions was evaluated. The results show that an increase in n（Zn）/n（Ti） typically results in a decrease in the grain size of composite films firstly and then an increase of grain size, while an increase in n（Zn）/n（Ti） leads to an increase in film roughness firstly and then a decrease in film roughness. Both grain size and roughness of TiO2-ZnO films reach the maximum and minimum at n（Zn）/n（Ti） of 1/9.3, respectively. The n（Zn）/n（Ti） shows little effect on the valences of Zn and Ti elements, which mainly exist in the form of TiO2 and ZnO phases. The n（Zn）/n（Ti） has influence on the amount of anatase/rutile TiO2 heterojunction in the film. With increase of the n（Zn）/n（Ti）, the absorption intensity of the composite film increases and the absorption region extends to 450 nm, which is redshifted as much as 150 nm in comparison with the pure TiO2 films. However, the photocatalytic abilities of heterogeneous composite films do not depend on the n（Zn）/n（Ti） but rather on the microstructures of the TiO2-ZnO composite films. Degradation rate of the film reaches the maximum and the photocatalytic decomposition of pollutants works best when n（Zn）/n（Ti）=1：9.3.展开更多
Co−TiO2 nanocomposite films were prepared via magnetron sputtering at various substrate temperatures.The films comprise Co particles dispersed in an amorphous TiO2 matrix and exhibit coexisting ferromagnetic and super...Co−TiO2 nanocomposite films were prepared via magnetron sputtering at various substrate temperatures.The films comprise Co particles dispersed in an amorphous TiO2 matrix and exhibit coexisting ferromagnetic and superparamagnetic properties.When the substrate temperature increases from room temperature to 400℃,Co particles gradually grow,and the degree of Co oxidation significantly decreases.Consequently,the saturation magnetization increases from 0.13 to 0.43 T at the same Co content by increasing the substrate temperature from room temperature to 400℃.At a high substrate temperature,conductive pathways form among some of the clustered Co particles.Thus,resistivity rapidly declines from 1600 to 76μΩ·m.The magnetoresistive characteristic of Co−TiO2 films is achieved even at resistivity of as low as 76μΩ·m.These results reveal that the obtained nanocomposite films have low Co oxidation,high magnetization and magnetoresistance at room temperature.展开更多
Bi_(2)WO_(6) nanoplate/TiO_(2) nanowire and Bi_(2)WO_(6) nanoflower/TiO_(2) nanowire composite films were successfully prepared using a hydrothermal method.The results show that the light absorption for Bi_(2)WO_(6)/T...Bi_(2)WO_(6) nanoplate/TiO_(2) nanowire and Bi_(2)WO_(6) nanoflower/TiO_(2) nanowire composite films were successfully prepared using a hydrothermal method.The results show that the light absorption for Bi_(2)WO_(6)/TiO_(2) composite films is extended to the visible region after Bi_(2)WO_(6) nanoplates and nanoflowers are assembled onto TiO_(2) nanowires.Furthermore,Bi_(2)WO_(6) nanoflower/TiO_(2) nano wire composite film exhibits a better absorption property compared to Bi_(2)WO_(6) nanoplate/TiO_(2) nanowire film,which is mainly ascribed to the narrower bandgap of Bi_(2)WO_(6) nanoflower compared to that of Bi_(2)WO_(6) nanoplate.The photocurrent density for Bi_(2)WO_(6) nanoflower/TiO_(2) nanowire and Bi_(2)WO_(6) nanoplate/TiO_(2) nanowire composite films can reach 95 and 62.5 μA cm-2,respectively,which are much higher than that obtained for a pure TiO_(2) nanowire film(25 μA cm-2).Meanwhile,under illumination,the pure TiO_(2) nanowire,Bi_(2)WO_(6) nanoplate/TiO_(2) nanowire and Bi_(2)WO_(6) nanoflower/TiO_(2) nanowire films can reduce the potential of the coupled 304 stainless steel in 3.5 wt.%NaCl solution by 299,719 and 739 mV,respectively.Thus,Bi_(2)WO_(6) nanoflower/TiO_(2) nanowire film is found to provide the best effective photocathodic protection for 304 stainless steel.This work not only provides an example of shape-dependent photocathodic protection based on Bi_(2)WO_(6) but also opens up new possibilities to design an ideal microstructure on the basis of semiconductor materials for future applications of photocathodic protection.展开更多
In this work, TiO2/Ti composite films were fabricated by 2-setp MCT and the following high temperature oxidation. Antibacterial activity of the composite films treated by ultrasonic cleaning to increase the performanc...In this work, TiO2/Ti composite films were fabricated by 2-setp MCT and the following high temperature oxidation. Antibacterial activity of the composite films treated by ultrasonic cleaning to increase the performance reliability was examined. The prepared TiO2/Ti composite films showed high photocatalytic activity in the degradation of methylene blue solution. It is obvious that? TiO2/Ti composite films have antibacterial activity under UV irradiation.展开更多
In this work, CaF_2:Ln^(3+)(Ln:Er,Er/Yb)/Nafion composite films were prepared using Nafion as modifications and matrices by dripping method. The composite films were characterized by Fourier transform infrared spectro...In this work, CaF_2:Ln^(3+)(Ln:Er,Er/Yb)/Nafion composite films were prepared using Nafion as modifications and matrices by dripping method. The composite films were characterized by Fourier transform infrared spectroscopy(FT-IR), X-ray diffraction(XRD) and scanning electron microscopy(SEM). Composite films are transparent and CaF_2:Ln^(3+)(Ln:Er,Er/Yb) nanoparticles are well dispersed in Nafion films.The thicknesses of CaF_2:Er^(3+)/Nafion and CaF_2:Er^(3+),Yb^(3+)/Nafion composite film are about 77 and 73 μm,respectively. The nanoparticles in composite film possess cubic phase. CaF_2:Er^(3+),Yb^(3+)/Nafion composite film has stronger characteristic emission of Er^(3+) around 1530 nm with full width at half-maximum(FWHM) of 73 nm and longer luminescence lifetimes of 22.04 μs(25.03%) and 100.77 μs(74.97%).展开更多
This paper reports that single-layer and graded Au-TiO2 granular composite films with Au atom content 15%- 66% were prepared by using reactive co-sputtering technique. The third-order optical nonlinearity of single-la...This paper reports that single-layer and graded Au-TiO2 granular composite films with Au atom content 15%- 66% were prepared by using reactive co-sputtering technique. The third-order optical nonlinearity of single-layer and graded composite films was investigated by using s- and p-polarized Z-scans in femtosecond time scale. The nonlinear absorption coefficient βeff of single-layer Au-TiO2 films is measured to be -2.3×10^3-0.76×10^3 cm/GW with Au atom content 15%-66%. The βeff value of the 10-layer Au-TiO2 graded film is enhanced to be -2.1×10^4cm/GW calculated from p-polarized Z-scans, which is about ten times the maximum βeff of single-layer films. Broadened response in the wavelength region 730-860 nm of the enhanced optical nonlinearity of graded Au-TiO2 composite films was also investigated.展开更多
Nano sized powders of TiO2 （titanium dioxide） and Nb2O5 （Niobium （V） oxide） were used to fabricate TiO2/Nb2O5 composites thin films by EPD （electrophoretic deposition） technique. The metal oxide powders, toget...Nano sized powders of TiO2 （titanium dioxide） and Nb2O5 （Niobium （V） oxide） were used to fabricate TiO2/Nb2O5 composites thin films by EPD （electrophoretic deposition） technique. The metal oxide powders, together with magnesium nitrate hexahydrate pellets, were suspended in propan-2-ol inside an EPD cell. The electrodes, placed 1.2 cm apart, were partially immersed in the suspension and a DC potential applied across them. Key EPD process parameters, which include applied DC electric field, deposition time and solid concentration in suspension, were optimized through visual inspection and from UV-Vis-NIR spectrophotometer spectra. The highest （55%） transmittance was obtained for films with deposition time of 90 s, powder concentration of 0.01 g/40 mL, and 35 V DC （direct current） voltage. XRD micrographs confirmed that TiO2 and Nb2O5 particles were presented in the composite film. SEM （scanning electron microscope） micrographs of the composite electrode thin films showed that porous films of high quality with well controlled morphology were deposited by using the EPD technique.展开更多
The TiO2-Co-TiO2 sandwich films were successfully grown on glass and silicon substrata making alternate use of radio frequency reactive magnetron sputtering and direct current magnetron sputtering. The structures and ...The TiO2-Co-TiO2 sandwich films were successfully grown on glass and silicon substrata making alternate use of radio frequency reactive magnetron sputtering and direct current magnetron sputtering. The structures and properties of these films were identified with X-ray diffraction （XRD）, Raman spectra and X-ray photoemission spectra （XPS）. It is shown that the sandwich film consists of two anatase TiO2 films with an embedded Co nano-film. The fact that, when the Co nano-film thickens, varied red shifts appear in optical absorption spectra may well be explained by the quantum confinement and tunnel effects. As for magnetic properties, the saturation magnetization, remnant magnetic induction and coercivity vary with the thickness of the Co nano-films. Moreover, the Co nano-film has a critical thickness of about 8.6 mn, which makes the coercivity of the composite film reach the maximum of about 1413 Oe.展开更多
Titanium dioxide （TiO2） loaded tungsten trioxide （WO3） composite films are prepared by an E-beam vapor system. Associated with the existence of a heterojunction at the interface of TiO2 and WO3, the prepared TiO2-...Titanium dioxide （TiO2） loaded tungsten trioxide （WO3） composite films are prepared by an E-beam vapor system. Associated with the existence of a heterojunction at the interface of TiO2 and WO3, the prepared TiO2-WO3 composite film shows enhanced photocurrent density, four times than the pure WO3 film illuminated under xenon lamp, and higher incident-photon-to-current conversion e^ciency. By varying the initial TiO2 film thickness, such composite structures could be optimized to obtain the highest photocurrent density. We believe that thin TiO2 films improve the light response and increase the surface roughness of WO3 films. Furthermore, the existence of the heterojunction results in the e^cient charge carriers＇ separation, transfer process, and a lower recombination of electron-hole pairs, which is beneficial for the enhancement of photocurrent density.展开更多
In this work,flexible photothermal PVA/Ti_(2)O_(3) composite films with different amount(0 wt%,5 wt%,10 wt%,15 wt%)of Ti_(2)O_(3) particles modified by steric acid were prepared by a simple solution casting method.The...In this work,flexible photothermal PVA/Ti_(2)O_(3) composite films with different amount(0 wt%,5 wt%,10 wt%,15 wt%)of Ti_(2)O_(3) particles modified by steric acid were prepared by a simple solution casting method.The microstructures,XRD patterns,FTIR spectra,UV-Vis-NIR spectra thermo-conductivity,thermo-stability and photothermal effects of these composite films were all characterized.These results indicated that Ti_(2)O_(3) particles were well dispersed throughout the polyvinyl alcohol(PVA)matrix in the PVA/Ti_(2)O_(3) composite films.And Ti_(2)O_(3) particles could also effectively improve the photothermal properties of the composite films which exhibited high light absorption and generated a high temperature(about 57.4℃for film with 15 wt%Ti_(2)O_(3) amount)on the surface when it was irradiated by a simulated sunlight source(1 kW/m^(2)).展开更多
Tetravalent tin(Sn^(4+))-based inorganic perovskite semiconductors like Cs_(2)SnI_(6)are expected to replace lead-based perovskite counterparts due to advantages such as structural stability and environmental friendli...Tetravalent tin(Sn^(4+))-based inorganic perovskite semiconductors like Cs_(2)SnI_(6)are expected to replace lead-based perovskite counterparts due to advantages such as structural stability and environmental friendliness.In this paper,we reported the dopant compensation effect in the component-dependent self-doped(111)-oriented Cs_(2)SnI_(6)thin films grown with pulsed laser deposition(PLD)at room temperature.The films were grown on(100)-SrTiO_(3)(STO)substrates at room temperature by PLD.Hall results of the Cs_(2)SnI_(6)films with different components realizing by controlling the ratio of SnI_(4)/CsI in the targets demonstrate a clear change of conductivity type from N-type to P-type,while the carrier concentration decreases from 1018 to 1013 and accordingly the film resistivity increases significantly from 3.8 to 2506Ωcm.The defect-relatedopticalfingerprints of Cs_(2)SnI_(6)films werealsoinvestigated withtemperature-dependent photoluminescence spectroscopy.At low temperatures of 10 K,the Cs_(2)SnI_(6)films exhibit donor-bound(D^(0)X)and donor-acceptor pair(DAP)emission,respectively,due to the self-doping effect.These re-sults indicate that controlling the composition of the PLD target is a powerful way to tune the electrical properties of Cs_(2)SnI_(6)films for possible applications in solar cells or X-ray detectors.展开更多
文摘Total dose effects and single event effects on radiation-hardened power vertical double-diffusion metal oxide semiconductor（VDMOS） devices with composite SiO2-Si3N4 film gates are investigated.The relationships among the important electrical parameters of the samples with different thickness SiO2-Si3N4 films,such as threshold voltage,breakdown voltage,and on-state resistance in accumulated dose,are discussed.The total dose experiment results show that the breakdown voltage and the on-state resistance barely change with the accumulated dose.However,the relationships between the threshold voltages of the samples and the accumulated dose are more complex,and not only positively drift,but also negatively drift.At the end of the total dose experiment,we select the group of samples which have the smaller threshold voltage shift to carry out the single event effect studies.We find that the samples with appropriate thickness ratio SiO2-Si3N4 films have a good radiation-hardening ability.This method may be useful in solving both the SEGR and the total dose problems with the composite SiO2-Si3N4 films.
基金financially supported by the National Natural Science Foundation of China (Nos. 51073004 and 21074141)the China National Funds for Distinguished Young Scientists (No. 50925313)
文摘In the present work, structure changes during （SiO2） composites have been investigated systematically stretching of isotactic polypropylene （iPP） and iPP/silicon dioxide The or-form crystal structure of both iPP and iPP/SiO2 composites is destroyed and transforms into the mesophase as the samples are stretched at a low temperature （35℃）, while stretching at high temperatures （90℃ and 120℃） can restrain the appearance of defects and keep the perfection of crystal structure. FTIR results reveal that the stretching temperatures show no obvious difference of the effect on the orientation of pure iPP, however, the orientation of iPP/SiO2 composites is greatly changed by the tensile temperature. In the case of micron-sized SiO2 particles （average particle diameter d 〉 1 μm）, the orientation of the composites is lower than that of pure iPP at all stretching temperatures. The above results suggest that the stretching temperature and the SiO2 particle size have great influence on the structure variation and orientation behavior of iPP/SiO2 composites.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 50842028 and 50972012)the National Basic Research Program of China (Grant No 2007CB613301)
文摘Nano metal-particle dispersed glasses are the attractive candidates for nonlinear optical material applications. Au/SiO2 nano-composite thin films with 3 vol% to 65 vol% Au are prepared by inductively coupled plasma sputtering. Au particles as perfect spheres with diameters between 10 nm and 30 nm are uniformly dispersed in the SiO2 matrix. Optical absorption peaks due to the surface plasmon resonance of Au particles are observed. The absorption property is enhanced with the increase of Au content, showing a maximum value in the films with 37 vol% Au. The absorption curves of the Au/SiO2 thin films with 3 vol% to 37 vol% Au accord well with the theoretical optical absorption spectra obtained from Mie resonance theory. Increasing Au content over 37 vol% results in the partial connection of Au particles, whereby the intensity of the absorption peak is weakened and ultimately replaced by the optical absorption of the bulk. The band gap decreases with Au content increasing from 3 vol% to 37 vol % but increases as Au content further increases.
基金Sponsored by Hi-Tech Research and Development Program of China (2003AA305120)
文摘The Ni-P/TiO2 composite film on sintered NdFeB permanent magnet was investigated by X-ray diffraction （XRD）,environmental scanning electron microscopy （ESEM）,and energy dispersive X-ray spectrometer （EDX）. The corrosion resistance of Ni-P/TiO2 film coated on NdFeB magnet,in 0.5 mol/L NaCl solution,was studied by potentiodynamic polarization,salt spray test and electrochemical impedance spectroscopy （EIS） techniques. The self-corrosion current density （icorr） and the polarization resistance （Rp） of Ni-P/TiO2 film are 0.22 μA/cm2 （about 14% of that of Ni-P coating）,and 120 kΩ·cm2 （about 2 times of that of Ni-P coating）,respectively. The anti-salt spray time of Ni-P/TiO2 film is about 2.5 times of that of the Ni-P coating. The results indicate that Ni-P/TiO2 film has a better corrosion resistance than Ni-P coating,and the composite film increases the corrosion resistance of NdFeB magnet markedly.
基金Project(gf200901002)supported by the Open Research Fund of National Defense Key Disciplines Laboratory of Light Alloy Processing Science and Technology of Nanchang Hangkong University,China
文摘ZrO2/TiO2 composite photocatalytic film was produced on the pure titanium substrate using in-situ Zr（OH）4 colloidal particle by the micro-arc oxidation technique and characterized by scanning electron microscope （SEM）, energy dispersive X-ray （EDX）, X-ray diffraction （XRD） and ultraviolet-visible （UV-Vis） spectrophotometer. The composite film shows a lamellar and porous structure which consists of anatase, futile and ZrO2 phases. The optical absorption edge of film is shifted to longer wavelength when ZrO2 is introduced to TiO2. Furthermore, the photocatalytic reaction rate constants of degradation of rhodamine B solution with ZrO2/TiO2 composite film and pure TiO2 film under ultraviolet irradiation are measured as 0.0442 and 0.0186 h 1, respectively.
基金financially supported by the National Natural Science Foundation of China (No.51301118)the Projects of International Cooperation in Shanxi (No.2014081002)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi (No.2013108)
文摘Cu2O/TiOa/Pt three-layer films were deposited on glass substrates using magnetron sputtering method. The surface morphology and the optical properties of the composite film were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, ultraviolet- visible spectroscopy （UV-Vis） and photoluminescence spectroscopy （PL）. The photocatalytic activity of the samples was evaluated by the photocatalytic degradation of methyl orange （MO） aqueous solution under visible light irradiation. The results indicate that the Cu2O/TiO2/Pt composite films are made up of three layers which are Pt layer, anatase-TiO2 layer and Cu2O layer from bottom to top. The surface of the films is even and composed of regular-shaped spherical particles. The photocatalytic activity of the Cu2O/TiO2/Pt three-layer film is much higher than that of the Cu2O/TiO2 double-layer film. Such enhancement is ascribed to the presence of Pt layer, which further inhibits the photogenerated electron-hole recombination, prolongs the lifetime of the photogenerated carriers, increases the quantum efficiency and hence improves the photocatalytic activity of the film effectively.
文摘A NiP/TiO2 composite film on carbon steel was prepared by electroless plating and sol-gel composite process. An artificial neural network was applied to optimize the prepared condition of the composite film. Corrosion behavior of the NiP/TiO2 composite film was investigated by polarization resistance measurement, anode polarization, ESEM （environmental scanning electron microscopy） and EIS （electrochemical impedance spectroscopy） measurements. Results showed that the NiP/ TiO2 composite film has a good corrosion resistance in 0.5mol/L H2SO4 solution. The element valence of the composite film was characterized by XPS （X-ray photoelectron spectroscopy） spectrum, and an anticorrosion mechanism of the composite film was discussed.
文摘(PEO)8LiClO4-SiO2 composite polymer electrolytes(CPEs)were prepared by in-situ reaction,in which ethyl-orthosilicate(TEOS)was catalyzed by HCl and NH3.H2O,respectively.The ionic conductivity,the contact angle and the morphology of inorganic particles in the CPEs were investigated by AC impedance spectra,contact angle method and TEM.The conductivities of acid-catalyzed CPE and alkali-catalyzed CPE are 2.2×10-5and 1.1×10-5S/cm respectively at 30℃.The results imply that the catalyst plays an important role in the structure of in-situ preparation of SiO2,and influences the surface energy and conductivity of CPE films directly.Meanwhile,the ionic conductivity is related to the surface energy.
基金Funded by the Innovative Program of Shanghai Municipal Education Commission (No.08YZ97)the National Natural Science Foundation of China (No.10704048)
文摘Fe2O3/SiO2 nano-composite films were prepared by sol-gel technique combining heat treatment in the range of 100-900 ℃. The particle size was observed by FE-SEM. Optical properties of the films were investigated by UV-visible spectra. Structural and magnetic characteristics were investigated through FT-IR and VSM. The transparency of the Fe2O3/SiO2 nano-composite films decreased with the content of the Fe2O3. Water and organic solvent in the films were evaporated with heat treatment, so the transparency of the films was enhanced under high temperature. It is also found that the saturation magnetization （Ms） of the films increases with the temperature. As the content of the Fe2O3 increases, when the content of the Fe2O3 is around 30wt%, the Ms of the films has a maximum value.
基金Project (2010JQ6008) supported by the Natural Science Foundation of Shaanxi Province,China
文摘Series of TiO 2-ZnO heterojunction composite films with different n（Zn）/n（Ti） ratios were prepared by UDP450 magnetron sputter ion plating equipment, and the mole ratio of Zn to Ti was controlled by adjusting the current values of sputtering target. The effects of n（Zn）/n（Ti） on the microstructures of TiO2-ZnO films were investigated by SEM, AFM, Raman and XPS, and their photocatalytic decomposition of methyl orange solutions was evaluated. The results show that an increase in n（Zn）/n（Ti） typically results in a decrease in the grain size of composite films firstly and then an increase of grain size, while an increase in n（Zn）/n（Ti） leads to an increase in film roughness firstly and then a decrease in film roughness. Both grain size and roughness of TiO2-ZnO films reach the maximum and minimum at n（Zn）/n（Ti） of 1/9.3, respectively. The n（Zn）/n（Ti） shows little effect on the valences of Zn and Ti elements, which mainly exist in the form of TiO2 and ZnO phases. The n（Zn）/n（Ti） has influence on the amount of anatase/rutile TiO2 heterojunction in the film. With increase of the n（Zn）/n（Ti）, the absorption intensity of the composite film increases and the absorption region extends to 450 nm, which is redshifted as much as 150 nm in comparison with the pure TiO2 films. However, the photocatalytic abilities of heterogeneous composite films do not depend on the n（Zn）/n（Ti） but rather on the microstructures of the TiO2-ZnO composite films. Degradation rate of the film reaches the maximum and the photocatalytic decomposition of pollutants works best when n（Zn）/n（Ti）=1：9.3.
基金Project(2016YFE0205700)supported by the National Key Research and Development Program of ChinaProject(18JCYBJC18000)supported by the Natural Science Foundation of Tianjin City,China。
文摘Co−TiO2 nanocomposite films were prepared via magnetron sputtering at various substrate temperatures.The films comprise Co particles dispersed in an amorphous TiO2 matrix and exhibit coexisting ferromagnetic and superparamagnetic properties.When the substrate temperature increases from room temperature to 400℃,Co particles gradually grow,and the degree of Co oxidation significantly decreases.Consequently,the saturation magnetization increases from 0.13 to 0.43 T at the same Co content by increasing the substrate temperature from room temperature to 400℃.At a high substrate temperature,conductive pathways form among some of the clustered Co particles.Thus,resistivity rapidly declines from 1600 to 76μΩ·m.The magnetoresistive characteristic of Co−TiO2 films is achieved even at resistivity of as low as 76μΩ·m.These results reveal that the obtained nanocomposite films have low Co oxidation,high magnetization and magnetoresistance at room temperature.
基金supported by the National Natural Science Foundation of China(Nos.51822402,51671044 and 52001051)the National Key Research and Development Program of China(Nos.2019YFA0209901 and 2018YFA0702901)+4 种基金the fund of the State Key Laboratory of Solidification Processing in NWPU(Grant No.SKLSP201902)the Liao Ning Revitalization Talents Program(XLYC1807047)the National MCF Energy R&D Program(No.2018YFE0312400)the Fund of Science and Technology on Reactor Fuel and Materials Laboratory(STRFML-2020-04)the China Postdoctoral Science Foundation(No.2020M670747).
文摘Bi_(2)WO_(6) nanoplate/TiO_(2) nanowire and Bi_(2)WO_(6) nanoflower/TiO_(2) nanowire composite films were successfully prepared using a hydrothermal method.The results show that the light absorption for Bi_(2)WO_(6)/TiO_(2) composite films is extended to the visible region after Bi_(2)WO_(6) nanoplates and nanoflowers are assembled onto TiO_(2) nanowires.Furthermore,Bi_(2)WO_(6) nanoflower/TiO_(2) nano wire composite film exhibits a better absorption property compared to Bi_(2)WO_(6) nanoplate/TiO_(2) nanowire film,which is mainly ascribed to the narrower bandgap of Bi_(2)WO_(6) nanoflower compared to that of Bi_(2)WO_(6) nanoplate.The photocurrent density for Bi_(2)WO_(6) nanoflower/TiO_(2) nanowire and Bi_(2)WO_(6) nanoplate/TiO_(2) nanowire composite films can reach 95 and 62.5 μA cm-2,respectively,which are much higher than that obtained for a pure TiO_(2) nanowire film(25 μA cm-2).Meanwhile,under illumination,the pure TiO_(2) nanowire,Bi_(2)WO_(6) nanoplate/TiO_(2) nanowire and Bi_(2)WO_(6) nanoflower/TiO_(2) nanowire films can reduce the potential of the coupled 304 stainless steel in 3.5 wt.%NaCl solution by 299,719 and 739 mV,respectively.Thus,Bi_(2)WO_(6) nanoflower/TiO_(2) nanowire film is found to provide the best effective photocathodic protection for 304 stainless steel.This work not only provides an example of shape-dependent photocathodic protection based on Bi_(2)WO_(6) but also opens up new possibilities to design an ideal microstructure on the basis of semiconductor materials for future applications of photocathodic protection.
文摘In this work, TiO2/Ti composite films were fabricated by 2-setp MCT and the following high temperature oxidation. Antibacterial activity of the composite films treated by ultrasonic cleaning to increase the performance reliability was examined. The prepared TiO2/Ti composite films showed high photocatalytic activity in the degradation of methylene blue solution. It is obvious that? TiO2/Ti composite films have antibacterial activity under UV irradiation.
基金Project supported by Natural Science Basic Research Plan in Shaanxi Province of China(No.2018JM2021)Xi'an Science and Technology Plan Project(2016CXWL10,CXY1443WL21)Program of Education Department of Shaanxi Provincial Government(15JK2152)
文摘In this work, CaF_2:Ln^(3+)(Ln:Er,Er/Yb)/Nafion composite films were prepared using Nafion as modifications and matrices by dripping method. The composite films were characterized by Fourier transform infrared spectroscopy(FT-IR), X-ray diffraction(XRD) and scanning electron microscopy(SEM). Composite films are transparent and CaF_2:Ln^(3+)(Ln:Er,Er/Yb) nanoparticles are well dispersed in Nafion films.The thicknesses of CaF_2:Er^(3+)/Nafion and CaF_2:Er^(3+),Yb^(3+)/Nafion composite film are about 77 and 73 μm,respectively. The nanoparticles in composite film possess cubic phase. CaF_2:Er^(3+),Yb^(3+)/Nafion composite film has stronger characteristic emission of Er^(3+) around 1530 nm with full width at half-maximum(FWHM) of 73 nm and longer luminescence lifetimes of 22.04 μs(25.03%) and 100.77 μs(74.97%).
基金Project supported by the National Natural Science Foundation of China (Grant No 10474075)
文摘This paper reports that single-layer and graded Au-TiO2 granular composite films with Au atom content 15%- 66% were prepared by using reactive co-sputtering technique. The third-order optical nonlinearity of single-layer and graded composite films was investigated by using s- and p-polarized Z-scans in femtosecond time scale. The nonlinear absorption coefficient βeff of single-layer Au-TiO2 films is measured to be -2.3×10^3-0.76×10^3 cm/GW with Au atom content 15%-66%. The βeff value of the 10-layer Au-TiO2 graded film is enhanced to be -2.1×10^4cm/GW calculated from p-polarized Z-scans, which is about ten times the maximum βeff of single-layer films. Broadened response in the wavelength region 730-860 nm of the enhanced optical nonlinearity of graded Au-TiO2 composite films was also investigated.
文摘Nano sized powders of TiO2 （titanium dioxide） and Nb2O5 （Niobium （V） oxide） were used to fabricate TiO2/Nb2O5 composites thin films by EPD （electrophoretic deposition） technique. The metal oxide powders, together with magnesium nitrate hexahydrate pellets, were suspended in propan-2-ol inside an EPD cell. The electrodes, placed 1.2 cm apart, were partially immersed in the suspension and a DC potential applied across them. Key EPD process parameters, which include applied DC electric field, deposition time and solid concentration in suspension, were optimized through visual inspection and from UV-Vis-NIR spectrophotometer spectra. The highest （55%） transmittance was obtained for films with deposition time of 90 s, powder concentration of 0.01 g/40 mL, and 35 V DC （direct current） voltage. XRD micrographs confirmed that TiO2 and Nb2O5 particles were presented in the composite film. SEM （scanning electron microscope） micrographs of the composite electrode thin films showed that porous films of high quality with well controlled morphology were deposited by using the EPD technique.
基金Aeronautical Science Foundation of China (03G51069)Items of Engineering Research Institute, Peking University (ERIPKU-204031)
文摘The TiO2-Co-TiO2 sandwich films were successfully grown on glass and silicon substrata making alternate use of radio frequency reactive magnetron sputtering and direct current magnetron sputtering. The structures and properties of these films were identified with X-ray diffraction （XRD）, Raman spectra and X-ray photoemission spectra （XPS）. It is shown that the sandwich film consists of two anatase TiO2 films with an embedded Co nano-film. The fact that, when the Co nano-film thickens, varied red shifts appear in optical absorption spectra may well be explained by the quantum confinement and tunnel effects. As for magnetic properties, the saturation magnetization, remnant magnetic induction and coercivity vary with the thickness of the Co nano-films. Moreover, the Co nano-film has a critical thickness of about 8.6 mn, which makes the coercivity of the composite film reach the maximum of about 1413 Oe.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11174137,11474215 and 21204058the Natural Science Foundation for the Youth of Jiangsu Province under Grant No BK20130284the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Titanium dioxide （TiO2） loaded tungsten trioxide （WO3） composite films are prepared by an E-beam vapor system. Associated with the existence of a heterojunction at the interface of TiO2 and WO3, the prepared TiO2-WO3 composite film shows enhanced photocurrent density, four times than the pure WO3 film illuminated under xenon lamp, and higher incident-photon-to-current conversion e^ciency. By varying the initial TiO2 film thickness, such composite structures could be optimized to obtain the highest photocurrent density. We believe that thin TiO2 films improve the light response and increase the surface roughness of WO3 films. Furthermore, the existence of the heterojunction results in the e^cient charge carriers＇ separation, transfer process, and a lower recombination of electron-hole pairs, which is beneficial for the enhancement of photocurrent density.
基金Funded by the Youth Backbone Teacher Training Plan in University of Henan Province(No.21220028)Science and Technology Research Project of Henan Province(No.242102321066)+2 种基金Natural Science Foundation of Henan Province(No.232300420312)Henan University of Technology Young Backbone Teacher Training Plan(No.21421260)the Innovation Training Program for College Students in Henan Province(No.202310463046)。
文摘In this work,flexible photothermal PVA/Ti_(2)O_(3) composite films with different amount(0 wt%,5 wt%,10 wt%,15 wt%)of Ti_(2)O_(3) particles modified by steric acid were prepared by a simple solution casting method.The microstructures,XRD patterns,FTIR spectra,UV-Vis-NIR spectra thermo-conductivity,thermo-stability and photothermal effects of these composite films were all characterized.These results indicated that Ti_(2)O_(3) particles were well dispersed throughout the polyvinyl alcohol(PVA)matrix in the PVA/Ti_(2)O_(3) composite films.And Ti_(2)O_(3) particles could also effectively improve the photothermal properties of the composite films which exhibited high light absorption and generated a high temperature(about 57.4℃for film with 15 wt%Ti_(2)O_(3) amount)on the surface when it was irradiated by a simulated sunlight source(1 kW/m^(2)).
基金financially supported by the National Key Re-search and Development Program of China(No.2022YFC3700801)the Key R&D Program of Shandong Province,China(No.2024SFGC0102),the Jinan Bureau of Education(No.JNSX2023015)the Jinan Bureau of Science and Technology(No.202333042).
文摘Tetravalent tin(Sn^(4+))-based inorganic perovskite semiconductors like Cs_(2)SnI_(6)are expected to replace lead-based perovskite counterparts due to advantages such as structural stability and environmental friendliness.In this paper,we reported the dopant compensation effect in the component-dependent self-doped(111)-oriented Cs_(2)SnI_(6)thin films grown with pulsed laser deposition(PLD)at room temperature.The films were grown on(100)-SrTiO_(3)(STO)substrates at room temperature by PLD.Hall results of the Cs_(2)SnI_(6)films with different components realizing by controlling the ratio of SnI_(4)/CsI in the targets demonstrate a clear change of conductivity type from N-type to P-type,while the carrier concentration decreases from 1018 to 1013 and accordingly the film resistivity increases significantly from 3.8 to 2506Ωcm.The defect-relatedopticalfingerprints of Cs_(2)SnI_(6)films werealsoinvestigated withtemperature-dependent photoluminescence spectroscopy.At low temperatures of 10 K,the Cs_(2)SnI_(6)films exhibit donor-bound(D^(0)X)and donor-acceptor pair(DAP)emission,respectively,due to the self-doping effect.These re-sults indicate that controlling the composition of the PLD target is a powerful way to tune the electrical properties of Cs_(2)SnI_(6)films for possible applications in solar cells or X-ray detectors.
