The cyclic voltammetry and potential step methods were used to investigate the electrochemical behavior of Fe 2+ and La 3+ in FeCl 2 LiCl DMSO and LaCl 3 LiCl DMSO systems on Pt, Cu and Ni cathodes. Th...The cyclic voltammetry and potential step methods were used to investigate the electrochemical behavior of Fe 2+ and La 3+ in FeCl 2 LiCl DMSO and LaCl 3 LiCl DMSO systems on Pt, Cu and Ni cathodes. The electroreduction of Fe 2+ to Fe is irreversible in one step,while the electroreduction of La 3+ to La is quasi reversible. The diffusion coefficient of La 3+ in LaCl 3 LiCl DMSO system at 298 K was 3 1×10 -6 cm 2·s -1 . The diffusion coefficient and transfer coefficient of Fe 2+ in FeCl 2 LiCl DMSO system at 298 K were 2 54×10 -6 cm 2·s -1 and 0 24, respectively. La Fe alloy films containing La from 22 7% to 37 1% (mass fraction) were prepared by potentiostatic electrolysis on Cu substrates at a deposition potential from -1 750 to -2 450 V (vs SCE). The fine La Fe alloy films were also obtained by pulse electrolysis at a pulse current densities from 2 to 6 mA·cm -2 . The surfaces of these alloy films are smooth, adhesive and uniform, and have metallic luster.展开更多
The physical vapour deposition of Ni atoms on α-Fe（001） surface under different deposition temperatures were simulated by molecular dynamics to study the intermixing and microstructure of the interracial region. Th...The physical vapour deposition of Ni atoms on α-Fe（001） surface under different deposition temperatures were simulated by molecular dynamics to study the intermixing and microstructure of the interracial region. The results indicate that Ni atoms hardly penetrate into Fe substrate while Fe atoms easily diffuse into Ni deposition layers. The thickness of the intermixing region is temperature-dependent, with high temperatures yielding larger thicknesses. The deposited layers are mainly composed of amorphous phase due to the abnormal deposition behaviour of Ni and Fe. In the deposited Ni-rich phase, the relatively stable metallic compound B2 structured FeNi is found under high deposition temperature conditions.展开更多
The Fe_3O_4/Fe/Fe_3O_4 (MIM) tri-layer films (200 nm/12-93 nm/200 um) were prepared on Si(100) by DC-magnetron reactive-sputtering followed by air- or vacuum-annealing at 280-400℃ for 1.5 h, respectively. Magnetic pr...The Fe_3O_4/Fe/Fe_3O_4 (MIM) tri-layer films (200 nm/12-93 nm/200 um) were prepared on Si(100) by DC-magnetron reactive-sputtering followed by air- or vacuum-annealing at 280-400℃ for 1.5 h, respectively. Magnetic properties and phases under different sandwich and annealing conditions were studied. In MIM structure, the incorporation of the interlayer iron does increase the magnetization measured under 8 kOe (M_8K), but reduce coercivity (H_c). The H_c of asdeposited films decreases from 354 Oe to 74 Oe; while M_8K increases from 254 to 392 emu/cc. By annealing in air, the whole MIM tri-layer film becomes γ-F_e2O_3, H_c is about 550 O_e and M_8K is around 250 emu/cc. The coercivity mechanism of as-deposited and annealed MIM trilayer films belongs to domain-wall pinning type. δM plots show that when the interlayer Fe thickness is 12 um, the Fe and Fe_3O_4 layers are decoupled in the as-deposited and annealed states; while it is coupled in the as deposited state when the Fe thickness increases to 23 um. Vacuum annealing of the MIM films leads to increase in both coercivity and magnetization, and to enhance the exchange coupling between layers.展开更多
Permeability characteristics of sputtered soft magnetic Fe40Co40B20 thin films are investigated in the range of O. 5 to 5 GHz by a shortened microstrip transmission line perturbation method. Excellent microwave permea...Permeability characteristics of sputtered soft magnetic Fe40Co40B20 thin films are investigated in the range of O. 5 to 5 GHz by a shortened microstrip transmission line perturbation method. Excellent microwave permeability is achieved at 0.4 Pa argon pressure： fr is 3.32 GHz, the real and imaginary part of permeability at 0.5 GHz are 104 and 61, respectively. In addition, the thickness effect on permeability is also studied. The minimum damping can be achieved at the thinnest film. Different sources contributed to in-plane anisotropy are discussed briefly. The deviation between the peak frequency of the imaginary part and the zero-crossing frequency of the real part of permeability is also presented.展开更多
Precursive iron films with different grain sizes were prepared by magnetron sputtering on substrates heated at different temperatures. The iron films were sulfurized at 673 K for 20 h to form pyrite films. The structu...Precursive iron films with different grain sizes were prepared by magnetron sputtering on substrates heated at different temperatures. The iron films were sulfurized at 673 K for 20 h to form pyrite films. The structural and electrical characters were determined. High substrate temperatures produce large crystallites in the precursive iron films. The pyrite films are composed of a surface layer with coarse columnar grains and a bottom layer with fine equiaxed grains. With the increase of iron grain scale, the carrier concentration decreases and the carrier mobility increases. The electrical resistivity of the pyrite films increases to a maximum in the precursive iron films with increasing the grain size to about 3g nm. Sufficient formation and growth of iron grains result in improved crystallinity and high continuity of the pyrite films. The crystal defect density, transformation stress level and atom diffusion behavior are responsible for the characteristics of the electrical properties dependent on the crystallinity and continuity of the pyrite films or the crystallizing status of the precursive iron films.展开更多
Ni80Fe20/Ni48Fe12Cr40 bilayer films and Ni80Fe20 monolayer films were deposited at room temperature on SiO2/Si（100） substrates by electron beam evaporation. The influence of the thickness of the Ni48Fe12Cr40 underla...Ni80Fe20/Ni48Fe12Cr40 bilayer films and Ni80Fe20 monolayer films were deposited at room temperature on SiO2/Si（100） substrates by electron beam evaporation. The influence of the thickness of the Ni48Fe12Cr40 underlayer on the structure, magnetization, and magnetoresistance of the Ni80Fe20/Ni48Fe12Cr40 bilayer film was investigated. The thickness of the Ni48Fe12Cr40 layer varied from about 1 nm to 18 nm while the Ni80Fe20 layer thickness was fixed at 45 nm. For the as-deposited bilayer films the introducing of the Ni48Fe12Cr40 underlayer promotes both the （111） texture and grain growth in the Ni80Fe20 layer. The Ni48Fe12Cr40 underlayer has no significant influence on the magnetic moment of the Ni80Fe20/Ni48Fe12Cr40 bilayer film. However, the coercivity of the bilayer film changes with the thickness of the Ni48Fe12Cr40 undedayer. The optimum thickness of the Ni48Fe12Cr40 underlayer for improving the anisotropic magnetoresistance effect of the Ni80Fe20/Ni48Fe12Cr40 bilayer film is about 5 nm. With a decrease in temperature from 300 K to 81 K, the anisotropic magnetoresistance ratio of the Ni80Fe20 （45 nm）/Ni48Fe12Cr40 （5 nm） bilayer film increases linearly from 2.1% to 4.8% compared with that of the Ni80Fe20 monolayer film from 1.7% to 4.0%.展开更多
In the present work,ferrite(Fe)doped TiO_(2)thin films with different volume percentage(vol%)were synthesized using a spray pyrolysis technique.The effect of Fe doping on structural properties such as crystallite size...In the present work,ferrite(Fe)doped TiO_(2)thin films with different volume percentage(vol%)were synthesized using a spray pyrolysis technique.The effect of Fe doping on structural properties such as crystallite size,texture coefficient,microstrain,dislocation densities etc.were evaluated from the X ray diffratometry(XRD)data.XRD data revealed a polycrystalline anatase TiO_(2)phase for sample synthesized up to 2 vol%and mixed anatase and rutile crystalline phase for sample synthesized at 4 vol%Fe doped TiO_(2).The crystalline size was observed to decrease with increase in Fe dopant vol%and also other structural parameters changes with Fe dopant percentage.In the present work,electrical resistance was observed to decrease with a rise in Fe dopant vol%and temperature of the sample.Thermal properties like temperature coefficient of resistance and activation energy also showed strong correlation with Fe dopant vol%.Humidity sensing properties of the synthesized sample altered with a change in Fe dopant vol%.In the present paper,maximum sensitivity of about 88.7%for the sample synthesized with 2 vol%Fe doped TiO_(2)and also the lowest response and recovery time of about 52 and 3 s were reported for the same sample.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
A Fe-Ni soft magnetic film was prepared in sulphate solution by electroplating. The influences of the molar ratio of n[Fe2+]/n[Ni2+], current density, bath temperature, pH and L-ascorbic acid concentration on magnetic...A Fe-Ni soft magnetic film was prepared in sulphate solution by electroplating. The influences of the molar ratio of n[Fe2+]/n[Ni2+], current density, bath temperature, pH and L-ascorbic acid concentration on magnetic properties of Fe-Ni alloy film were investigated. The results show that the saturated flux density(BS) of the film increases initially and decreases after it reaches the specific value with the increase of n[Fe2+]/n[Ni2+] molar ratio, current density, bath temperature and pH. However, the relationship between L-ascorbic acid concentration and BS keeps linear. It is observed that the coercive force(Hc) is enhanced with the increase of n[Fe2+]/n[Ni2+] molar ratio, current density and pH. By comparison, when the bath temperature increases, Hc always decreases. With the increase of L-ascorbic acid concentration, the coercive force increases initially and then decreases.展开更多
The nanotitanium dioxide （TiO2） photocatalytic and porous ceramic filtering technique is one of the advanced methods to effectively treat organic wastewater. The TiO2 sol doped with Fe^3＋ ions was prepared by sol-g...The nanotitanium dioxide （TiO2） photocatalytic and porous ceramic filtering technique is one of the advanced methods to effectively treat organic wastewater. The TiO2 sol doped with Fe^3＋ ions was prepared by sol-gel processing. The influences of the process conditions of coating nanophotocatalytic material- Fe^3＋-TiO2 film on the surface of porous ceramic filter by dipping-lift method on the performance of porous ceramic filter were studied. The porous ceramic filters have two functions at the same time, filtration and photocatalytic degradation. The results of this study showed that the pH and viscosity of the sol, amount of Fe^3＋ ions doped as well as the coating times greatly affect the quality of coating film, the performance parameters and the photocatalytic activity of the porous ceramic filter. When the pH of the sol is 3-4, the viscosity is about 6 mPa.S, the amount of doped Fe^3＋ ions is about 2.0 g/L, the porous ceramic filter has been shown to have the best filtering performance and photocatalytic activity. In this condition, the porosity of porous ceramic is about 42.5%, the pore diameter is 8-10μm. The degradation of methyl-orange is 74.76% under lighting for 120 rain.展开更多
200 nm thick Fe-N magnetic thin films were deposited on glass substrates by RF sputtering. The as-deposited films have high saturation magnetization but their coercivity is also higher than what is needed Therefore it...200 nm thick Fe-N magnetic thin films were deposited on glass substrates by RF sputtering. The as-deposited films have high saturation magnetization but their coercivity is also higher than what is needed Therefore it is very important to reduce coercivity. The samples were vacuum annealed at 250℃ under 12000 A/m magnetic field. When the N content was in the range of 5-7 at. pct, the thin films consisted of α' +α' after heat treatment and had excellent soft magnetic properties of 4πMs=2.4 T, HC <80 A/m. However, the thickness of a recording head was 2μm, and Hc increased as thickness increased. In order to reduce the Hc, the sputtering power was raised from 200 W to 1000 W to reduce the grain size. 2μm Fe-N thin films were vacuum annealed under the same condition, when the N content was in the range of 5.9-8.5 at. pct, the thin films kept its excellent magnetic properties of 4πMs=2.2 T, HC <80 A/m. The properties of the films meet the need of a recording head material used in the dual-element GMR/inductive heads.展开更多
Fe-N thin films were fabricated on both 100Si and NaCl substrates by RF magnetron sputtering under low nitrogen partial pressure. The microstructure and magnetic properties of Fe-N thin films were investigated with th...Fe-N thin films were fabricated on both 100Si and NaCl substrates by RF magnetron sputtering under low nitrogen partial pressure. The microstructure and magnetic properties of Fe-N thin films were investigated with the increase of the substrate temperature （Ts） and the annealing temperature （Ta）. It is more difficult for nitrogen atoms to enter the Fe lattice under higher Ts above 150℃. The phase evolution is visible at higher Ta above 200℃. The phase transformation of α＇＇-Fe16N2 occurred at 400℃. The change of crystal size with Ta was clearly visible from bright and dark field images. The clear high-resolution electron microscope （HREM） images of 110α, 111γ＇, 112α＇＇, and 200α＇＇ phases were observed. The interplanar distances from TEM （transmission electron microscope） and HREM match the calculated values very well. From the results of the vibrating sample magnetometer （VSM）, the good magnetic properties of Fe-N films were obtained at 150℃ of Ts and 200℃ of Ta, respectively.展开更多
The segregation behavior of α-Fe particles in Cu-Fe film prepared by magnetron sputtering was studied by X-ray scattering and X-ray diffraction. The results show that the roughness of the film surface increases with ...The segregation behavior of α-Fe particles in Cu-Fe film prepared by magnetron sputtering was studied by X-ray scattering and X-ray diffraction. The results show that the roughness of the film surface increases with the sputtering time increasing. The as-sputtered films are super saturation solid solution of Cu-Fe. After annealing at 500℃, α-Fe particle can be segregated from the Cu matrix. The orientations α-Fe particles in the annealed film without magnetic field are random. But the clear texture of α-Fe particles in the annealed film with magnetic field is formed, and the 〈001〉 direction of α-Fe particles tends to be parallel to the magnetic field direction.展开更多
Cyclic voltammetry and chronoamperometry were used to investigate theelectrochemical behavior of Pr^(3+) ions in a system of 0.01 mol centre dot dm^(-3) Pr(CH_3SO_3)_3 +0.01 mol centre dot dm^(-3) FeCl_2 + 3.0 mol cen...Cyclic voltammetry and chronoamperometry were used to investigate theelectrochemical behavior of Pr^(3+) ions in a system of 0.01 mol centre dot dm^(-3) Pr(CH_3SO_3)_3 +0.01 mol centre dot dm^(-3) FeCl_2 + 3.0 mol centre dot dm^(-3) urea + DMSO on a R electrode. Someelectrochemical parameters were measured. Potentiostatic depositions between -1.6 and -2.4 V wereapplied to deposit Pr-Fe films in urea-DMSO mixed solution. The Pr content in the alloy films was inthe range of 34.89 wt. percent to 37.15 wt. percent. The Pr-Fe alloy films are proven to beamorphous by XRD (X-ray diffraction).展开更多
The micro-laminated （ZrO2-Y2O3）/（Al2O3-Y2O3） composite films were prepared on the surface of Fe-13Cr alloy by an electrochemical process and a sintering process alternately. High-resolution field emission scanning...The micro-laminated （ZrO2-Y2O3）/（Al2O3-Y2O3） composite films were prepared on the surface of Fe-13Cr alloy by an electrochemical process and a sintering process alternately. High-resolution field emission scanning electron microscopy （FE-SEM） was used to characterize the laminated films, indicating that the micro-laminated （ZrO2-Y2O3）] （Al2O3-Y2O3） films have nano-structures. SEM, EDS and mass gain measurement were adopted to study the oxidation resistance of films on Fe-13Cr alloy. It is proved that such micro-laminated films are more effective than ZrO2-Y2O3 or Al2O3-Y2O3 films to resist the oxidation of the alloy, and the oxidation resistance is increased with increasing layers in micro-laminated films. These beneficial effects can be contributed to the mechanism, by which such micro-laminated （ZrOE- YEO3）/（Al2O3-Y2O3） composite film combines all the beneficial effects and overcomes all the disadvantages of both ZrOE- Y2O3 film and Al2O3-Y2O3 film during oxidation of alloy.展开更多
文摘The cyclic voltammetry and potential step methods were used to investigate the electrochemical behavior of Fe 2+ and La 3+ in FeCl 2 LiCl DMSO and LaCl 3 LiCl DMSO systems on Pt, Cu and Ni cathodes. The electroreduction of Fe 2+ to Fe is irreversible in one step,while the electroreduction of La 3+ to La is quasi reversible. The diffusion coefficient of La 3+ in LaCl 3 LiCl DMSO system at 298 K was 3 1×10 -6 cm 2·s -1 . The diffusion coefficient and transfer coefficient of Fe 2+ in FeCl 2 LiCl DMSO system at 298 K were 2 54×10 -6 cm 2·s -1 and 0 24, respectively. La Fe alloy films containing La from 22 7% to 37 1% (mass fraction) were prepared by potentiostatic electrolysis on Cu substrates at a deposition potential from -1 750 to -2 450 V (vs SCE). The fine La Fe alloy films were also obtained by pulse electrolysis at a pulse current densities from 2 to 6 mA·cm -2 . The surfaces of these alloy films are smooth, adhesive and uniform, and have metallic luster.
基金Project supported by the National Natural Science Foundation for Young Scientists of China (Grant No. 10702058)the China Postdoctoral Science Foundation (Grant No. 20090451100)
文摘The physical vapour deposition of Ni atoms on α-Fe（001） surface under different deposition temperatures were simulated by molecular dynamics to study the intermixing and microstructure of the interracial region. The results indicate that Ni atoms hardly penetrate into Fe substrate while Fe atoms easily diffuse into Ni deposition layers. The thickness of the intermixing region is temperature-dependent, with high temperatures yielding larger thicknesses. The deposited layers are mainly composed of amorphous phase due to the abnormal deposition behaviour of Ni and Fe. In the deposited Ni-rich phase, the relatively stable metallic compound B2 structured FeNi is found under high deposition temperature conditions.
基金National Science Council of Taiwan-China! grant number NSC8&0208-M007-083PC.
文摘The Fe_3O_4/Fe/Fe_3O_4 (MIM) tri-layer films (200 nm/12-93 nm/200 um) were prepared on Si(100) by DC-magnetron reactive-sputtering followed by air- or vacuum-annealing at 280-400℃ for 1.5 h, respectively. Magnetic properties and phases under different sandwich and annealing conditions were studied. In MIM structure, the incorporation of the interlayer iron does increase the magnetization measured under 8 kOe (M_8K), but reduce coercivity (H_c). The H_c of asdeposited films decreases from 354 Oe to 74 Oe; while M_8K increases from 254 to 392 emu/cc. By annealing in air, the whole MIM tri-layer film becomes γ-F_e2O_3, H_c is about 550 O_e and M_8K is around 250 emu/cc. The coercivity mechanism of as-deposited and annealed MIM trilayer films belongs to domain-wall pinning type. δM plots show that when the interlayer Fe thickness is 12 um, the Fe and Fe_3O_4 layers are decoupled in the as-deposited and annealed states; while it is coupled in the as deposited state when the Fe thickness increases to 23 um. Vacuum annealing of the MIM films leads to increase in both coercivity and magnetization, and to enhance the exchange coupling between layers.
文摘Permeability characteristics of sputtered soft magnetic Fe40Co40B20 thin films are investigated in the range of O. 5 to 5 GHz by a shortened microstrip transmission line perturbation method. Excellent microwave permeability is achieved at 0.4 Pa argon pressure： fr is 3.32 GHz, the real and imaginary part of permeability at 0.5 GHz are 104 and 61, respectively. In addition, the thickness effect on permeability is also studied. The minimum damping can be achieved at the thinnest film. Different sources contributed to in-plane anisotropy are discussed briefly. The deviation between the peak frequency of the imaginary part and the zero-crossing frequency of the real part of permeability is also presented.
基金supported by the National NaturalScience Foundation of China (Grant No. 50871103).
文摘Precursive iron films with different grain sizes were prepared by magnetron sputtering on substrates heated at different temperatures. The iron films were sulfurized at 673 K for 20 h to form pyrite films. The structural and electrical characters were determined. High substrate temperatures produce large crystallites in the precursive iron films. The pyrite films are composed of a surface layer with coarse columnar grains and a bottom layer with fine equiaxed grains. With the increase of iron grain scale, the carrier concentration decreases and the carrier mobility increases. The electrical resistivity of the pyrite films increases to a maximum in the precursive iron films with increasing the grain size to about 3g nm. Sufficient formation and growth of iron grains result in improved crystallinity and high continuity of the pyrite films. The crystal defect density, transformation stress level and atom diffusion behavior are responsible for the characteristics of the electrical properties dependent on the crystallinity and continuity of the pyrite films or the crystallizing status of the precursive iron films.
文摘Ni80Fe20/Ni48Fe12Cr40 bilayer films and Ni80Fe20 monolayer films were deposited at room temperature on SiO2/Si（100） substrates by electron beam evaporation. The influence of the thickness of the Ni48Fe12Cr40 underlayer on the structure, magnetization, and magnetoresistance of the Ni80Fe20/Ni48Fe12Cr40 bilayer film was investigated. The thickness of the Ni48Fe12Cr40 layer varied from about 1 nm to 18 nm while the Ni80Fe20 layer thickness was fixed at 45 nm. For the as-deposited bilayer films the introducing of the Ni48Fe12Cr40 underlayer promotes both the （111） texture and grain growth in the Ni80Fe20 layer. The Ni48Fe12Cr40 underlayer has no significant influence on the magnetic moment of the Ni80Fe20/Ni48Fe12Cr40 bilayer film. However, the coercivity of the bilayer film changes with the thickness of the Ni48Fe12Cr40 undedayer. The optimum thickness of the Ni48Fe12Cr40 underlayer for improving the anisotropic magnetoresistance effect of the Ni80Fe20/Ni48Fe12Cr40 bilayer film is about 5 nm. With a decrease in temperature from 300 K to 81 K, the anisotropic magnetoresistance ratio of the Ni80Fe20 （45 nm）/Ni48Fe12Cr40 （5 nm） bilayer film increases linearly from 2.1% to 4.8% compared with that of the Ni80Fe20 monolayer film from 1.7% to 4.0%.
文摘In the present work,ferrite(Fe)doped TiO_(2)thin films with different volume percentage(vol%)were synthesized using a spray pyrolysis technique.The effect of Fe doping on structural properties such as crystallite size,texture coefficient,microstrain,dislocation densities etc.were evaluated from the X ray diffratometry(XRD)data.XRD data revealed a polycrystalline anatase TiO_(2)phase for sample synthesized up to 2 vol%and mixed anatase and rutile crystalline phase for sample synthesized at 4 vol%Fe doped TiO_(2).The crystalline size was observed to decrease with increase in Fe dopant vol%and also other structural parameters changes with Fe dopant percentage.In the present work,electrical resistance was observed to decrease with a rise in Fe dopant vol%and temperature of the sample.Thermal properties like temperature coefficient of resistance and activation energy also showed strong correlation with Fe dopant vol%.Humidity sensing properties of the synthesized sample altered with a change in Fe dopant vol%.In the present paper,maximum sensitivity of about 88.7%for the sample synthesized with 2 vol%Fe doped TiO_(2)and also the lowest response and recovery time of about 52 and 3 s were reported for the same sample.
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This work was financially supported by the National High-Tech Research and Development Program (No.2003AA302510) and the Beijing Municipal Science and Technology Program (No.D0405003040121).
文摘A Fe-Ni soft magnetic film was prepared in sulphate solution by electroplating. The influences of the molar ratio of n[Fe2+]/n[Ni2+], current density, bath temperature, pH and L-ascorbic acid concentration on magnetic properties of Fe-Ni alloy film were investigated. The results show that the saturated flux density(BS) of the film increases initially and decreases after it reaches the specific value with the increase of n[Fe2+]/n[Ni2+] molar ratio, current density, bath temperature and pH. However, the relationship between L-ascorbic acid concentration and BS keeps linear. It is observed that the coercive force(Hc) is enhanced with the increase of n[Fe2+]/n[Ni2+] molar ratio, current density and pH. By comparison, when the bath temperature increases, Hc always decreases. With the increase of L-ascorbic acid concentration, the coercive force increases initially and then decreases.
文摘The nanotitanium dioxide （TiO2） photocatalytic and porous ceramic filtering technique is one of the advanced methods to effectively treat organic wastewater. The TiO2 sol doped with Fe^3＋ ions was prepared by sol-gel processing. The influences of the process conditions of coating nanophotocatalytic material- Fe^3＋-TiO2 film on the surface of porous ceramic filter by dipping-lift method on the performance of porous ceramic filter were studied. The porous ceramic filters have two functions at the same time, filtration and photocatalytic degradation. The results of this study showed that the pH and viscosity of the sol, amount of Fe^3＋ ions doped as well as the coating times greatly affect the quality of coating film, the performance parameters and the photocatalytic activity of the porous ceramic filter. When the pH of the sol is 3-4, the viscosity is about 6 mPa.S, the amount of doped Fe^3＋ ions is about 2.0 g/L, the porous ceramic filter has been shown to have the best filtering performance and photocatalytic activity. In this condition, the porosity of porous ceramic is about 42.5%, the pore diameter is 8-10μm. The degradation of methyl-orange is 74.76% under lighting for 120 rain.
基金supported by the National Natural Science Foundation of China under grant No.19890310
文摘200 nm thick Fe-N magnetic thin films were deposited on glass substrates by RF sputtering. The as-deposited films have high saturation magnetization but their coercivity is also higher than what is needed Therefore it is very important to reduce coercivity. The samples were vacuum annealed at 250℃ under 12000 A/m magnetic field. When the N content was in the range of 5-7 at. pct, the thin films consisted of α' +α' after heat treatment and had excellent soft magnetic properties of 4πMs=2.4 T, HC <80 A/m. However, the thickness of a recording head was 2μm, and Hc increased as thickness increased. In order to reduce the Hc, the sputtering power was raised from 200 W to 1000 W to reduce the grain size. 2μm Fe-N thin films were vacuum annealed under the same condition, when the N content was in the range of 5.9-8.5 at. pct, the thin films kept its excellent magnetic properties of 4πMs=2.2 T, HC <80 A/m. The properties of the films meet the need of a recording head material used in the dual-element GMR/inductive heads.
基金supported by the National Natural Science Foundation of China(No.50674071)Tianjin Natural Science Foundation of China(No.06YFJZJC01300)+1 种基金the Program for New Century Excellent Talents in University(NCET-06-0245)the Platform Project of Tianjin for Innovation in Science and Technology and Environmental Construction(No.06TXTJJC13900).
文摘Fe-N thin films were fabricated on both 100Si and NaCl substrates by RF magnetron sputtering under low nitrogen partial pressure. The microstructure and magnetic properties of Fe-N thin films were investigated with the increase of the substrate temperature （Ts） and the annealing temperature （Ta）. It is more difficult for nitrogen atoms to enter the Fe lattice under higher Ts above 150℃. The phase evolution is visible at higher Ta above 200℃. The phase transformation of α＇＇-Fe16N2 occurred at 400℃. The change of crystal size with Ta was clearly visible from bright and dark field images. The clear high-resolution electron microscope （HREM） images of 110α, 111γ＇, 112α＇＇, and 200α＇＇ phases were observed. The interplanar distances from TEM （transmission electron microscope） and HREM match the calculated values very well. From the results of the vibrating sample magnetometer （VSM）, the good magnetic properties of Fe-N films were obtained at 150℃ of Ts and 200℃ of Ta, respectively.
文摘The segregation behavior of α-Fe particles in Cu-Fe film prepared by magnetron sputtering was studied by X-ray scattering and X-ray diffraction. The results show that the roughness of the film surface increases with the sputtering time increasing. The as-sputtered films are super saturation solid solution of Cu-Fe. After annealing at 500℃, α-Fe particle can be segregated from the Cu matrix. The orientations α-Fe particles in the annealed film without magnetic field are random. But the clear texture of α-Fe particles in the annealed film with magnetic field is formed, and the 〈001〉 direction of α-Fe particles tends to be parallel to the magnetic field direction.
文摘Cyclic voltammetry and chronoamperometry were used to investigate theelectrochemical behavior of Pr^(3+) ions in a system of 0.01 mol centre dot dm^(-3) Pr(CH_3SO_3)_3 +0.01 mol centre dot dm^(-3) FeCl_2 + 3.0 mol centre dot dm^(-3) urea + DMSO on a R electrode. Someelectrochemical parameters were measured. Potentiostatic depositions between -1.6 and -2.4 V wereapplied to deposit Pr-Fe films in urea-DMSO mixed solution. The Pr content in the alloy films was inthe range of 34.89 wt. percent to 37.15 wt. percent. The Pr-Fe alloy films are proven to beamorphous by XRD (X-ray diffraction).
文摘The micro-laminated （ZrO2-Y2O3）/（Al2O3-Y2O3） composite films were prepared on the surface of Fe-13Cr alloy by an electrochemical process and a sintering process alternately. High-resolution field emission scanning electron microscopy （FE-SEM） was used to characterize the laminated films, indicating that the micro-laminated （ZrO2-Y2O3）] （Al2O3-Y2O3） films have nano-structures. SEM, EDS and mass gain measurement were adopted to study the oxidation resistance of films on Fe-13Cr alloy. It is proved that such micro-laminated films are more effective than ZrO2-Y2O3 or Al2O3-Y2O3 films to resist the oxidation of the alloy, and the oxidation resistance is increased with increasing layers in micro-laminated films. These beneficial effects can be contributed to the mechanism, by which such micro-laminated （ZrOE- YEO3）/（Al2O3-Y2O3） composite film combines all the beneficial effects and overcomes all the disadvantages of both ZrOE- Y2O3 film and Al2O3-Y2O3 film during oxidation of alloy.
