Mg-Ni thin films for nickel-metal hydride (Ni-MH) battery negative electrode were prepared on three different substrates by using magnetron sputtering with compacted Ni and Mg mixture powder. The microstructure of Mg-...Mg-Ni thin films for nickel-metal hydride (Ni-MH) battery negative electrode were prepared on three different substrates by using magnetron sputtering with compacted Ni and Mg mixture powder. The microstructure of Mg-Ni thin films deposited on the glass and the Ni foil substrate respectively was studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the Mg-Ni thin films were in amorphous structure and the composition of the thin film was homogeneous. Electrochemical measurement show the discharge capacity of the thin film negative electrode deposited on the foam Ni substrate was 284.8mAh/g in 6M alkaline electrolyte and the internal resistance was much lower than that of the electrode prepared by the ball-milled powder during the charge-discharge cycle.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
Nanometer-scale thin film of Ni supported on glassy carbon (nm-Ni/GC) was prepared by electrochemical deposition through cyclic voltammetry (CV). The properties of nm-Ni/GC were studied by electrochemical in situ FTIR...Nanometer-scale thin film of Ni supported on glassy carbon (nm-Ni/GC) was prepared by electrochemical deposition through cyclic voltammetry (CV). The properties of nm-Ni/GC were studied by electrochemical in situ FTIR reflection spectroscopy using CO adsorption as probe reaction. It has revealed that the nm-Ni/GC exhibits almormal infrared effects (AIREs). The study has extended the inves-tigation of the AIREs that we have discovered initially on nanostructured film materials of platinum group metals and alloys to nanostructured film materials of iron group metals.展开更多
NiCr micron-resistor was designed and prepared by magnetron sputtering and lithography on the substrate of silicon with different powers. It is found that there exists a big gap in the TCR between the annealed group a...NiCr micron-resistor was designed and prepared by magnetron sputtering and lithography on the substrate of silicon with different powers. It is found that there exists a big gap in the TCR between the annealed group and the un-annealed group. A series of tests were made to figure out the reasons lying behind the gap in the TCR between the annealed group and the un-annealed group. UV reflection results show that there is no increase in the concentration of free electrons after annealing. However, the data obtained from XRD reveal that the annealing does not have an obvious influence on the strain of thin films, but really increases the grain size of thin films. Therefore, the grain boundary scattering plays a dominant role in explaining the obvious difference in the TCR. Finally through appropriate methods, a micron-resistor for heating-up with a low TCR value was obtained.展开更多
NiMnGaferromagnetic shape memory thin film was deposited onto Al foil using r.f.magnetron sputtering technique.The crystallization behavior of the film was investigated by XRD and DSC.The activation energy of crystall...NiMnGaferromagnetic shape memory thin film was deposited onto Al foil using r.f.magnetron sputtering technique.The crystallization behavior of the film was investigated by XRD and DSC.The activation energy of crystallization of the film was calculated by Kissinger’s method.The results show that the crystallization temperature of NiMnGafree-standing thin film in martensite state is 372 ℃,and the activation energy of crystallization is about 191.9 kJ·mol-1.展开更多
Microstructure and phase transformation behaviors of the film annealed at different temperatures were studied by X-ray diffractometry （XRD）, transmission electron microscopy and differential scanning calorimeter （...Microstructure and phase transformation behaviors of the film annealed at different temperatures were studied by X-ray diffractometry （XRD）, transmission electron microscopy and differential scanning calorimeter （DSC）. Also tensile tests were examined. For increasing annealed temperature, multiple phase transformations, transformations via a B19-phase or direct martensite/austenite transformtion are observed. The TiNiPd thin film annealed at 750℃ had relatively uniform martensite/austenite transformtion and shape memory effect. Martensite/austenite transformtion was also found in strain-temperature curves. Subsequent annealing at 450℃ had minor effect on transformation temperatures of Ti-Ni-Pd thin films but resulted in more uniform transformation and improved shape memory effect.展开更多
The effect of surface roughness of aluminum oxide (95%) substrate on the properties of Ni-Cr alloy thin film is studied.The thin films are prepared on the substrates with different roughness by using magnetron sputter...The effect of surface roughness of aluminum oxide (95%) substrate on the properties of Ni-Cr alloy thin film is studied.The thin films are prepared on the substrates with different roughness by using magnetron sputtering.The micro-structure,adhesive and electrical properties of the thin films were investigated by using scanning electron microscopy,scratch method and four-probe method.The burst voltage and current of the thin film transducers with different substrates were measured according to D-optimization method.The results show that the particle size,structural defect,resistivity and adhesion strength of the thin film increase with the increase of the substrate roughness.The difference among the burst time of the samples with difference substrate roughness gradually decreases with the increase of stimulation amount.The burst time is approximate to 20 μs in the charging voltage of 37 V.展开更多
Chemical bath deposition technique has been used to deposit Ni-doped Sb2S3 thin films onto glass substrate. Doping was carried out by adding 1, 3 and 5 wt% of Ni. Bath temperature was kept as 10℃ and films were annea...Chemical bath deposition technique has been used to deposit Ni-doped Sb2S3 thin films onto glass substrate. Doping was carried out by adding 1, 3 and 5 wt% of Ni. Bath temperature was kept as 10℃ and films were annealed at 250℃ under vacuum. Polycrystalline nature of films with an orthorhombic phase was analyzed by X-ray diffraction technique. Scanning electron microscopy was used for morphological study which shows that grains are spherical. Optical measurements using transmittance data indicated that films have a direct band gap of 1.00 - 2.60 eV with an absorption coefficient of ~104 cm<sup>-1</sup> in visible range. The average value of electrical conductivity was calculated as 1.66, 1.11 and 1.06 (Ω·cm)<sup>-1</sup> for as-deposited films and 1.90, 2.08 and 1.15 (Ω·cm)<sup>-1</sup> for annealed films while refractive indices were found as 2.18 - 3.38 and 1.91 - 3.74 respectively. The obtained films can be used for solar cell applications due to their good absorbing properties like higher absorption coefficient and refractive index values.展开更多
采用动态蒙特卡罗(kinetic Monte Carlo,简称KMC)方法研究物理气相沉积(physical vapor deposition,简称PVD)制备Ni薄膜过程中入射角度对薄膜微观结构的影响。该KMC模型中既包括入射原子与表面之间的碰撞,又包括被吸附原子的扩散。模拟...采用动态蒙特卡罗(kinetic Monte Carlo,简称KMC)方法研究物理气相沉积(physical vapor deposition,简称PVD)制备Ni薄膜过程中入射角度对薄膜微观结构的影响。该KMC模型中既包括入射原子与表面之间的碰撞,又包括被吸附原子的扩散。模拟中用动量机制确定被吸附原子在表面上的初始构型,用分子稳态(molecular statics,简称MS)计算方法计算扩散模型中跃迁原子的激活能。对于模拟结果,采用表面粗糙度和堆积密度作为沉积构型评价指标。研究结果表明:当沉积速率是5μm/min,基板温度是300K和500K时,表面粗糙度和堆积密度曲线在入射角度等于35?时出现拐点;入射角度小于35?时,入射角度增大对表面粗糙度增加和堆积密度减小的影响很少;但是入射角度大于35?时,随入射角度增大表面粗糙度迅速增加、堆积密度迅速减小。另外,当基板温度是300K时,入射角度对薄膜微观结构的影响程度大于基板温度为500K时的影响程度。说明高基板温度促使原子更加充分地扩散,从而能削弱自阴影效应的作用。但是,在保证足够高基板温度和合理沉积速率的情况下,入射角度过大同样不利于致密结构形成。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.59925102,50131040,2002CCA02300)a project granted from the CityU of HK Research Committee(Project No.7001088).
文摘Mg-Ni thin films for nickel-metal hydride (Ni-MH) battery negative electrode were prepared on three different substrates by using magnetron sputtering with compacted Ni and Mg mixture powder. The microstructure of Mg-Ni thin films deposited on the glass and the Ni foil substrate respectively was studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the Mg-Ni thin films were in amorphous structure and the composition of the thin film was homogeneous. Electrochemical measurement show the discharge capacity of the thin film negative electrode deposited on the foam Ni substrate was 284.8mAh/g in 6M alkaline electrolyte and the internal resistance was much lower than that of the electrode prepared by the ball-milled powder during the charge-discharge cycle.
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.
文摘Nanometer-scale thin film of Ni supported on glassy carbon (nm-Ni/GC) was prepared by electrochemical deposition through cyclic voltammetry (CV). The properties of nm-Ni/GC were studied by electrochemical in situ FTIR reflection spectroscopy using CO adsorption as probe reaction. It has revealed that the nm-Ni/GC exhibits almormal infrared effects (AIREs). The study has extended the inves-tigation of the AIREs that we have discovered initially on nanostructured film materials of platinum group metals and alloys to nanostructured film materials of iron group metals.
文摘NiCr micron-resistor was designed and prepared by magnetron sputtering and lithography on the substrate of silicon with different powers. It is found that there exists a big gap in the TCR between the annealed group and the un-annealed group. A series of tests were made to figure out the reasons lying behind the gap in the TCR between the annealed group and the un-annealed group. UV reflection results show that there is no increase in the concentration of free electrons after annealing. However, the data obtained from XRD reveal that the annealing does not have an obvious influence on the strain of thin films, but really increases the grain size of thin films. Therefore, the grain boundary scattering plays a dominant role in explaining the obvious difference in the TCR. Finally through appropriate methods, a micron-resistor for heating-up with a low TCR value was obtained.
基金This work is financially supported by the National Natural Science Foundation of China ( No 50531020)
文摘NiMnGaferromagnetic shape memory thin film was deposited onto Al foil using r.f.magnetron sputtering technique.The crystallization behavior of the film was investigated by XRD and DSC.The activation energy of crystallization of the film was calculated by Kissinger’s method.The results show that the crystallization temperature of NiMnGafree-standing thin film in martensite state is 372 ℃,and the activation energy of crystallization is about 191.9 kJ·mol-1.
基金supported by Science&Technology Commission of Shanghai Municipality(STCSM),China(No.02DJ14042)the Key Project of Chinese Ministry of Education(No.0307).
文摘Microstructure and phase transformation behaviors of the film annealed at different temperatures were studied by X-ray diffractometry （XRD）, transmission electron microscopy and differential scanning calorimeter （DSC）. Also tensile tests were examined. For increasing annealed temperature, multiple phase transformations, transformations via a B19-phase or direct martensite/austenite transformtion are observed. The TiNiPd thin film annealed at 750℃ had relatively uniform martensite/austenite transformtion and shape memory effect. Martensite/austenite transformtion was also found in strain-temperature curves. Subsequent annealing at 450℃ had minor effect on transformation temperatures of Ti-Ni-Pd thin films but resulted in more uniform transformation and improved shape memory effect.
文摘The effect of surface roughness of aluminum oxide (95%) substrate on the properties of Ni-Cr alloy thin film is studied.The thin films are prepared on the substrates with different roughness by using magnetron sputtering.The micro-structure,adhesive and electrical properties of the thin films were investigated by using scanning electron microscopy,scratch method and four-probe method.The burst voltage and current of the thin film transducers with different substrates were measured according to D-optimization method.The results show that the particle size,structural defect,resistivity and adhesion strength of the thin film increase with the increase of the substrate roughness.The difference among the burst time of the samples with difference substrate roughness gradually decreases with the increase of stimulation amount.The burst time is approximate to 20 μs in the charging voltage of 37 V.
文摘Chemical bath deposition technique has been used to deposit Ni-doped Sb2S3 thin films onto glass substrate. Doping was carried out by adding 1, 3 and 5 wt% of Ni. Bath temperature was kept as 10℃ and films were annealed at 250℃ under vacuum. Polycrystalline nature of films with an orthorhombic phase was analyzed by X-ray diffraction technique. Scanning electron microscopy was used for morphological study which shows that grains are spherical. Optical measurements using transmittance data indicated that films have a direct band gap of 1.00 - 2.60 eV with an absorption coefficient of ~104 cm<sup>-1</sup> in visible range. The average value of electrical conductivity was calculated as 1.66, 1.11 and 1.06 (Ω·cm)<sup>-1</sup> for as-deposited films and 1.90, 2.08 and 1.15 (Ω·cm)<sup>-1</sup> for annealed films while refractive indices were found as 2.18 - 3.38 and 1.91 - 3.74 respectively. The obtained films can be used for solar cell applications due to their good absorbing properties like higher absorption coefficient and refractive index values.
文摘用电化学方法制备Ag3PO4/Ni薄膜,以扫描电子显微镜(SEM)、X射线衍射(XRD)和紫外-可见漫反射光谱(UV-Vis DRS)对薄膜的表面形貌、晶相结构、光谱特性及能带结构进行了表征,以罗丹明B为模拟污染物对薄膜的光催化活性和稳定性进行了测定,采用向溶液中加入活性物种捕获剂的方法对薄膜光催化降解机理进行了探索。结果表明:最佳工艺下制备的Ag3PO4/Ni薄膜具有致密的层状表面结构,是由多晶纳米颗粒构成的薄膜。薄膜具有较高的光催化活性和突出的光催化稳定性,可见光下催化作用60 min,薄膜光催化罗丹明B的降解率是多孔P25 Ti O2/ITO纳米薄膜(自制)的2.3倍;在保持薄膜光催化活性基本不变的前提下可循环使用6次。给出了可见光下薄膜光催化降解罗丹明B的反应机理。
文摘采用电化学方法制备Ag3PO4/Ni薄膜,以扫描电镜(SEM)、X射线衍射(XRD)和紫外-可见漫反射光谱(UV-Vis DRS)对薄膜的表面形貌、晶相结构、光谱特性及能带结构进行表征,以罗丹明B为模拟污染物对薄膜的光电催化活性和稳定性进行测定,采用向溶液中加入活性物种捕获剂和通氮除氧方法对薄膜的光催化降解机理进行探索,并提出光电催化降解罗丹明B的反应机理。结果表明:最佳工艺下制备的Ag3PO4/Ni薄膜具有致密的层状表面结构,是由多晶纳米颗粒构成的薄膜。该薄膜具有显著的光电催化活性,在最佳阳极偏压下,光电催化罗丹明B的降解率是多孔P25 Ti O2/ITO薄膜的6.69倍;相对于未加偏压的光催化,降解率提高了5.34倍,并且具有突出的光电协同效应。同时,该薄膜具有优异的光催化和光电催化稳定性。在0.1 V阳极偏压下,可使光催化稳定性提高近一倍。
