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In recent years, a reduction in weight of materials is highly desirable in the fields of transport industry and information technology devices. Magnesium (Mg) alloys have excellent physical and mechanical properties such as low density, good electromagnetic shielding, and high strength/weight ratio. Unfortunately, they have a great issue that is low corrosion. Thus, it is very important to develop surface treatment technologies to improve the corrosion resistance of magnesium alloys. Many surface treatments such as chemical conversion, anodic oxidization, and electroplating have been developed. However, there processes require multi-step pretreatments and waste liquid treatments. Thus, the development of a simple, easy, and low-cost surface treatment is highly desirable. In this paper, we report a novel preparation method of anticorrosive film on Mg alloy by steam coating and the corrosion resistance of the film. The prepared films were characterized by XRD, SEM, EDX, and electrochemical measurements. Polarization curve measurements demonstrated that the Ecorr and icorr values were found to be most positive potential and lowest current density in all the samples, indicating that the sample had best corrosion resistant performance.

The effect of high densities of dislocations on the formation behavior of nanoscale clusters (nanoclusters), which are formed during natural aging at room temperature and the pre-aging at ~373 K in a 6000 series aluminum alloy, was investigated by atom probe tomography. Cold rolling was applied to modify the formation behavior and/or the characteristics of the two types of nanoclusters and also the precipitation sequence, which involve a strengthening phase (˝) to improve the bake-hardening (BH) response for auto body panels. Cold rolling to a 5% deformation accelerates the preferential formation of nanocluster at 373K along dislocations in addition to homogeneous nucleation in the crystal grains. Atom probe tomography demonstrate the heterogeneous formation of nanocluster during pre-aging at 373K. The ˝ phase shows the high growth rate at the same level of the as-quenched specimen in the cold rolled alloy on the aging curve at 443K. Cold rolling before pre-aging is an effective process to improve the BH response of the alloys.

We report the in situ synthesis of nitrogen-doped carbon nanoparticles (NCNPs) by a solution plasma process without the addition of metal catalysts. Organic liquid mixtures of benzene and pyrazine were used as the precursors for the synthesis. The nitrogen-doping content can be easily controlled by changing the amount of pyrazine in the precursor. The NCNPs synthesized from the solution plasma process exhibit a turbostratic structure with highly uniform nanoscale particles. The nitrogen atoms can be homogeneously incorporated into the entire carbon structure due to the in situ doping during the growth and formation of the carbon particles. The electrochemical activity toward the oxygen reduction reaction (ORR) of the NCNPs in an alkaline medium reveals the improvement in terms of both the onset potential and current density as the nitrogen-doping content increases. The enhanced ORR activity of the NCNPS is mainly attributed to the presence of pyridinic-N and graphitic-N bonding configurations. They also possess long-term durability and excellent tolerance to methanol crossover effects. The results obtained in this study have demonstrated that the solution plasma process has great potential for the synthesis of metal-free nitrogen-doped carbon electrocatalysts for the ORR. We expect that this approach can be extended to the synthesis of other heteroatom-doped carbonaceous materials for a broad range of research applications in energy conversion and storage.

Metal-air batteries are attracting increasing attention as a superior renewable energy conversion device due to their high performance and strong potential. However, the high cost and low stability of the current Pt catalyst is the main obstacle preventing wide industrial application. In this work, we applied a plasma process to fabricate aniline and a transition metals electrode (Fe, Co, Ni) as the carbon-nitrogen and the metal nanoparticle (NP) precursors, respectively, for selective metal/amino-N-doped carbon catalysts. All three as-synthesized catalysts exhibited dominant amino-N as the major C&ndash, N bonding state. In electrochemical testing, Co/amino-N-doped carbon showed positive E1/2 potential (0.83 V vs. Reversible Hydrogen Electrode (RHE)). In addition, the calculated electron transfer number (n) of Co/amino-N-doped carbon at 0.5 V vs. RHE was 3.81, which was only slightly less than that of commercial Pt/C (3.97). This superior performance of transition metal/amino-N-doped carbon promotes it as an economical oxygen reduction reaction (ORR) electrocatalyst to replace expensive Pt/C in metal-air batteries.

Anticorrosive molybdate films composed mainly of Mg(OH)2, MoO2, MoO3, and MgF2 were formed on magnesium alloy AZ31 by chemical conversion. The film had relatively compact surfaces and a thickness of approximately 800 nm. The XPS studies revealed that the film contained Mg, Al, Mo, O, P, S, and F elements. The corrosion resistant performances of the films were investigated by electrochemical measurements. The potentiodynamic polarization curves showed that anodic current densities and corrosion potential of the Mo coated AZ31 were lower and more positive than those of bare AZ31. The EIS measurement and appropriate equivalent circuit models revealed that the corrosion resistance was improved.

Halogen-doped carbon nanoparticles (CNPs) were synthesized by a simple one-step solution plasma process at room temperature using a mixture of benzene (C6H6) and organics containing halogen atoms as the precursors (i.e., hexafluorobenzene (C6F6), hexachlorobenzene (C6Cl6), and hexabromobenzene (C6Br6)). The experimental results demonstrated that halogen doping, especially F and Cl, could lead to more efficient removal of residual hydrogen compared to carbon synthesized with pure benzene. This phenomenon was related to the different binding energies between hydrogen and halogens to form hydrogen halides. Their crystallinity and morphology did not change and remained the same as non-doped carbon. The electrochemical evaluation of oxygen reduction reaction (ORR) activity in an alkaline solution revealed that halogen doping did not play a significant role in shifting the onset potential for the ORR, while a slight enhancement in diffusion limited current density was observed at high overpotentials. Moreover, the electron transfer number involved in the ORR process determined from the Koutecky–Levich plot at −0.6 V was found to increase for halogen-doped carbons in the following order: F-CNPs > Br-CNPs > Cl-CNPs > CNPs. The improved ORR performance of F-CNPs could reasonably be attributed to the synergistic effects of specific bonding states between the halogen and carbon, structural defects and surface functional groups. Our results confirmed the validity of using halogen doping to improve the ORR catalytic activity of CNPs.

Metal-free nitrogen-doped carbon materials are currently considered at the forefront of potential alternative cathode catalysts for the oxygen reduction reaction (ORR) in fuel cell technology. Despite numerous efforts in this area over the past decade, rational design and development of a new catalyst system based on nitrogen-doped carbon materials via an innovative approach still present intriguing challenges in ORR catalysis research. Herein, a new kind of nitrogen-doped carbon nanoparticle-carbon nanofiber (NCNP-CNF) composite with highly efficient and stable ORR catalytic activity has been developed via a new approach assisted by a solution plasma process. The integration of NCNPs and CNFs by the solution plasma process can lead to a unique morphological feature and modify physicochemical properties. The NCNP-CNF composite exhibits a significantly enhanced ORR activity through a dominant four-electron pathway in an alkaline solution. The enhancement in ORR activity of NCNP-CNF composite can be attributed to the synergistic effects of good electron transport from highly graphitized CNFs as well as abundance of exposed catalytic sites and meso/macroporosity from NCNPs. More importantly, NCNP-CNF composite reveals excellent long-term durability and high tolerance to methanol crossover compared with those of a commercial 20 wt % supported on Vulcan XC-72. We expect that NCNP-CNF composite prepared by this synthetic approach can be a promising metal-free cathode catalyst candidate for ORR in fuel cells and metal-air batteries.

A quartz crystal microbalance (QCM) chemical sensor coated with superhydrophobic film for detecting volatile organic compounds (VOCs) such as formaldehyde and toluene under ambient conditions was developed. The superhydrophobic film was deposited by means of microwave plasma enhanced chemical vapor deposition (MPECVD). The sensitivities of QCM sensor coated with superhydrophobic film to VOCs such as formaldehyde and toluene were investigated under ambient conditions. The sensitivity of the sensor to formaldehyde and toluene was considerably improved by the superhydrophobic surface modification. The surface modification promoted microscopic texturing to the film surface and thus increased the effective specific surface area of the sensor for the adsorption of formaldehyde and toluene. In addition, the adsorption of water molecules was minimized due to the superhydrophobic film deposited on the sensor surface, thus promoting the preferential adsorption of formaldehyde and toluene molecules on the QCM sensor coated with superhydrophobic film, compared to the conventional QCM sensor. Moreover, the adsorption mechanisms of formaldehyde–water and toluene–water molecules to the superhydrophobic film were discussed.

Anticorrosive multilayered films were successfully prepared on magnesium alloy AZ31 by chemical conversion treatment, followed by steam curing treatment. The crystal structures, chemical composition, surface morphologies, chemical bonding states of the film was characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and field emission scanning electron microscope (FE-SEM) measurements. All the films had thicknesses of ranging from 24 to 32 μm. The film had two layers that were composed of crystalline NH4MgPO4·H2O, Mg2PO4OH·3H2O, Mg(OH)2 and amorphous MgO. The outer layers include magnesium, oxygen, and phosphorous, and the inner layers include magnesium and oxygen. The corrosion resistant performances of the multilayered films in 5 wt% NaCl aqueous solution were investigated by electrochemical and gravimetric measurements. The potentiodynamic polarization curves revealed that the corrosion current density (jcorr) of all the film coated magnesium alloys decreased by more than four orders of magnitude as compared to that of the bare magnesium alloy, indicating that all the films had an inhibiting effect of corrosion reaction. Gravimetric measurements showed that the average corrosion rates obtained from the weight loss rates were estimated to be in the ranges of ca. 0.085–0.129 mm/y. American Society for Testing and Materials (ASTM) standard D 3359-02 cross cut tape test revealed that the adhesion of our anticorrosive multilayered film to the magnesium alloy surface was very good.

Anticorrosive composite films composed of amorphous or crystalline magnesium phosphate compounds and crystalline magnesium hydroxide were successfully prepared on magnesium alloy by a combination process of chemical conversion and steam-curing for the first time. The films had film thicknesses of ca. 30 μm and were composed of outer and inner layers. The corrosion resistances of the films coated magnesium alloy were investigated by electrochemical and gravimetric measurements. The films showed a much higher corrosive resistance than the uncoated one in corrosion tests.

The corrosion resistant performance and durability of the superhydrophobic surface on magnesium alloy coated with nanostructured cerium oxide film and fluoroalkylsilane molecules in corrosive NaCl aqueous solution were investigated using electrochemical and contact angle measurements. The durability of the superhydrophobic surface in corrosive 5 wt% NaCl aqueous solution was elucidated. The corrosion resistant performance of the superhydrophobic surface formed on magnesium alloy was estimated by electrochemical impedance spectroscopy (EIS) measurements. The EIS measurements and appropriate equivalent circuit models revealed that the superhydrophobic surface considerably improved the corrosion resistant performance of magnesium alloy AZ31. American Society for Testing and Materials (ASTM) standard D 3359-02 cross cut tape test was performed to investigate the adhesion of the superhydrophobic film to the magnesium alloy surface. The corrosion formation mechanism of the superhydrophobic surface formed on the magnesium alloy was also proposed.

Three-dimensional (3-D) Nb 2 O 5 nanotube layers with honeycomb structures were successfully synthesized using polystyrene (PS) microsphere templates and NbO x nanocrystals. A densely packed monolayer of monodisperse PS microspheres was deposited onto a silica glass substrate using the Langmuir–Blodgett film technique. NbO x nanocrystals were prepared via proton-exchange and exfoliation processes of highly crystalline, layered K 4 Nb 6 O 17 crystals obtained by flux-growth. The 3-D crystal layers were fabricated by coating the pastes containing NbO x nanosheets onto the PS microsphere templates, followed by a heating treatment in an electric furnace. During the heating process, the PS microsphere templates were thermally decomposed, and the NbO x nanosheets were transformed into Nb 2 O 5 nanotubes. As a result, transparent/colorless, nano-/micro-textured surfaces were formed on the silica glass substrates. The surface structure clearly varied depending on the nanosheet concentration of the pastes. The rough, solid surfaces modified with fluoroalkylsilane were found to be highly hydrophobic (water contact angle=148°). The 3-D nano-/micro-textures of the Nb 2 O 5 -layered surfaces enhanced their hydrophobicity. The highly hydrophobic surfaces were converted to ultrahydrophilic surfaces by photocatalytic oxidation using Nb 2 O 5 nanotube layers.

The design of color-tuned magnesium alloy with anticorrosive properties and damping capacity was created by means of a simple and inexpensive method. The vertically self-aligned nano- and microsheets were formed on magnesium alloy AZ31 by a chemical-free immersion process in ultrapure water at a temperature of 120 °C, resulting in the color expression. The color changed from silver with metallic luster to some specific colors such as orange, green, and orchid, depending on the immersion time. The color-tuned magnesium alloy showed anticorrosive performance and damping capacity. In addition, the colored surface with minute surface textures was modified with n-octadecyltrimethoxysilane (ODS), leading to the formation of color-tuned superhydrophobic surfaces. The corrosion resistance of the color-tuned superhydrophobic magnesium alloy was also investigated using electrochemical potentiodynamic measurements. Moreover, the color-tuned superhydrophobic magnesium alloy showed high hydrophobicity not just for pure water but also for corrosive liquids, such as acidic, basic, and some aqueous salt solutions. In addition, the American Society for Testing and Materials (ASTM) standard D 3359-02 cross cut tape test was performed to investigate the adhesion of the color-tuned superhydrophobic film to the magnesium alloy surface.

Highly crystalline, well-developed potassium titanoniobate (KTiNbO5 and KTi3NbO9) crystals were successfully grown at temperatures ranging from 700 to 1000 °C by a KCl flux cooling method. Colourless and transparent KTiNbO5 crystals with a smallest average size of 750 nm were grown at a relatively low temperature of 700 °C. The sizes of grown crystals were observed to greatly dependent on the holding temperature and solute concentration. HRTEM observations indicated that the flux-grown KTiNbO5 crystals were of high quality. The band gap energies of the fabricated KTiNbO5 and KTi3NbO9 crystals, as estimated from their absorption edges in UV-vis diffuse reflectance spectra, were approximately 3.54 and 3.35 eV, respectively. Furthermore, these crystals exhibited good photocatalytic activities under UV light irradiation. The photodecomposition of TCE gas occurred via a photocatalytic process under UV light irradiation. This study demonstrates that KCl flux cooling is an environmentally friendly and nature-mimetic process for growing high-quality, well-developed, and photocatalytic KTiNbO5 and KTi3NbO9 crystals.

A super-hydrophobic film was successfully deposited on magnesium alloy AZ31 by the microwave plasma-enhanced chemical vapor deposition (MPECVD) process. The film surface showed a static water contact angle of more than 150°. The hydrophobicity and root mean square roughness of the film surface increased with an increase in deposition time. The anticorrosion resistance of the deposited film was estimated by electrochemical impedance spectroscopy (EIS) measurements. The EIS measurements and appropriate equivalent circuit models revealed that the super-hydrophobic film considerably improved the anticorrosion resistant performance of magnesium alloy AZ31. The anticorrosion mechanism of the super-hydrophobic film was also considered. Moreover, the chemical stability of the super-hydrophobic film in acidic, neutral, and alkaline aqueous solutions was investigated. The super-hydrophobic film showed high chemical stability in acidic and neutral aqueous solutions.

We have developed a facile, simple, time-saving method of creating a superhydrophobic surface on a magnesium alloy by a simple immersion process at room temperature. First, a crystalline CeO(2) film was vertically formed on the magnesium alloy by immersion in a cerium nitrate aqueous solution for 20 min. The density of the crystals vertically with respect to the magnesium alloy increased with increasing immersion time. Next, the film were covered with fluoroalkylsilane (FAS: CF(3)(CF(2))(7)CH(2)CH(2)Si(OCH(3))(3)) molecules within 30 min by immersion in a toluene solution containing FAS and tetrakis(trimethylsiloxy)titanium (TTST: (CH(3))(3)SiO)(4)Ti). TTST was used as a catalyst to promote the hydrolysis and/or polymerization of FAS molecules. The FAS-coated CeO(2) film had a static contact angle of more than 150 degrees, that is, a superhydrophobic property. The shortest processing time for the fabrication of the superhydrophobic surface was 40 min. The contact angle hysteresis decreased with an increase in the immersion time in the cerium nitrate aqueous solution. The chemical stability of the superhydrophobic surface on magnesium alloy AZ31 was investigated. The average static water contact angles of the superhydrophobic surfaces after immersion in the solutions at pH 4, 7, and 10 for 24 h were found to be 139.7 +/- 2, 140.0 +/- 2, and 145.7 +/- 2 degrees, respectively. In addition, the chemical stability of the superhydrophobic surface in the solutions at pH ranging from 1 to 14 was also examined. The superhydrophobic surfaces had static contact angles of more than 142 degrees in the solutions at pH ranging from 1 to 14, showing that our superhydrophobic surface had a high chemical stability. Moreover, the corrosion resistance of the superhydrophobic surface on the magnesium alloy was investigated using electrochemical measurements.

Al alloys offer excellent physical and mechanical properties, such as a low density, high specific strength, and good ductility. However, their low corrosion resistance has restricted their application in corrosive environments. There is a need, therefore, for a novel coating technology that is capable of improving the corrosion resistance of Al alloys. In the present study, we examined a steam-based method of forming a corrosion-resistant film on Al alloys. Al-Mg-Si alloy was used as the substrate. The cleaned substrates were set in an autoclave with ultrapure water as the steam source and processed using different temperatures and holding times, resulting in the formation of anticorrosive films on the alloy. FE-SEM images of the film surfaces showed that plate-like nanocrystals were densely formed over the entire surface. XRD patterns indicated that the film was composed mainly of AlOOH crystals. The potentiodynamic polarization curves revealed that the corrosion current density of the film-coated substrates significantly decreased, and that the pitting corrosion was completely suppressed, indicating that the corrosion resistance of the Al-Mg-Si alloy was improved by the film formed by means of steam coating.

A novel anticorrosive film with a thickness of approximately 50 μm was successfully coated on an AZ31 magnesium alloy by chemical and low-heat treatments (50 °C). The film was a single-phase system of newberyite (MgHPO 4 •3H 2 O) having an orthorhombic crystal structure. The corrosion current density of the newberyite film coated on the AZ31 magnesium alloy decreased by more than two orders of magnitude as compared to that of the AZ31 magnesium alloy. The static water contact angle of the newberyite film was less than 10°. The average value of the scratch critical load for the newberyite coating was estimated to be approximately 15 mN.

The binary alkyl- and amino-terminated self-assembled monolayers (SAMs) composed of nano/micro-sized domains was prepared though a self-assembly technique. In addition, the wetting and electrostatic property of the binary SAMs was investigated by the analysis of the static and dynamic water contact angle and zeta-potentials measurement. The binary SAMs were also characterized by atomic force microscope (AFM), Kelvin probe force microscope (KPFM) and X-ray photoelectron spectroscopy (XPS). The domains on the binary SAMs were observed in topographic and surface potential images. The height of domain and the surface potential between octadecyltrichlorosilanes (OTS)-domain and n-(6-aminohexl)aminopropyl-trimethoxysilane (AHAPS)-SAM were about 1.1 nm and −30 mV. These differences of height and surface potential correspond to the ones between OTS and AHAPS. In XPS N 1s spectra, we confirmed the formation of binary SAMs by an amino peak observed at 399.15 eV. The dynamic and the static water contact angles indicated that the wetting property of the binary SAMs was depended on the OTS domain size. In addition, static water contact angles were measured under the conditions of different pH water and zeta-potential also indicated that the electrostatic property of the binary SAMs depended on OTS domain size. Thus, these results showed that the wetting and electrostatic property on the binary SAMs could be regulated by controlling the domain size.

The effect of reaction temperature on the self-organization and growth mechanism of octadecyltrichlorosilane (OTS) self-assembled monolayers (SAM) was investigated by atomic force microscopy (AFM), grazing incidence X-ray diffraction (GIXD) measurement, Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). OTS SAM was prepared by a liquid phase method and chemical vapor deposition. In the liquid phase method, OTS SAM was prepared in the temperature range from 5 to 40 °C. In the reaction temperature range from 5 to 30 °C, OTS molecules formed domain structures early in the growth process and grew two-dimensionally on SiO2 substrates. In addition, the crystalline peaks of GIXD measurements indicated that OTS SAM prepared at lower temperatures (5–30 °C) grew in the crystalline state. Thus, "self-organization" occurred under these conditions. However, OTS SAM prepared at 40 °C showed an amorphous structure. XPS and FT-IR spectra showed that the SiO2 peak increased while reaction temperature decreased. These results indicated that the formation of a siloxane bond between OTS molecules was important for the self-organization of the OTS monolayer. In addition, FT-IR measurement indicated that the packing density of the OTS monolayer prepared at lower temperatures was higher than that prepared at higher temperatures by chemical vapor deposition.

The effect of humidity on the self-organization and growth mechanism of octadecyltrichlorosilane (OTS) monolayers was investigated using an atomic force microscope (AFM), grazing incidence X-ray diffraction (GIXD), and Fourier transform IR spectroscopy (FT-IR). OTS self-assembled monolayers (SAMs) were prepared under humidity ranging from 5 to 80%. Under humidity ranging from 15 to 80%, OTS molecules produced domain structures early in the growth process that grew two-dimensionally on SiO2 substrates. Also, the crystalline peaks of the obtained from the GIXD measurement indicated that OTS-SAMs prepared under high humidity (15–80%) had grown in a crystalline state. Thus, "self-organization" occurred under these conditions. However, OTS-SAMs prepared under 5% humidity were in an amorphous structure. OTS-SAMs prepared at high humidity were denser than those prepared at low humidity. The domain size early in the growth process increased in proportion to the solution age. This shows that the reaction rate is governed by the hydrolysis of organosilane. On the other hand, solution age has no great influence on the density of the OTS-SAMs under conditions of more than 50% humidity.

A biomimetic super-hydrophobic/super-hydrophilic micropatterned template was successfully fabricated by microwave plasma-enhanced chemical vapor deposition (MPECVD) and vacuum ultraviolet (VUV) lithography. Water drops were selectively condensed on super-hydrophilic regions of the template. In the solution of pH 2.6, carboxyl-terminated fluorescent polystyrene spheres were sedimented on super-hydrophobic regions due to electrostatic attractive forces between negative -COO - and positive -CH 3 groups. Cu was also deposited densely on only super-hydrophobic regions through electroless plating. From these results, we revealed that the biomimetic super-hydrophobic/super-hydrophilic micropatterned template was used as site-selective chemical reaction field. © 2008 Elseiver B.V All rihgts reserved.

The adsorption behaviors of fibrinogen on the self-assembled monolayers (SAMs) with different chemical properties were investigated using an atomic force microscopy (AFM). AFM images indicated that the adsorption amounts of fibrinogen molecules increased with an increase of the surface hydrophobicity. High-resolution AFM imaging revealed that the fibrinogen conformations adsorbed on the SAM surface changed with dependent on the surface chemistry. The adsorption models of fibrinogen molecules adsorbed on SAM surfaces with different chemical properties were proposed based on the high-resolution AFM images.

Electrochemical scanning probe lithography (SPL) was carried out on a 1,7-octadiene (OD) monolayer directly attached to silicon. The chemical conversion of the OD-monolayer was investigated by Kelvin probe force microscopy (KPFM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and by an adsorption test of amino-modified fluorescent spheres. AFM and KPFM results indicated that the electrochemical reactions induced by SPL were governed by the bias voltage applied between the tip of the scanning probe microscope (SPM) and the substrate. XPS spectra indicated that the vinyl groups on the OD monolayer were oxidized and chemically converted into carboxyl groups at bias voltages of 1–2 V. At bias voltages of more than 3 V, OD molecules on the sample surface were decomposed and silicon oxide was formed on the surface. In addition, the formation of COOH groups was confirmed by the site-selective adsorption of amino-modified fluorescent spheres. However, XPS spectra for sample surfaces scanned at negative bias voltages showed no change since the peak was generally weak. However, KFM and AFM results indicated that at bias voltages of more than −1.5 V, cyclobutane rings formed.

An organic monolayer directly attached to silicon was prepared through a reaction between 1,7-octadien (OD) and hydrogen-terminated silicon. The OD-monolayer had H 2 C-terminated groups. The properties of OD-monolayer were evaluated by atomic force microscopy (AFM), ellipsometry and water contact angle measurements. The H 2 C-terminated groups were site-selectively oxidized through scanning probe anodization and ultraviolet (VUV) irradiation. The sample surfaces fabricated were evaluated by Kelvin force probe microscopy (KPFM) and X-ray photoelectron spectroscopy (XPS). Chemical conversion of functional group in the OD-monolayer was evaluated based on the surface potential change and the immobilization of fluorescence-labeled spheres onto the sample surfaces.

Ultra-water-repellent (UWR) films were prepared by microwave plasma-enhanced chemical vapour deposition using trimethylmethoxysilane and aluminium (III) diisopropoxide ethylacetoacetate (ADE) as raw materials. The film was mainly composed of silica and alumina and was apparently transparent. The film thickness was approximately 500 nm. The sample surface was treated with an organosilane in order to introduce hydrophobic groups. The hydrophobic modification led to a water contact angle of more than 150°, whose value corresponds to the UWR surface. The hardness of film with an optimized Al content was significantly improved compared with that without Al. The maximum hardness was 1.71 GPa. In consequence, we successfully prepared an UWR film in the silica–alumina system.

To explore the work function of a typical amorphous-CN film containing a nitrogen concentration of 23.5 at.%, surface potential images were acquired using Kelvin probe force microscopy. Based on the Fermi level of the n-type Si and the contact potential difference between the amorphous-CN film and the n-Si substrate, the work function of the amorphous-CN film was estimated to be 5.2 ± 0.2 eV below its vacuum level. Using the surface potential depth profile for an etched amorphous-CN film, energy diagrams of the amorphous-CN/SiO 2 /n-Si interface were constructed based on the positional relationship of the Fermi level. These band diagrams showed that band bending occurred at the amorphous-CN/SiO 2 /n-Si interface despite the Fermi level pinning effect of surface trapping due to the SiO 2 insulator layer.

Human plasma fibrinogen (HPF) was observed by atomic force microscopy (AFM) and Kelvin probe force microscopy (KPFM) conducted in non-contact mode. The HPF was adsorbed on a highly oriented pyrolytic graphite (HOPG) substrate as single molecules, as aggregated bundles, and as aggregated fibers. Topographic and phase images confirmed structural changes in the HPF after exposure to air, while topographic and KPFM images confirmed fibers with the width of a single HPF molecule. Additionally, KPFM confirmed the surface potential difference between the HPF and the HOPG, and periodical potential drop reflecting the E and D domains in the fiber.

Cathodic electrodeposition of ZnTe film was carried out on Au/Cu substrate using three kinds of citric acid electrolytes, each with a different counter anion, i.e., sulfate, chloride, or nitrate ions, to investigate the anion species’ influence on the morphology, composition and structure of the resulting electrodeposited ZnTe films. Both chloride and nitrate electrolytes gave crystalline ZnTe films with almost stoichiometric ZnTe composition under electrolytic conditions similar to those optimized previously for sulfate electrolyte. The mean crystallite size of the electrodeposited ZnTe films ranged from 13 to 37 nm. The effect of the ionic species on the crystallite size was also investigated. The degree of ZnTe(1 1 1) plane orientation of the films obtained from nitrate electrolyte was stronger than that of the films from sulfate or chloride electrolytes. High resolution SEM observations revealed different morphologies depending on the anion in the electrolytic solution.

ZnTe thin films were electrochemically deposited onto Au-coated Cu substrates from an electrolytic solution containing ZnSO4, TeO2, citric acid and sodium citrate. Effects of deposition potentials and solution's Zn concentrations on the structure, chemical composition and electrical property were investigated. The resistivity, conduction type, carrier density, and carrier mobility were evaluated with a Hall effect measurement apparatus. A film with nearly stoichiometric composition was deposited at -0.80 V vs. Ag /AgCl at 353 K from a solution containing 2.0×10-2 kmol m-3-ZnSO4, 1.0×10-4 kmol m-3-TeO2, 9.0×10-2 kmol m-3-citric acid and 2.1×10-1 kmol m-3-sodium citrate and was well crystallized with cubic preferential orientation along the (111) plane. A resistivity, the carrier density and the carrier mobility were 4.1×102 Ωm, 2.9×1019 m-3 and 5.3×10-4 m2 V-1 s-1, respectively.

Control of spatially localized chemical reactions such as site-selective reversible chemical conversion of functional groups and metal deposition on nano and/or micro areas is important to fabricate new devices in the next generation. In this study, the reaction controls were attempted with a nano probe. In the reversible chemical conversion, amino-terminated self-assembled monolayers (SAMs), which were prepared on Si substrates from (p-aminophenyl)trimethoxysilane (APhS) through chemical vapor deposition, were electrochemically converted into nitoroso-terminate ones using an atomic force microscope. The electrochemical reaction required the positive bias voltages of +0.5 to +3V. In order to define the chemical conversion, the sample substrates were immersed in a solution of pH=4 containing carboxylate-modified polystyrene (PS) spheres. The PS spheres were site-selectively adsorbed on the non-scanned regions. This indicates that non-scanned regions justifiably correspond to amino-terminated SAMs. On the other hand, the PS spheres were not adsorbed on the scanned regions at all, since the regions were oxidized and converted into nitoroso-terminated SAMs. Furthermore, the oxidized regions could also be reduced by a probe with negative bias voltage of −2V. The site-selective electroless deposition was actualized using a surface-induced reduction of gold ions combined with scanning probe lithography. Gold nano- or micro-structures on hydrogen-terminated Si surfaces were demonstrated. After fabrication of an Au nanostructure, 1-hexadecanethiol was immobilized on the Au surface. The result shows that we successfully controlled chemical reactions in nanometer-scale by the formation of metal patterns with the SPM.

Copper–indium–telluride films were electrochemically deposited from solutions containing CuCl 2 , InCl 3 , TeO 2 and HCl. Although a flat and smooth film with closely stoichiometric composition was deposited at −660 mV vs. Ag/AgCl at 303 K from a solution of 2.5×10 −4 mol dm −3 CuCl 2 , 1.0×10 −2 mol dm −3 InCl 3 , 5.0×10 −4 mol dm −3 TeO 2 and 0.1 mol dm −3 HCl, a polycrystalline CuInTe 2 film was not obtained. Increasing the temperature from 303 to 363 K allowed the deposition at lower overpotential of a polycrystalline CuInTe 2 film with closely stoichiometric composition and increased indium content. The band gap of the polycrystalline CuInTe 2 film electrodeposited at 363 K at −660 mV was 0.98 eV.

Bi2Te3 thin films were electrochemically deposited from ammonia-alkaline solution containing Bi(NO3)3, TeO2, nitrilotriacetic acid (NTA), in which Bi(III)- and Te(IV)-species were dissolving to form Bi(NTA)23- complex and TeO32-, respectively. This study revealed the relationship between [Bi]/[Te] ratio in the solution and the respective metal ratio in the deposited film. The [Bi]/[Te] ratio of the deposited film was successfully controlled by conducting electrodeposition under diffusion-limited conditions, i.e. the [Bi]/[Te] ratio in the solution was linearly related to that of the deposited film, where the partial current density originating from bismuth and tellurium ion was directly proportional to the concentration of respective ions. Dense and crystalline Bi2Te3 thin films with stoichiometric composition were electrodeposited at the potential ranging from −0.6 to −0.8 V from 5.0×10-3 kmol m-3 Bi(NO3)3 · 5H2O, 3.0×10-3 kmol m-3 TeO2 and 0.1 kmol m-3 NTA solution, with cathodic current efficiencies being above 85%.

Ge10Sb67.5Te22.5 thin films were prepared by RF magnetron sputtering from a single high purity Ge10Sb67.5Te22.5 target under the following condition: RF power: 30 W, Ar pressure: 1.067 Pa, Ar flow: 9 ccm, substrate temperature: room temperature (water cooling), distance between target and substrate: 7 cm, and sputtering time: 10∼40 min. Although the as-deposited film was amorphous, annealing for 30 min at 573 K allowed it to be crystallized. The crystallization temperature and the activation energy of Ge10Sb67.5Te22.5 thin film were around 463 K and 2.50 eV, respectively, while those of Ge2Sb2Te5 thin film, prepared under the same conditions as stated above, were around 408 K and 2.04 eV, respectively. The difference of optical constants between crystalline and amorphous phases of Ge10Sb67.5Te22.5 and Ge2Sb2Te5 thin films were −0.9+i 0.93 and −0.77+i 0.67, respectively, in a blue laser area, i.e., wavelength 405 nm.

Potentiostatic cathodic electrodeposition of ZnTe was investigated from the viewpoint of the effect of pH on the deposits' composition and crystallinity using citric acidic electrolytic baths, in which Zn(II) and Te(IV) species were dissolved to form ZnH 2 Cit + , ZnHCit, ZnCit - , Zn(Cit) 2 4- and HTeO 2 +, HTeO 3 -, respectively (Cit: citrate) at various pH. The complex equilibrium calculation was carried out to examine the most predominant complex ion for Zn-Cit system at different pH. Deposition of three kinds of deposits, i.e., polycrystalline ZnTe with closely stoichiometric composition, crystalline Te, and the mixed crystal due to Te and ZnTe, can be controlled by changing the pH and [Zn(II)]/ [Te(IV)] concentration ratio of the baths. All the deposits obtained at pH 4.0 were well crystallized with a ZnTe cubic preferential orientation along the (111) plane without any post-treatment. The difference of the electrodeposition behavior at various pH was also discussed.