Novel conveyer gels exhibiting autonomous peristaltic motion without external stimuli were prepared by copolymerizing temperature-responsive N-isopropylacrylamide (NIPAAm), ruthenium tris(2,2’-bipyridine) (Ru(bpy)₃) as the catalyst for the Belousov-Zhabotinsky (BZ) reaction and 2-acrylamido-2-methylpropanesulfonic acid (AMPS). The prepared bulky gel had an aggregative structure of its microgels when the AMPS feed ratio was low due to the effect of the poor solvent in the polymerization process. That structure highly improved the swelling-deswelling kinetics and generated swelling-deswelling amplitude more than 10% of the gel thickness, which was approximately 10 times larger than that of the gel with a homogeneous network structure. Further, we attempted to transport an object by utilizing the peristaltic motion of poly(NIPAAm-co-Ru(bpy)₃-co-AMPS) gel. A cylindrical poly(acrylamide) (PAAm) gel was transported as a model object on the poly(NIPAAm-co-Ru(bpy)₃-co-AMPS) gel surface wave when the gel had the aggregative structure of its microgels.

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Thermosensitive poly(N-isopropylacrylamide) gels with highly-ordered honeycome surface and inverse opal structure were successfully fabricated by several microfabrication methods using closely packed silica beads as a template. The gels are able to reversibly change the shapes and sizes of the pores with swelling-deswelling by temperature changes. In particular, regular buckling was induced due to compression with swelling. Such a thermoregulation of surface topography might be useful for design of functional surfaces with tunable physical properties.

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Lipid bilayers supported on solid substrates are considered to offer a potential as biological devices utilizing biological membranes and membrane proteins. In particular, highly patterned bilayers hold a promise for the development of biological devices. Previously, we proposed the concept of “active patterning” and demonstrated the gel-phase domain patterning in the supported bilayers of the DMPC-DOPC system using the light irradiation technique. The essence of this technique is the control of the spatial distribution of bilayer composition due to the local temperature increase. In this study, we applied this technique to the assembly of artificial raft domains in the supported lipid bilayers of the PSM-DOPC-cholesterol ternary system. After the light irradiation, the raft domain size increased in the irradiated region. This result means that the local PSM condensation enhanced the formation of the rafts, and it implies the possibility of the active patterning of the raft domain.

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Shape transformation of phospholipid vesicles on oxide surfaces was investigated by a fluorescence microscope. The transformation of spherical vesicles to a planar lipid bilayer membrane spontaneously proceeded on mica and glass, while the intact vesicular layer formed on TiO₂. Interaction energy between the substrate and the bilayer, which was evaluated using the rigorously calculated Hamaker constant, was ～10 times larger on TiO₂ than on mica and SiO₂. The results seems inconsistent with the conventionally proposed adhesion induced tension model, in which stronger adsorption leads to easier planar membrane formation from vesicles, thus indicate that the shape transformation from vesicles to a planar membrane is dominated by the kinetic processes and the dynamics of the vesicles, rather than the adsorption state of individual vesicle. Area-selective SPB formation of adsorbed vesicles was induced by the irradiation of strong excitation light, which was assisted by the photo-induced expansion of SPB containing dye-labeled lipid molecules.

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We developed new polymer nanoparticles containing quantum dots with artificial cell membrane-biointerface as a highly sensitive bioimaging probe. These nanoparticles were prepared by assembling phospholipid polymer as a platform and oligopeptide as a bioaffinity moiety on the surface of the nanoparticles. They showed high resistance to non-specific cellular uptake from HeLa cells due to the nature of phospholipid polymer with phosphorylcholine groups. On the other hand, when arginine octapeptide was immobilized on their surface, they could permeate the membrane of HeLa cells effectively and good fluorescence based on quantum dots could be observed. Cytotoxicity and inflammation reaction were not produced by these nanoparticles even after immobilization of octapeptide. Thus we obtained stable fluorescent polymer nanoparticles covered with artificial cell membrane, which are useful as an excellent bioimaging probe evaluation for biomolecular function in the target cells.

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  Novel silicone hydrogel materials with extremely hydrophilic surfaces were synthesized from two polymer components. Silicone networks prepared from bis(trimethylsilyloxy)methylsilyl propylglycerol methacrylate (SiMA) and hydrophilic networks prepared by the polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) in poly(SiMA) networks were used to construct an interpenetrating polymer network (IPN) structure. Random copolymerization of SiMA and MPC was also carried out to obtain control hydrogel samples. The obtained IPN hydrogel materials had highly hydrophilic surfaces in addition to good transparency, mechanical properties. Further, they showed good oxygen permeability because of the presence of the SiMA unit and good resistance to protein adsorption because of the presence of the MPC unit. Results of x-ray photoelectron spectroscopic analysis and microscopic FT-IR spectroscopy revealed that the superhydrophilicity of the IPN hydrogels was due to the surface concentration of the MPC units. The IPN hydrogel was confirmed to be suitable for the fabrication of soft contact lenses.

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Segmented polyurethanes (SPUs) are widely used in biomedical field such as cardiovascular catheters, diaphragms of artificial hearts because they have flexible but tough mechanical properties. However, their antithrombogenicity under blood contacting conditions are not sufficient to prevent clot formation for long term. For preparing small-diameter vascular grafts, it is necessary to obtain both antithrombogenic and biocompatible surface. In this study, poly(2-methacryloyloxyethyl phosphorylcholine-block-2-ethylhexyl methacrylate) (B-PMEH), which has an affinity with SPU on a molecular level was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization method. The B-PMEH was blended for preparing a SPU/B-PMEH polymer alloy membrane (SB film). This film drastically lowered the amount of absorbed fibrinogen and platelet adhesion compared to that on SPU without any adverse effect on the mechanical property of the SPU when B-PMEH was highly concentrated at the surface of the SB film. This means that the poly(MPC) segments in the B-PMEH improved the antithrombogenicity of the SPU. We succeeded in preparing a novel polymer alloy that possesses both the good mechanical property and the improved antithrombogenicity.

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Biointerface for highly sensitive immunoassay was constructed by molecular integration between a phospholipid polymer platform and an antibody as a bioaffinity ligand. The phospholipid polymer platform with nanometer-scaled particle deposition surface was constructed with poly[2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate (BMA)-co-p-nitrophenyloxycarbonyl poly(ethylene glycol) methacrylate (MEONP)] (PMBN) by an electrospray deposition (ESD) method. The PMBN surface, which can conjugate the antibodies, prevented the nonspecific protein adsorption. However, the nanometer-scaled structure of PMBN lost their shape after contact with an aqueous medium. To stabilize the nanometer-scaled structure in an aqueous medium, the PMBN was cross-linked with 1,4-butylenediamine and then heating was applied. Both cross-linking of PMBN and heating were very effective for improving the water stability of the nanometer-scaled structure, that is, remaining high porosity even after immersing in water. The specific signal in the enzyme-linked immunosorbent assay (ELISA) was enhanced after improvement of water stability of the PMBN platform. We concluded that the stabilization of the nanometer-scaled structure of the platform against water was effective to obtain highly sensitive immunoassay.

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A novel procedure for immobilizing orientation-controlled antibodies was investigated using tyrosinase catalyzed immobilization of Staphylococcal protein A (SpA). We synthesized well-defined structured block-type polymer, poly(2-methacryloyloxyethyl phosphorylcholine(MPC)-block-2-aminoethyl methacrylate (AEMA)) (PMbA) from the substrate by surface-initiated living radical polymerization for bioconjugation. One of the segments in the PMbA, poly(MPC) provides hydrophilicity and biocompatibility and the other segment, poly(AEMA) possesses amino groups for conjugation with biomolecules. On this PMbA polymer grafted substrates, SpA is first oxidized by tyrosinase and then immobilized to the amino group of the substrate through the active quinone groups in the SpA. The PMbA substrates showed a good resistance for non-specific protein adsorption, due to its primal layer of poly(MPC) segments. As the result of sandwich immunoassay, this system using tyrosinase and SpA showed the best primary antibody/secondary antibody ratio among the system without SpA and that with randomly oriented SpA. This procedure can be further utilized for achieving higher sensitivity of immunoassay systems.

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To develop hybrid artificial organs, we prepared a heterogeneous functioned polymer membrane as an interface between blood and tissue. The membrane was constructed by three polymer layers, that is, cellulose acetate membrane as a base membrane, photo-reactive gelatin and a phospholipids polymer (poly[2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate (BMA)](PMB)). Gelatin and PMB layers were introduced on each side of the cellulose acetate membrane. The gelatin layer played as cell adhesive, but PMB layer prevented cell adhesion. We observed good cell proliferation on the gelatin side and blood compatibility on PMB layer. The heterogeneous functioned polymer membrane possessed permeability of insulin. The heterogeneity of this membrane represented the two conflicting surface properties in one: cytocompatible surface on one side and an antithrombogenic surface on the other side. We considered that the membrane has the solute permeability to transport the products of cells. It could be concluded that the membrane is excellent hybrid of polymer and cells for realizing hybrid artificial organs.

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  Multi-array analysis method recently attracts attention as a useful technique to detect antigen-antibody interactions in a small amount of reagents. Surface plasmon resonance (SPR) has been used as one of the highly sensitive techniques which can detect antigen-antibody interaction in the multi-array coated by a thin metal film. We proposed the surface plasmon field-enhanced fluorescence Imaging (SPFI) with higher sensitivity than SPR detection. The fluorescence from fluorescence molecules near the substrate (within 40 nm) is quenched by a thin metal film as found from previous studies. Therefore the change of distance due to the interaction of the protein (antigen) in cell with antibody immobilized at the substrate surface was monitored by the change of the fluorescence intensity using SPFI. Further we fabricated array spots on the substrate using a self assembled monolayer (SAM) possible to suppress the non-specific adsorption out of the spot exposed to UV light, and the antibody was prepared into the spots. Two kinds of antibodies modified with fluorescent-dyes were immobilized to the different array spots. Our SPFS system can recognize binding of cells based on the specific antigen-antibody interaction in the multi-array system.

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  Supported lipid bilayers (SLB) are expected to offer a potential as biological devices utilizing biological membranes and membrane proteins. In this work, we investigated the effect of an external DC field on the phase-separated structures of gel phase and liquid crystalline phase in the SLBs of the DMPS-DOPC binary systems. The electric field was vertically applied to the SLB using a three-electrode system. The voltage apply of −1.0 V at the backside of the SLB increased the gel-phase domain size, while the voltage apply of +1.0 V decreased the domain size. This electric field effect is strongly related with the existence of PS lipids that is a negatively-charged lipid. Previously it was reported that the size of brain-PS-rich domain depends on the Ca²⁺ concentration. This implies that it is possible to change the domain size due to the change of the Ca²⁺ concentration near the surface of the SLB by applying the electric field.

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A pH-stat continuous-bubble-column scrubber using CO₂-Zn(NO₃)₂-NaOH as a reacting system was used to prepare the precursors of ZnO. The experiments were carried out in the pH range of 10-13 and in the gas-flow rate range of 3-8 L/min. The process favored the formation of zinc carbonate hydroxide hydrate at lower pH values and/or higher gas-flow rates, while the major precursor was hydroxide hydrate at higher pH values. To quantitatively determine the composition of precursors, the powders were examined by XRD analysis. Also, the decomposition temperatures of precursors were observed from thermal analysis. Examinations of photoluminescence (PL), XRD, and BET for nano-zinc oxide particles obtained in here are required and the results are compared with that standard zinc oxide powders.

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The authors reported elsewhere ITO transparent conducting films prepared by spraying ethanol solution of indium (III) chloride and tin (II) chloride using an inexpensive perfume atomizer onto a glass substrate at 350℃; Y. Sawada et al., Thin Solid Films 409, 46 (2002) and Y. Sawada, Mater. Sci. Forum 437/438, 23 (2003). In the present study, tin-doping was attempted under identical experimental conditions except for using tetravalent tin (IV) chloride which can be dissolved in ethanol more easily than divalent tin (II) chloride. The minimum resistivities (1.4×10^-4 and 7.0×10^-5 ohm cm), respectively, for the as-deposited and after annealing at 600℃ in reducing atmosphere were approximately equal to our previous one (1.7×10^-4 and 7.9×10^-5 ohm cm). The lowest resistivity after the annealing was compatible with that (7.7×10^-5 ohm cm) of the single-crystal ITO film deposited by pulsed-laser-deposition process onto an yttrium-stabilized zirconium oxide single crystal (Ohta et al., Appl. Phys. Lett. 76 (19) 2740 (2000)). Carrier concentration and mobility, optical transmittance and reflectance were also similar to those deposited using tin (II) chloride reported previously. These results suggested the formation of tin (II) chloride during the deposition process using tin (IV) chloride.

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The X-ray refraction imaging technique, diffraction-enhanced X-ray imaging (DEI) method with an asymmetric reflection analyzer was applied to determine the distribution profile of hydride in titanium. Horizontal magnification of the image by the asymmetric reflection was 9 times. Hydride was formed on titanium surface by electrolytic-charging at room temperature for 10, 25.5, 48 and 150 h. The specimen was cut into a 1-mm thick slice for cross-sectional observation. Hydride layer was observed by DEI method as a thick black or white line parallel to the surface. X-ray intensity profile of hydride was measured from the DEI image and converted to the deviation angle of X-ray by refraction using the observed rocking curve. The distribution of refraction index was calculated from the deviation angle of X-ray using Snell’s low. Finally distribution of ratio of hydride and titanium, the concentration profile of hydride, was obtained from that of the refraction index. The distribution profile of hydride in titanium was determined to accuracy of the order of micrometer by means of the DEI method with asymmetric reflection analyzer.

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  In the Ba₂(M,M')₂O₅ (M=Al, Ga, Sc, Zn; M'=Lu, Yb, Tm, Er, Y, Ce, Zr, Hf, Nb, Ta, W, Mo) systems, some new brownmillerite-type compounds were successfully synthesized when M=Sc, M'=Lu, Yb, Tm and Er. It was found that the larger ion of the B-site ion pairs strongly influences the lattice size of the new compounds and that the compounds having the larger unit cell free volume can uptake the large amount of H₂O. In the case of M=Zn, M'=Ce, Zr, Hf, Nb and Ta, the cubic perovskite-type phases were successfully synthesized. The electrical conductivity of the new phases was discussed according to the unit cell free volume of the perovskite-type structure.

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The dielectric properties of Ca-stabilized ZrO₂ (Zr_0.9Ca_0.1O_2-δ, 10CSZ) which is an oxide ion conductor were investigated. Numerical analyses for the frequency dependence of dielectric constant (ε_r′) and dielectric loss factors (ε_r″) revealed that the dielectric properties were made up of Debye-type polarization due to dopant-vacancy associates [Ca_zr″-V_o¨] and interfacial polarization at electrolyte-electrode. Two Debye-type relaxations were observed. This result implies the existence of two dopant-vacancy associates with different distances. Moreover, by using the dielectric constants obtained from the numerical analysis, the frequency dependences of ac conductivity (σ_ac) and dielectric loss tangent (tanδ) were also explained.

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  In the present work, the morphological development of acicular ferrite in situ, was observed during weld cooling. The nucleation and growing at inclusion, sympathetic nucleation and impingement event of acicular ferrite were directly shown in high time resolution. To clarify the evolution mechanism, the inclusions related to acicular ferrite formation were investigated from the crystallographic points of view. The foiled samples including inclusions were prepared with a focused ion beam (FIB) device and were observed with a transmission electron microscope (TEM) which was operated at an acceleration voltage of 200kV. Inclusions were surrounded by a narrow titanium oxide. It was identified as TiO. The Baker-Nutting orientation relationship was satisfied between the TiO and acicular ferrite. It was supposed that the TiO on the inclusion surface contributes to the heterogeneous nucleation of acicular ferrite, supplying low interface energy.

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  Tetragonal layered perovskite-type oxide systems Ca_2.73-mNd_mMn₂O_7-δ (0 ≦ m ≦ 0.18) and orthorhombic perovskite-type oxide systems having A-site vacancy, Ca_1-n□_nMnO₃ and Ca_0.9-nNd_0.1□_nMnO₃, were synthesized by a standard ceramic technique. The thermoelectric properties such as Seebeck coefficient (S), thermal conductivity (κ) and electrical conductivity (σ) were investigated as functions of temperature and composition. The effect of insertion of rock salt layer or A-site vacancy to the perovskite-type structure on the thermoelectric properties, were clarified.

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The Eco-MCPS database is a web-based database system that includes environment-friendly materials, components, products, and services. The text data stored in the Eco-MCPS was analyzed by text-mining showed that eco-product environmental performances are realized by the use of environment-friendly components or materials. The access log of Eco-MCPS was subjected to data mining, and the association analysis suggested that there are item relations formed by the user interest. Based in these results, it is suggested that the enhancement of collaboration between manufacturers and material or component suppliers improves the development of environment-friendly products and provides the “suggesting function”, thereby promoting this collaboration.

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Indium oxide and tin-doped indium oxide (ITO) films were fabricated by repeating dip coating and heating at various temperatures in air for 30 minutes before annealed in N₂-0.1%H₂ at 600℃ for 30 minutes. The heating at 300℃ resulted in porous nanostructure composed of small grains and crystallite size. Densification and growth of grain and crystallite size were remarkable when heated at 800℃. Resistivity of the film decreased by increasing the heating temperature until at 500-700℃. The resistivity increase at the higher heating temperature was attributed to the crack formation of the films. The lowest resistivity (5.5×10^-3 ohm cm) was obtained when the ITO film was prepared at 500℃.

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Electrical discharges in water have been studied for more than thirty years and during that time, significant progress has been made on the understanding and characterization of basic processes taking place in the water. The main molecular species formed by pulsed discharge in water are hydrogen, hydrogen peroxide and oxygen, although oxidative (hydroxyl radical) and reductive radicals (superoxide radical anion) that are produced by the discharge are responsible for the degradation of molecules. Streamer electrical discharge in water has been studied by numerous investigators and overall reactor design and pollutant degradation efficiency has been optimized.
Our research group opened a new direction in plasma applications by conducting electrical discharges in relatively polar organic liquids. In that manner, we were able to produce Diamond-Like Carbon (DLC) film on the tip of a high voltage electrode by the electrical discharges in acetonitrile and dimethyl sulfoxide. We also studied electrical discharges in ionic liquids and above the ionic liquid surface, a new generation of solvents that are gaining more interest in both fundamental and applied research. The results indicated that the discharge inside the ionic liquid is destructive and leads to polymerization, whereas the discharge above the liquid surface is less destructive and could find possible applications.

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A ns pulse voltage was used to drive a coaxial geometry corona reactor to synthesis ozone with high energy yield. The ns pulse voltage was produced using an inductive energy storage system pulsed power generator using semiconductor opening switch (SOS) diodes. First recovery diodes were used as SOS diodes in the inductive energy storage system pulsed power generator to produce short-pulse high voltage with high-repetition rate. The pulse voltage of 12 ns width and 17 kV peak voltage was produced at charging voltage of -5 kV and was applied to a 1 mm diameter center wire electrode in the coaxial geometry reactor. The copper cylinder of 19 mm inner diameter was used as outer electrode and was connected to a ground. The ozone yield of 230 g/kWh was obtained using ns narrow pulse voltage. This value is almost 20% higher than 190 g/kWh obtained by 60 ns width pulse.

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  We measured the heat flux applied to a Litiumniobate (LiNbO₃) substrate using a LiNbO₃ laser interferometer in atmospheric pressure plasma (APPJ). Compared to the consumed energy of the plasma reactor, determined by the V–Q Lissajous figure, the energy input from the APPJ to the LiNbO₃ was approximately 20%.

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A capacitor discharge joining technique was investigated to optimize circuit parameter for improvement of bonding strength to fabricate an alumina (Al₂O₃) tile-titanium foil-Al₂O₃ tile joint. Several kAmps pulse current was supplied from a storage capacitor to the titanium foil while simultaneously applying pressure to the joint. The Al₂O₃ tiles were successfully bonded when the input energy reached approximately the same value with the energy required for vaporization of the titanium foils and the shear strength increased with increasing consumed energy into the foil. However, the Al₂O₃ tiles were fractured without bonding when the consumed energy was much higher than that required for vaporization of the foil. The shear strength slightly decreased with increasing capacitance of the energy storage capacitor at same consumed energy. However, the tiles were joined without fracturing at consumed energy much higher than that for foil vaporization. The shear strength of the tiles increased from 350 to 600 kgf with increasing compressing pressure of the tile from 0.4 to 8 MPa.

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  In this study, we developed a new solution method, Peroxide Sol-Gel (PSG) method to obtain the LiTaO₃ photocatalytic powder. This method uses the peroxo tantalum complex as a starting material. The precursor powders prepared by PSG method by spray-drying, formed spherical and hollow shaped particles and crystallized above 500 ℃. When the precursor was annealed at 700℃, the sample with the highest photocatalytic activity (H₂: 539 μmol/h and O₂: 253 μmol/h) was produced. The activity of this sample exceeded the activity of solid state reaction (SSR) method's sample. By use of the PSG method together with spray drying, the high-performance photocatalytic powders of LiTaO₃ having large specific surface areas and small primary particle sizes have been obtained.

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Water-soluble titanium complexes were synthesized starting from TiCl₄ as a source of Ti. TiO₂ was prepared by hydrothermal treatment of the obtained Ti-malate complex. The TiO₂ sample was characterized by X-ray diffraction (XRD), X-ray fluorescence analysis (XRF), Transmission electron microscopy (TEM), UV-Visible spectroscopy. The sample consisted of ～10 nm mono-dispersed anatase particles. A blue shift of absorption due to quantum size effect in the nanoscale anatase particles was observed. Transparent stable colloid suspension was obtained by dispersing the prepared nano-sized anatase into water. For the photocatalytic patterning, Ti-glycolate complex was added into the colloid solution and this resulted solution was coated on a glass substrate. After drying, the film was covered by a photomask and irradiated by UV light. The irradiated part became insoluble due to the photocatalytic reaction promoted by anatase particles. The film of masked part was removed by washing with water, and patterned film was fabricated.

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The effect of a tripeptide molecule glutathione (γ-L-glutamyl-L-cysteniylglycine, QCG) is studied as a structure-directing agents (SDA) for cathodic electrodeposition of ZnO and CuSCN from aqueous solutions, which are known to be wide bandgap semiconductors of n and p types, respectively. From experiences, hard Lewis basic –COOH group act as an anchor to the hard Lewis acidic Zn(II) sites of ZnO, whereas soft Lewis basic groups such as –SH and –NH₂ are expected to interact with soft Lewis acidic Cu(I) sites of CuSCN. QCG have all these anchoring groups within its structure and was found to affect the growth of both ZnO and CuSCN, leading to alteration of crystallographic orientations and evolution of unique nanostructures.

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Growing from supercooled melt crystal shows complicated shapes like trees which have periodical side branching. This solidification pattern called dendrite is one of self-organized phenomena. In this phenomenon, phase and temperature distributions interact with each other during the crystal growth, since the phase transition causes latent heat. Thus, the side branches are induced from instabilities at the side wall of dendrite, though the tip of the dendrite shape was stable. In this study we have simulated pure-metal solidification by adding periodic thermal perturbations at the vicinity of the dendrite tip to investigate the shape of side branching. As a result, two types of side branches were observed when local perturbations had appropriate frequency. One type shows small wave length induced directly from perturbations, and the other large wave length expressed in comparatively away from tip. Former thin branches were attenuated to be disappeared during the latter main arms were advanced in propagation. Especially when the perturbations had small periodicity, thin side branch had not been attenuated in certain distance from modulating point. Additionally we evaluated distance from modulating point to attenuation starting point which was expected that modulation had operated side branching directly.

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A model of leakage current in Al/HfO₂/SiO₂/Si MOS (metal-oxide-semiconductor) capacitors is given by adopting the tunnel current model in SiGe-based heterojunction bipolar transistors. The velocity of an electron in the metal gate, which originates from the coupling between longitudinal and transverse (in-plane) kinetic energies, and the anisotropic mass of the substrate were included in the leakage current model. It was found that the leakage current obtained by including the gate electron velocity is lower than that calculated without the coupling effect and the leakage current decreases with an increasing gate electron velocity. However, the leakage current is not significantly influenced by the silicon substrate orientation. If a measured leakage current in the high-K dielectric stack MOS with Si(100) substrate were much higher than that in the MOS with Si(111) as observed in the conventional MOS, then the gate electron phase velocity in the latter would be higher. A small increase of the equivalent oxide thickness (EOT) of HfO₂ will decrease the tunnel current appreciably and tunnel current oscillations become visible as the EOT becomes thicker. Oscillatory behavior of the tunnel current is due to resonance states in the quantum well formed in high-K dielectric stack at high electric fields.

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The annealing behavior of an La₂O₃ thin film deposited on an Si (001) substrate was studied by spherical aberration corrected transmission electron microscopy. The thickness and roughness of the as-deposited and 300/500℃ post-deposition annealing (PDA) films was measured precisely. Composition analysis of the films was performed by electron energy loss spectroscopy. Based on the results, we propose a model for atomic diffusions and reactions during the PDA. We clarify the reason that the 300℃ PDA brings better electric properties than the as-deposition and the 500℃ PDA.

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We investigated the dependence of strain relaxation and Sn precipitation on the thickness and the growth temperature of the Ge_1-xSn_x layer on a virtual Ge substrate. We found that the strain relaxation of the Ge_1-xSn_x layers is enhanced by increasing the thickness of the Ge_1-xSn_x layers. Additionally, the much higher degree of strain relaxation of 87% and higher Sn content of 6.8% were realized by lowering the growth temperature of the Ge_1-xSn_x layers. The low temperature growth probably enhances the introduction of point defects contributing to the creation of new misfit dislocations at the Ge_1-xSn_x/Ge interface. The Ge_1-xSn_x layer grown in this study has the potential to induce a tensile strain of 0.86% to the Ge layer.

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  We have investigated the anisotropic strain structure of micro-patterned Ge/Si_1-xGe_x mesa lines. The elastic strain-relaxation of a Si_1-xGe_x layer by micro-patterning induces an uniaxial tensile strain into a Ge layer only for the direction perpendicular to the line. The pattern size dependence on the behavior of the elastic strain-relaxation of Si_1-xGe_x layers is analyzed by FEM. Additionally, the XRD results for micro-patterned samples suggest that the overetching depth of the Si substrate also influenced the strain-relaxation of the Si_1-xGe_x layers and the tensile-strain value of the Ge layers.

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We formed high density platinum-silicide nanodots on an ultrathin SiO₂ layer and characterized their electronic charged states by an AFM/Kelvin probe technique. A ～1.8-nm-thick Pt film deposited on pre-grown Si quantum dots (Si-QDs) with an areal dot density of ～1.2 × 10¹¹ cm^–2 was exposed to remote hydrogen plasma. The formation of platinum-silicide nanodots with an areal dot density of ～1.2 × 10¹¹ cm^–2 was confirmed after examining the surface morphology and measuring the valence band spectra by AFM and XPS, respectively. The surface potential of the nanodots changed in a stepwise manner with respect to the tip bias due to multistep electron injection into and extraction from the platinum-silicide nanodots.

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  A solution with nanocrystalline diamond (NCD) particles formed using the chemical vapor deposition (CVD) technique and post-treatment process was proposed. After the diamond deposition, the Si substrate with the deposited diamond particles was immersed in the HF/HNO₃ mixture acid solution to etch the Si substrate. The diamond particles dispersed in the etchant were collected using a membrane filter and re-dispersed onto the ethyl alcohol. Form observations of the diamond particles and grain size distribution before and after the wet etching process were carried out by scanning electron microscope (SEM) and dynamic light scattering (DLS). A mean diamond particle diameter of approximately 250 nm was observed in the samples. In order to compare the crystalline qualities of the grown diamond, the diamond before and after the wet etching process were analyzed by Raman spectroscopy and electron energy loss spectroscopy (EELS). The Raman spectra with the sharp peak in 1333 cm^-1 and the EELS spectra with the peak in 22.9 eV and 34.7 eV, oriented by the diamond particles, were confirmed. The results of these analysis indicated that there were no damage to the diamond particles by the wet etching process using the mixture acid etchant.

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Zinc Oxide (ZnO) nanostructures were deposited on SiO₂ using the sol-gel method. The effects of SiO₂ thickness on the nucleation and growth of ZnO nanostructures were studied. The oxidation time was varied from 5 minutes to 20 minutes to vary the SiO₂ thickness. We observed different surface morphologies of ZnO nanostructures when deposited without SiO₂ and with different thickness of SiO₂ using scanning electron microscope (SEM). The structural property of nanostructured ZnO was investigated using an x-ray diffractometer (XRD), and showed different crystal growth orientations. We also measured the electrical current-voltage (IV) response and found that it is strongly dependent on the size of ZnO nanostructures. The optical property was measured using a photoluminescence (PL) spectrometer which indicates that the peak intensity is inversely proportional to the ZnO crystallite size. In this experiment, we found that SiO₂ which oxidized for 5 minutes has the optimum optical property and is suitable for optical device applications.

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Damage to an aluminum (III) bis(2-methyl-8-quninolinato)-4-phenylphenolate (BAlq) layer was investigated during indium-tin oxide (ITO) deposition using a facing target sputtering (FTS) system in which the bombardment of negative oxygen ions and γ-electrons onto the substrate can be completely suppressed. The photoluminescence (PL) intensity of BAlq was used to evaluate the damage on the organic layer after the deposition of an ITO thin film in Ar and Kr gas at different gas pressures and input power levels. The results suggest that the bombardment of reflected neutral atoms is not the main reason for the damage. The remnant damage from the bombardment of sputtered atoms can be reduced by sputtering at a higher gas pressure. Finally, the bombardment of the organic film by high-energy particles such as negative oxygen ions, γ-electrons, and sputter-emitted atoms was completely suppressed using an FTS system to attain low-damage and high-rate sputter ITO deposition.

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Ion-current difference measurement by light intensity modulation ( ICD ) is introduced as a convenient method to characterize a purified beam of momentum-controlled neutral free radicals produced by photo-deionization of a negative ion beam for the purpose of surface-reaction-selective device processing. The ICD setup developed in this study to estimate the number flux of the photo-deionized neutral particles exhibited the high precision, sensitivity, and spatial resolution.

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Efficiency is currently becomes the main problem in μ-EDM processes. To have high efficiency in μ-EDM processes means that the workpiece machined is not only having good surface quality but also need to have high material removal rate during the machining process. In order to increase the efficiency in μ-EDM processes, micro MoS₂ powder mixed dielectric fluid is proposed as one of the solution. This study investigated the effect of micro MoS₂ powder mixed dielectric fluid with focusing on obtaining good surface quality and higher material removal rate. It was observed that by suspending micro MoS₂ powder can produce better surface quality by removing black spot in the center of surface machined. The better in surface quality also followed by increasing in material removal rate up to 70 % in certain of combination of tool electrode and workpiece material.

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Like other conventional smart materials, structural color showing smart materials inherit physical and chemical characteristics imposed by the templates. Smart Material such as structural colored gel made of photonic crystal (PC) as template, exhibits angle dependent structural color because the color arises from the Bragg optical diffraction of light from crystal planes. But angle independent or low angle dependent structural color is required for devising of display with a wide viewing angle. To meet this purpose we prepared photonic glass (PG) from silica colloidal spheres. This PG is able to exhibit structural color, which is stable against the change of the angle of view and the angle of illumination. The transmittance spectrum evidences the angle independence of the structural color of PG. The Fast Fourier Transformation and the autocorrelation function prove that we prepared an amorphous material. The existence of short range order helps PG to exhibit angle independent structural color.

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Temperature range of cholesteric blue phase (BP) was expanded by infiltrating liquid crystal (LC) that exhibits blue phases into the three dimensional structures such as polymer network (PN) and mixed cellulose ester membrane (MCEM). Reflection spectrum and dielectric properties of the expanded BP have been measured. Cooling rate dependence of the BP temperature range was also investigated, which indicated that the expansion of the BP temperature range upon infiltrating LC into the three dimensional structures was induced by the pinning effect. The expansion of the BP temperature range was induced by pinning effect on the network surfaces of these three-dimensional structures. In particular, the temperature range of BP I in the LC/PN composite has cooling rate dependence and is six times wider than that of pure BP LC compound at 0.1-℃/min cooling rate. Temperature range of BP in MCEM coated with other polymer was wider than that of in MCEM without polymer. The interaction between the surface of structure and LC molecules was affect the pinning power.

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The effect of atmospheric water vapor on the kinetic rate behavior of the thermal decomposition of zinc carbonate hydroxide, Zn₅(CO₃)₂(OH)₆, was investigated by means of TG-DTA under the controlled partial pressure of atmospheric water vapor, p(H₂O). With increasing p(H₂O) from 0.7 to 9.4 kPa, the reaction temperature at the restricted heating rate was reduced systematically accompanied by the change in the shape of TG curves. Through systematic kinetic analysis of the reaction at different p(H₂O), the change in the kinetic behavior was characterized by the mutually dependent decreases in the apparent activation energy and the Arrhenius pre-exponential factor, where the catalytic action of atmospheric water vapor on the surface nucleation process was identified as the possible mechanistic origin.

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  A series of polycrystalline La_0.7Sr_0.3MnO₃ (LSMO) films was deposited by sputtering on Ba_0.4Sr_0.6TiO₃ (BSTO)/YSZ (Yttria stabilized Zirconia) buffered Si substrates. Through changing the deposition temperature and thickness of the buffer layers, the LSMO films with grain sizes from about 10 nm to 100 nm were prepared. The results of transport properties of these polycrystalline LSMO films show that the MR value (which is the value after deducting the CMR part) strongly depends on the film resistivities. We also developed a dual path model which includes both the spin dependent tunneling and scattering to explain the low-field MR effect of LSMO polycrystalline films. And the experimental results can fit well with our dual path model.

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The spiro-type polymer having alternate structure of cyclic silphenylenesiloxane and cyclic carbosilane moieties was synthesized by the hydrosilylation polymerization of cyclic silphenylenesiloxane derivative having two allylhydrosilyl groups. The thermal properties of the obtained polymers were investigated by using the thermogravimetric analysis and the differential scanning calorimetry. The obtained spiro-type polymer, P3, exhibited the relatively high glass transition temperature of 77℃ and the weight residue at 1000℃ of 73 %. In addition, P3 annealed at 200℃ was an excellent heat-resistant material insoluble to common solvents. The dielectric constants, ε, of polymer films of P3 and the annealed sample were evaluated by the measurement of refractive indices estimated from the ellipsometry method. Both samples showed relatively low ε.

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  Lithium-manganese oxides have been studied as a cathode material in the Li secondary batteries. Preparation of LiMn₂O₄ thin films was tried with a RF magnetron sputtering method at the substrate temperature (T_sub) of R.T.. This material is superior to other materials in the cost performance as well as non-toxicity. The dependence of crystal properties on the Ar flow rate was examined. In the case of 60 min deposition time, the deposition rate was not varied as varying Ar flow rate from 2 to 3.5 sccm.

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Cyanobacterial polysaccharides, sacrans, are anionic megamolecules having extremely high molecular weights (Mw: 1.6 x 10⁷). We confirmed by FT-MS analyses that sacran is composed of various partial structures such as continuous and combination structures of uronic acids and hexoses. We used highly swollen sacran gels (swelling degree: 700-800 times of dry weight) prepared by chemical cross-linking with diamines such as l-lysine. Sacran gels shrank and clouded in aqueous solutions of In and Gd ions and showed more than 100 times adsorption ratios of these metal ions compared with non cross-linked sacran presumably due to continuous uronic acids.

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Several 2:1-type clay minerals with unique morphology has been synthesized under different hydrothermal conditions by a new concept called Geonics, which is “adaptation of processes in the formation of natural geologic analogues”. Illite particles exhibiting unique triangle-shaped particles up to a few hundred nm were obtained from an aluminous composition treated at 500℃ and 100 MPa for a day. A Long lath with a width of a few hundred nm and several ten micrometers long obtained at 450℃ and 100 MPa for 40 days are regular mixed-layer structure wherein smectite and mica nanosheets alternate periodically. The hexagonal and rhombohedral illite was observed on the product synthesized at 500 ℃ and 100 MPa for 40 days. The observations confirm that the assembly of silicate nanosheets and morphology should be controlled by chemical species, synthesis temperature, and duration.

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An efficient adsorbent made of hydroxyl aluminum-silicate has been developed for a desiccant air conditioning system and a carbon dioxide capture system. The XRD pattern shows that this adsorbent is amorphous, and the ²⁹Si and ²⁷Al NMR spectra show that the chemical species of Al and Si in some part of this adsorbent is similar to allophane and/or imogolite and those in the other part is similar to layered clay minerals. The amount of water-vapor adsorbed on this adsorbent is 36 wt% when the relative water-vapor pressure is at 0.6. This value is 1.4 times larger than the amount of water-vapor adsorbing on zeolite A, which is now used for the desiccant air conditioning system. Our newly developed hydroxyl aluminum-silicate is better than zeolite A for the adsorbent used in the desiccant air conditioning system because it adsorbs water-vapor in a wide humidity range and can desorb at the temperature as low as 80℃. The amorphous aluminum-silicate also adsorbs much carbon dioxide. The amount of adsorbed carbon dioxide on this material is 11.1 wt% when the pressure of carbon dioxide is raised from 100kPa to 900kPa. This value is 2.1 times larger than the amount of carbon dioxide adsorbing on zeolite X, which is now used for a carbon dioxide capture system. If the pressure swing adsorption (PSA) system can be operated more than the atmospheric pressure by using this material, the newly developed materials can collect carbon dioxide with low cost compared with the present system.

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