This paper describes new methods for the preparation of organic-inorganic polymer nano-hybrids. The materials obtained are expected to show many possibilities as new composite materials. Such new preparative methods should be one of the most important key technologies for the creation of high-performance or high-functional polymeric materials.

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Nanostructured materials have been an important subject since the late 1980s. There are many methods developed for synthesis of nanomaterials such as ball-milling, precipitation, hydrothermal method, chemical vapor deposition and so on. Different from these conventional methods, we have been studying synthesis of metallic, semiconductive and ceramic nanomaterials by hot and cold plasma methods and will present some results in this report.

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Ceramic coatings of multi-functional nanocomposite for the structural application are introduced in this presentation. Design and syntheses of those coatings based on not only superhardness but also low friction coefficient were conducted for the multi-component materials system. For example, various ternary, quaternary and quinary nano-structured coatings in the (Ti, Cr, Mo, Al, Si)-(B, C, N) system are compared in sense of superhardness as well as properties of corrosion, oxidation, friction etc. MeN/soft Me (Me = metal) system, e.g., MoN/Cu film were examined for low friction application. Co-deposition nitride/carbide of transition metals together with the SiNx, SiC, BN, or soft metals resulted in formation of nanocomposite coatings and led to superhardness, high thermal stability, and low-friction coefficients, etc. Also, several plasma-assisted vapor processes, such as plasma-assisted chemical vapor deposition, hybrid coating system of arc ion plating and magnetron sputtering, high power impulse magnetron sputtering (HIPIMS) were utilized to synthesize new materials having multifunctional properties by modifying their chemical compositions and microstructure. New HIPIMS+ techniques possess combining merits of magnetron sputtering and arc plasma show great potentials on depositing multi-functional hard coatings. Mn+1AXn (abbreviated as MAX, where M is an early transition metal, A is an IIIA- or IVA- group element, and X is C or N) phases are a family of nanolaminated compounds. The MAX-phase coatings exhibited high oxidation resistance. We are investigating the potential of MAX-phase on Ti and Ti-Al alloys as protective coatings.

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Biominerals such as nacre of shell, teeth, and bones are organic/inorganic hybrids, which have significant optical and mechanical properties due to their highly controlled hierarchical and complex structures. These structures are formed in mild conditions and their formation processes are controlled by macromolecular templates of peptides and polysaccharides. Herein we report our recent studies on the development of inorganic/organic fusion hybrids through molecular-controlled processes inspired by biomineralization. The novel composite materials with regular patterned surfaces and macroscopic orientation were prepared on functional synthetic polymer templates.

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This talk will introduce a novel solution method, polymer assisted deposition process, for the preparation of VO2 and VO2-based composite films. The method enables us to facially control over the film thickness, morphology and optical constants. By combining the optical design in the materials selection and/or their thickness and microstructural control, we obtained VO2 films with high visible transmittance (40-84%), controllable Mott phase transition temperatures and high switching efficiencies (max. 15.1%). The results show that the current solution process is a powerful competitor towards practical applications of this material. For further information, please read references.

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Various kinds of oxynitrides have been applied to luminescent materials and inorganic pigments because they have responces in visible light wave length region due to the more covalency of nitride anion than oxide. The arrangement way of oxide and nitride anions are introducing new interesting properties on oxynitrides. The relation will be expained between the arrangement and the functionalities such as large dielectric property and new superconductivity.

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We prepared luminescent silica by sintering porous silica doped with Mn or Cu which works as emission center. By co-dopant Al or Ga to Cu, the blue-green emission was greatly enhanced. In the case of Mn, co-doping of Zn was found to enhance the green emission due to the formation of microcrystalline of Zn2SiO4:Mn in silica. We found that fine control of sintering atmosphere is also a key to achieve a high efficiency. The internal efficiency of these silica was 0.28, 0.58 for Cu-Al doped and Mn-Zn doped silica, respectively.

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Metalic Al can be expected to act as a reducing agent in the silicate glass or germinate glass.In this study, mixing metallic Al into the starting material for SiO2-GeO2—CaO glasses are proposed as a means of forming oxygen defects in glass. Synthesized glass shows visible luminescence under ultraviolet excitation. Dominant luminescence wavelength is tunable from 420 to 740 nm by changing excitation wavelength .Luminescence attributes to three types oxygen defect structures( Si(_II_), Ge(_II_), Germyl radical) caused by reduction ability of metallic Al.

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Since the application of phosphors to cathode ray tube (CRT) display by Dr. Kenjirou Takayanagi at 1926, who displayed a Japanese word of "i" on CRT for the first time, phosphorous materials have been used in color Television (TV), Electro luminescence (EL) displays, Field emission displays (FEDs), Plasma panel displays (PDPs) and furthermore white light emitting diodes (w-LEDs) in the last 85 years. In this lecture, a fundamental of phosphors and recent development of phosphors together with their expanding applications including w-LED are introduced.

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Rare earths are used in various functional materials such as phosphors. Recent sudden rise in demand is causing a problem in steady supply. Development of materials based on a concept of rare-earth-free is quite important and, in this work, we focus on the capability of vanadate ions as a luminescent center to realize full-color rare-earth-free phosphors. Alkali-earth vanadates, Ca₂VO₄Cl and Sr₂VO₄Cl showed blue PL against UV irradiation, whereas Ba₂V₂O₇ and Mg₃(VO₄)₂ showed green and orangish yellow PL, respectively.

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We report fabrication and photoluminescence properties of sol-gel-derived white-light phosphors based on Al2O3-SiO2.

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The author reports the recent X-ray powder diffraction method and its application to the crystal-structure analysis of phosphor materials.

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We have been searching for new materials that exhibit a sensitization effect for rare-earth ions. In this way, we investigate Lanthanum scandium borate, in which the absorption of VUV light by the host may lead to efficient energy transfer to Gd³⁺.

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Examples of synthesis of a variety of silicate-based phosphors by aqueous solution processes using a novel water-soluble silicon compound are presented. An approach for parallel synthesis of silicates for efficient search for new phosphors and optimization of their composition is given.

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Oxygen sensor using yttria-stabilized-zirconia (YSZ) shows higher resistivity at lower temperature. The working temperature of oxygen gas sensor using epitaxial YSZ thin film deposited on (001) Si substrate was decreased drastically, e.g. 300oC. It might be the reason that thinner the film thickness reduces the internal resistivity of oxide ion conduction in YSZ. On the other hand, YSZ thin film received the residual stress by thermal expansion coefficient mismatch between thin film and the substrate. Activation energy values was calculated from the Arrenius plot of DC resistivity change along the film plane with different temperatures. There was a tendency that the activation energy slightly decreased with decrease of residual compressive stress along the YSZ thin film.

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The effects of small amount of transition metal ions on mechanical machining properties of oxide glasses have not been investigated enough. In our previous work, we have reported that the addition of a small amount of Co ion to soda-lime silicate glasses affected the mechanical machining properties of such glasses. In this study, the effects of Fe ion addition on mechanical machining properties of soda-lime silicate glasses were examined mainly from the change of polishing and cutting rates of those glasses. The structural change of the glasses obtained from UV-Vis. and IR spectroscopic measurements were also discussed.

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We reported on the down-conversion or up-conversion photoluminescence with different colors in lanthanide-doped bismuth titanate thin films prepared by chemical solution deposition. The doping lanthanide ions included Eu3+, Pr3+, Er3+, Ho3+, and Tm3+ ions. The photoluminescence can be further enhanced by constructing the composite thin films with ZnO nanorods or ZnO thin layers. The thin films also showed improved ferroelectricity after co-doping with other ions such as W6+, Yb3+ ions. The emission mechanisms were discussed. The results suggest that the lanthanide-doped bismuth titanate thin films can find applications in new multifunctional photoluminescence ferroelectric thin-film devices.

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There are many methods that can be used to prepare lanthanide-ion-doped nanomaterials, such as solid state reactions, sol-gel techniques, hydroxide precipitation, hydrothermal synthesis, spray pyrolysis, laser-heated evaporation and combustion synthesis, etc. We developed a novel solution process named "oleate-modified hydrothermal growth method,"and reported that well crystallized CeO2 and YVO4 nanoparticles exhibiting amphipathic property were successfully synthesized by this process. In the present study, we fabricated CePO4:Tb nano-particles. The obtained particles were nanorod in shape, 5 nm in diameter and 30 nm in length. Their size, crystallinity, fluorescent property were compared with those of samples fabricated by normal hydrothermal method.

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Lead Magnesium Niobate, Pb(Mg_1/3Nb_2/3)O3_{(PMN), is one of the most famous relaxor type ferroelectric material. Its epitaxial thin films were prepared by Metal Organic Decomposition (MOD) method for analysis of its local structure, polar nano region (PNR) and chemical order region (COR). We have searched the condition for the epitaxial growth. HRTEM and the derived strain analysis show that shifts of Pb atomic columns particularly in the <111> direction. This result infers the effect of random fields from random arrangement of Mg²⁺}and Nb5+ ions.

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We present a novel application of gelcasting in a strong magnetic field for texture development in Ti₃SiC₂. A low-toxic, water-soluble, monomer, synthesized by Mikolaz et.al was used. Gelcasting is an established ceramic forming process to produce high quality green bodies. Gelcasting in magnetic field has been tried for certain ceramics but not for the MAX phases. Grain oriented ceramics are gaining importance as prospective single crystal alternatives. Optimized gelcasting conditions render the texturing of Ti₃SiC₂ possible within a short exposure time in the magnetic field. Fabrication of highly textured dense green bodies of Ti₃SiC₂ with C-axis oriented perpendicular to the magnetic field was accomplished.

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