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Core-shell particles were obtained via the layer-by-layer assembly of oppositely charged polyelectrolytes on the colloidal templates. Not only polyelectrolytes but also a number of materials having multivalent charge are applicable for the layer-by-layer assembly technique. Heteropolyacids also have multivalent charge and comprise a structurally diverse class of inorganic transition metal oxygen clusters which owing to their unique electronic properties hold promise for a host of technological applications such as heterogeneous catalysts, proton conductors, etc. In this study, hybrid core-shell particles formed with multilayer of polyelectrolytes and heteropolyacids were prepared via the layer-by-layer assembly technique. The obtained particles were characterized by FT-IR, electrophoretic mobility, and electron microscope. In addition, their assemblage property was also investigated.

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Ink-jet and spray technology have been successfully used to fabricate ceria and titania film/pattern on glass substrate at 2750C to 400oC. Precursor solution was ink-jetted or sprayed towards heated substrate. When droplets of the precursor solution hit the substrate, precursor started to decompose and nucleation & growth of the film occurred. X-ray diffraction (XRD) revealed the formed phases are crystallized and consisted of 10~20 nm size crystallites. Minimum width of the patterns that could be prepared by ink-jet deposition was 120 mm and thickness was about 420nm. Adhesion property of fabricated films to the substrate was also good.

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High-temperature phase transition of lanthanum aluminum titanate La_0.68(Ti_0.95,Al_0.05)O₃ has been studied using neutron powder diffraction and Rietveld method. The material is orthorhombic with space group Cmmm between 25 and 286C, while it is tetragonal with space group P4/mmm between 388 and 592C. The anti-phase tilt angle along b axis of the oxygen octahedron around Ti and Al atoms was found to induce the tetragonal-to-orthorhombic phase transition. The axial _b/a ratio decreases with an increase of temperature and becomes unity at the transition temperature between 286 and 388C.

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Structural change in the oxide-ion conductor, zirconia-scandia solid solution was studied by a combined technique of Rietveld method, MEM analysis and MPF method. Spatial distribution and disorder of oxide ions were investigated using the nuclear density distribution.

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Crystal structures of SrAl2O4, BaAl2O4 and their solid solutions have been reviewed in terms of the linkage pattern of [AlO4] tetrahedra. With SrAl2O4 the hexagonal-to-monoclinic phase transformation occurs at 950K during cooling. The space group change from P63 to its subgroup P21 eliminates the triad axis of the former phase, which involves a reduction in the symmetry of the trigonally distorted rings. The hexagonal structures of SrAl2O4 and BaAl2O4 differ distinctly in the linkage pattern of the [AlO4] tetrahedra. In the former structure, all of the tetrahedral rings are equivalent. In the latter, there are two types of tetrahedral rings; trigonal rings and asymmetrical ones. The trigonal rings, comprising 25% of the total number of rings, contain in their centers the Ba atoms with the special position. This implies that the triad axes exist in the centers of the rings, and hence they are distorted trigonally as in the hexagonal SrAl2O4. On the other hand, the Ba atoms in the asymmetrical rings are located at the general position site. The structural disorder in Ba0.6Sr0.4Al2O4 (space group P6322) was investigated by the combined use of Rietveld method and maximum-entropy method. The electron density distribution was satisfactorily expressed by the split-atom model, in which the strontium/barium and oxygen atoms were split to occupy the lower symmetry sites.

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The crystal structure of zirconium oxide nanoparticles was refined by the Rietveld analysis of synchrotron X-ray powder diffraction data measured at 298 K. In the nanoparticles, there existed two phases of tetragonal ZrO_2-d (average particle size: 11+-2 nm) and monoclinic ZrO₂ (average particle size: 24+-4 nm) where the weight fractions were estimated to be 84.9 and 15.1 wt%, respectively. The structural refinement suggests that the tetragonal ZrO_2-d has oxygen deficiency (d=0.031(7)) and that the monoclinic ZrO_2-d has less oxygen deficiency (d=0), where the d is the vacancy concentration. The monoclinic ZrO2 has a larger unit-cell volume.

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We found a new phase of BaLaMnO₄. The single crystal with tetragonal structure (I4/mmm) was made by a floating zone (FZ) method in an Ar atmosphere. After that, the crystal was annealed at 773 K for 168 h in 1% H₂-Ar atmosphere and cooled slowly to room temperature. The crystal possessed a new phase with an orthorhombic structure (Cccm as possibility) by XRD and TEM. The orthorhombic structure transformed into a tetragonal phase by heating using a thermal TEM. The structural change might be controlled by a tilting of octahedron MnO₆ accompanied by changing of nonstoichiometry.

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sapphire surfaces with c-plane were polished using several kinds of diamond slurry and colloidal silica, and the introduced damaged zones were investigated using TEM, HRTEM and TEM-CBED.

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Residual stresses occurred by transformation form tetragonal to monoclinic phase of 3Y-TZP in low temperature aging has been analyzed by using Raman spectroscopy. Process of residual stress during transformation form surface to inside and the occurred residual stresses has been discussed in this study. Also effective depth resolution of laser probe was measured directly, and we discussed the accuracy of this method and the spectroscopic applications for transformation analysis of 3Y-TZP.

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The reflection (r) intensity measurement with non-contact probe was carried out for measuring the ferroelectric and dielectric distribution in the dielectric materials. In order to obtain the microscopic dielectric distribution, analysis and adjustment of spatial resolution were carried out. The r intensity was measured as a function of distance between sample and probe. The sample was selected for BaTiO3 and MLCC. In analysis, the spatial resolution was calculated using Bethe's theory based on Kirchihoff's diffraction theory. From r intensity mapping measured with probe, dielectric permittivity distribution was investigated, and experimental spatial resolution was tried to estimated and compared with theoretical calculation.

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Carrier transport and thermoelectric properties of (Sr_1-xEu_x)TiO₃ (x = 0.05 ~ 1.0) dense ceramics were measured at high temperatures (300 ~ 1000K) to clarify the role of Eu²⁺ ion in SrTiO₃ lattice. Although the unintentionally doped SrTiO₃ (reduced) exhibited degenerated conduction behavior, carrier concentration of the Eu-substituted samples increased with temperature (Ea ~ 1 eV), which indicates that Eu ion plays a carrier generator. Figure of merit ZT of the (Sr_1-xEu_x)TiO₃ ceramics was, drastically increased with temperature and reached ZT ~ 0.15at 1000 K.

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We investigated Ca doping effect on thermoelectric property of SrFeO3-d perovskite. The Seebeck coefficient values of all the samples were positive, indicating p-type conduction. Doping with Ca in SrFeO3-d enhanced the Seebeck coefficient. The Seebeck coefficients increased with temperature for the samples with x = 0, 0.25, 0.33 and 0.5, while the Seebeck coefficients decreased with increasing temperature for the sample with x = 1.0.

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We find that nonstoichiometric orthorhombic titanium oxides (TiO_x; x=1.86-1.94) obtained by reducing the anatase titanium oxide in H₂ at 950C show large thermoelectric power. Their Seebeck coefficients are in the range of -0.060 to -0.518 mV/K. The figure of merit (ZT) for TiO_1.94 at 70C is estimated at 0.195. Theoretical discussions are made based on the assumption that the entropy current due to the electronic spin entropy controls the thermoelectric power. The nonstoichiometric orthorhombic titanium oxides, containing no hazardous elements, are promising materials for thermoelectric power generation.

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Al-doped ZnO is known as an excellent n-type thermoelectric material. Samples were prepared by Spark Plasma Sintering method and pressureless sintering method to evaluate the thermoelectric properties in this study. Dense material (relative density > 95%) prepared by pressureless sintering had high electric conductivity and high thermal conductivity. On the other hand, Spark Plasma Sintered material gave high electric conductivity and low thermal conductivity at the lower density (~80%).

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Cs₅(HSO₄)₃(H₂PO₄)₂ and Cs₃(HSO₄)₂(H₂PO₄) were formed from mixtures of CsHSO₄ and CsH₂PO₄ by mechanochemical treatment using a planetary ball mill. These compounds showed high proton conductivity from room temperature to medium temperature. In this study, proton conductivities of Cs-containing solid acid composites, which were prepared from Cs-compounds and metal oxides by mechanical milling, have been investigated.

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