Ce3+ ions in ceria nanoparticles (NPs) play a role as reactive sites in the adsorption of silicate anions. However, the limited concentration of Ce3+ ions in ceria NPs remains a major challenge in this regard. Herein, we report a simple strategy to synthesize Ce3+-enriched core–shell ceria NPs for enhanced adsorption of silicate anions. To increase the overall Ce3+ concentration, a shell layer is composed of Ce3+-rich ultrasmall ceria NPs approximately 5 nm in size. The Ce3+ concentration of such core–shell ceria NPs is increased by 12.7–17.1% relative to that of the pristine ceria NPs, resulting in increased adsorption of silicate anions. The Freundlich model fits the observed adsorption isotherm well and the constants of adsorption capacity (KF) and adsorption intensity (1/n) indicate higher adsorption affinity of the core–shell ceria NPs for silicate anions. We attribute these improvements to the increased Ce3+ concentration contributed by the ultrasmall ceria coating. This strategy can be used for enhancing the reactivity of ceria materials.

Micro-tensile properties of hard and soft thin films, TiN and Au, were evaluated by directly measuring tensile strain in film tension using the micro-ESPI(electronic Speckle Pattern Interferometry) technique. Micro-tensile stress-strain curves for these films were obtained and the properties were determined. TiN thin film 1 μm thick and Au films with two different thicknesses (t=0.5 μm and 1 μm) were deposited onto the silicon wafers, respectively, and micro-tensile specimens wide 50, 100 and 200 μm were fabricated using micromachining. In-situ measurement of the micro-tensile strain during tensile loading was carried out using the subsequent strain measurement algorithm and the ESPI system developed in this study. The micro-tensile curves showed that TiN thin film was a linear-elastic material showing no plastic deformation and Au thin film was an elastic-plastic material showing significant plastic flow. Effect of the specimen dimensions on mechanical properties was examined. It was revealed that tensile strengths for both films were slightly increased with increasing specimen width. Furthermore, variations of yielding strengths for the thin film Au with change of the dimension were investigated.

Combinatorial chemistry was applied to the optimization of red phosphors used for plasma display panels. Quaternary and ternary combinatorial libraries were developed for (Y, Gd, Lu, Sc)BO3 and (Y, Gd)(BO3 PO4) systems. Our combinatorial chemistry system consists of solution-based combinatorial synthesis and characterization, enabling the swift scanning of luminance and of Commission Internationale de l'Eclairage (CIE) chromaticity under vacuum ultraviolet light excitation. As a consequence of the combinatorial approach, several new candidates were found to show higher luminance than the commercially available red phosphor for plasma display panels.

We have analyzed Tb L3-edge x-ray absorption near-edge structure spectra of Tb-doped phosphor compounds for plasma display panel applications. Intensity and lifetime of the green emission from the Tb3+:5D4→7F5 transition were measured with respect to nominal terbium concentration in the host compounds, i.e., YBO3, YPO4,and Y4Al2O9, all of which were made through the solid-state reaction. Typical concentration quenching was evident on the fluorescence intensity and the fluorescing level lifetime in our samples. From the analyses of white line absorption peaks at TbL3-edge, it was verified that terbium is essentially trivalent in all the samples, even invery highly concentrated ones. Thus, this implies that the concentration quenching was not caused by presence of mixed-valent states of terbium. Instead, it is believed that anonradiative energy transfer route among Tb3+ ions might be responsible for thebehavior.