Samarium-doped anatase TiO 2 (A-TiO 2 :Sm) and rutile (R-TiO 2 :Sm) single phase thin films are fabricated by laser ablation and post-annealing at different temperatures. A-TiO 2 :Sm samples exhibit intense PL emission, whilst R-TiO 2 :Sm samples exhibit weak PL emission. The local crystal structure of Sm-dopants is investigated using X-ray absorption fine structure (XAFS) measurements. The thin films showing strong PL emission have lower crystal symmetry than the other samples, which show weak PL emission. We report the relationship between changing the symmetry of the local structure and activation of the luminescent center. The local structure of Sm 3+ thin films annealed at 600˚C to 800˚C, which possess an activated semi-stable Sm 3+ ions luminescent center, dramatically changes from having high symmetry to low symmetry. While the phase transitioned R-TiO 2 :Sm and fabricated as R-TiO 2 :Sm samples showed highly symmetric. Hence, the coordination around the doped-Sm 3+ ions is the key factor for exhibiting an intense PL emission. Therefore, activation of the luminescent center is strongly connected with the distorted local crystal symmetry, which is proposed as one of the factors defining the transfer probability. In this work, we discuss the connection between coordination around Sm 3+ ions and PL intensity, and optical and electrical properties of a n +-ITO/TiO 2 :Sm/p-NiO/p +-Si hetero junction LED preparing with optimal fabricating condition.

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The precipitation titration of sodium chloride with electrogenerated silver ion was studied. The production of a precipitate of silver chloride had a significant effect on the titration results because the precipitate involved unreacted chloride or unreacted silver ion. The accuracy of the method was investigated by changing the introduction time of a sodium chloride solution to the coulometric cell during the process of electrolysis, and examining the dependency on the sample size. The accuracy of the measurement of the precipitation titration is discussed.

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The ionic conductivity of a solid electrolyte for sodium-ion batteries is a hot topic nowadays. The lattice distortion introduced into the solid electrolyte produces high ionic conductivity. In this work, we attempted to introduce lattice distortion into Na3OBr, a solid electrolyte for the sodium-ion batteries, by synthesizing Na3O1-SBr in which the oxygen ions are partially replaced by sulfur ions. The solid electrolyte Na3OBr has anti-perovskite structure, which makes it easy to manipulate the crystal structure. We have succeeded in synthesizing high purity Na3O1-SBr (=0 ,0.05 ,0.1 ,0.15 ,0.2). The lattice distortions have been introduced to Na3OBr.