Dense sintered bodies of proton conducting BaZrO 3 (BZ) and Y-doped BaZrO 3 (BZ-Y) were obtained at 1600˚C for a short sintering time of 5 hours, by the addition of NiO as a sintering promotion agent. The relative density and grain growth of samples, Ni-doped BaZrO 3 (BZ-N) and Ni, Y co-doped BaZrO 3 (BZ-NY), were increased with increasing Ni addition. The sinterability of BZ-NY was greatly improved just to add only 0.6 mol% Ni and the relative density of this sample was more than 98%, in contrast to that of 60% at most for BZ-Y without Ni addition. Electrical conductivity of BZ-NY added Ni 1.0 mol%, BaZr 0.91 Ni 0.01 Y 0.08 O 3-α , was more than 10 −3 S•cm −2 at 900˚C in a wet 1% hydrogen atmosphere, which value was 10 times higher than that of BZ-Y. In addition, the kind of electrical conduction carrier and an ionic transport number were also examined by employing various concentration cells. It was found that the proton conduction was dominant for both BZ-N and BZ-NY samples, although BZ-NY showed scarcely oxygen-ion conduction approximately 10% in a high temperature range higher than 800˚C. From these results, as mall amount of Ni addition found to be effective for improvement of both the sinterability and the electrical conductivity.

The luminescence properties of Eu2+-doped barium calcium silicon oxynitrides (general formula: Ba4-xCaxSi6ON10: Eu2+ (x= 1.8 ~ 2.2)) were examined, together with the preparation conditions for the solid state reaction. Firstly, the stoichiometric amounts of Ba, Ca3N2, SiO2 and Si3N4 were mixed with Eu2O3 (activator; the molar ratios of Eu to (Ca + Ba + Eu) (= m; 0.05 to 1.0)) for the preparation of Ba1.8Ca2.2Si6ON10: Eu2+, Ba2.0Ca2.0Si6ON10: Eu2+ and Ba2.2Ca1.8Si6ON10: Eu2+, and then the mixtures were heated at a temperature between 1300 and 1550°C for 10 h in N2 atmosphere. The single phase compounds, which were prepared by the heating at and above 1350°C, emitted the red color light whose wavelength could be changed from 638 to 653 nm with increasing m value from 0.05 to 1.00, due to the excitation at the wavelength of 528 nm.