Apatite-phase synthesis from interdiffusion in doped CeO2-SiO2 thin-film superlattices and in situ conductivity studies

摘要

Cerium silicate oxy-apatite thin films have been fabricated starting from nanoscale Gd-doped ceria-silica superlattices. In situ conductivity measurements were performed in a high-temperature controlled-environment probe station to directly monitor phase formation and stability regions. GdxCe9.33-x(SiO4)(6)O-2 +/-delta exhibited a total electrical conductivity of similar to 10(-2) S/cm at 1150 K in reducing ambient (pO(2)approximate to 10(-17) atmosphere). Structural studies by X-ray diffraction and transmission electron microscopy were correlated to electrical conductivity measurements. The results indicate potential for applications in energy technologies as well as demonstrate a route to synthesize ultrathin complex oxides through interfacial reactions.