The behavior of O vacancies in Ni-doped barium strontium titanate ceramics was monitored by means of thermally stimulated current measurements at up to 200C. The observations confirmed that the vacancies drifted due to a high electric field, at high temperatures, and piled up under the cathode electrode. The initial complex defects of acceptor, NiTi”, and donor, VO”, type were separated from each other so as to form a forward-biased pn junction. It was also revealed that the O vacancies were newly generated at the anode area if the ceramic surface was roughened, or if a catalytic electrode such as Pt was attached.

Generation and Dynamic Behaviors of Oxygen Vacancies in Barium Strontium Titanate Ceramics. T.Fukami, D.Agawa, N.Bamba: Japanese Journal of Applied Physics - 1, 2001, 40[9B], 5634-7