Oxide ionic and electronic conduction in Ni-doped LaGaO 3-based oxide

Abstract

Partial electronic conduction in Ni-doped LaGaO 3-based oxide was investigated by using the ion-blocking method. It was seen that the hole and the electronic conduction originated from doped Ni becomes dominant with decreasing temperature and also with increasing Ni content. P O 2 dependences of hole and electronic conduction decrease with increasing Ni content and it becomes almost P O 2 1/12 and P O 2 −1/12, respectively, at 1073 K when 10 mol% Ni is doped to Ga site. The estimated transport number of oxide ion in Ni-doped LaGaO 3 is always higher than 0.95 in P O 2 range from 1 to 10 −21 atm, which is the important P O 2 range for fuel cell application. Therefore, the main charge carrier is still oxide ion in Ni-doped LaGaO 3. Comparing with the partial electronic conduction in Co-doped sample, the electrolyte domain is wider on Ni-doped sample.