Oxide ionic and electronic conduction in Ni-doped LaGaO3-based oxide

Partial electronic conduction in Ni-doped LaGaO3-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. PO2 dependences of hole and electronic conduction decrease with increasing Ni content and it becomes almost PO21/12 and PO2−1/12, respectively, at 1073 K when 10 mol% Ni is doped to Ga site. The estimated transport number of oxide ion in Ni-doped LaGaO3 is always higher than 0.95 in PO2 range from 1 to 10−21 atm, which is the important PO2 range for fuel cell application. Therefore, the main charge carrier is still oxide ion in Ni-doped LaGaO3. Comparing with the partial electronic conduction in Co-doped sample, the electrolyte domain is wider on Ni-doped sample.