The transport properties of mayenite-based materials, Ca12Al14O33, were investigated. Systems studied included H-doped/ UV-irradiated Ca12Al14O33, Ca(12-x)MgxAl14O33 (x = 0.1, 0.3, 0.5, 0.8, 1) and Ca12Al(14-x)SixO(33+x/2) (x = 1, 2, 3, 4). The as-prepared Ca12Al14O33 exhibited a room temperature electronic conductivity on the order of 10^-10 S/cm, and a high temperature...