Materials with the magnetoplumbite structure were prepared by using high-temperature sintering techniques. Impedance data for ceramic samples, using Pt electrodes, revealed an intra-granular ionic (La3+) conductivity with activation energies of 2.5 and 1.6eV for Al11LaO18 and Al12LaO18N, respectively. The conductivities at about 1540K were of the order of 3 x 10-5S/cm.

T.E.Warner, D.J.Fray, A.Davies: Solid State Ionics, 1996, 92[1-2], 99-101