Thin films were prepared by using a vacuum evaporation process. The use of X-ray analysis showed that the films were polycrystalline, with an hexagonal crystal lattice and preferred growth in the c-direction. Transport studies showed that the material was ionically conducting; the conductivity being due to I-ion vacancy motion, with an activation energy of 0.29eV and an ionic transference number greater than 0.99.

T.A.Kuku: Thin Solid Films, 1998, 325[1-2], 246-50