Peroxo-polytantalic acid, Ta2O5nH2O, was prepared by the direct reaction of Ta(OC2H5) with H2O2. By using water-based solutions, amorphous thin films of excellent homogeneity could be deposited onto glass substrates by using conventional spin-coating techniques. The electrical conductivities of such samples were measured by using an alternating current impedance method. This revealed that the temperature and humidity dependences of the ionic conductivity (about 4 x 10-5S/cm at 20C) were quite small.

Y.Sone, A.Kishimoto, T.Kudo: Solid State Ionics, 1993, 66[1-2], 53-9