DIELECTRIC-PROPERTIES OF TIO2-NB2O CRYSTALLOGRAPHIC SHEAR STRUCTURES

The dielectric constants (K) have been measured near ambient temperatu re for polycrystalline bulk ceramics of the crystallographic shear com pounds TiNb24O62, Ti2Nb10O29, and TiNb2O7. These show enhanced K's ove r Nb2O5 and TiO2, with the 2:10:29 phase displaying an ambient tempera ture K of approximately 130. We also report the effects of partial sub stitution of Nb by Ta. In general, thr dielectric constants are enhanc ed for 5-10% Ta substitution with the detailed behavior differing for the three phases.