Dielectric properties of barium titanium niobates

The results of measurements of dielectric constants, in the vicinity of ambient temperature, are presented for eight barium titanium niobium oxides (BaTi_1+2nNb₄O_13+4n for n = 0, 1, 2, 3, 4; Ba₃Ti₄Nb₄O₂₁, Ba₃Ti₅Nb₆O₂₈, and Ba₆Ti₂Nb₈O₃₀) in polycrystalline ceramic form. The dielectric constants are in the range of 30 to 70. The results of dielectric measurements on solid solutions obtained by partial substitution of Ta for Nb are also reported. These substitutions do not dramatically increase the dielectric constants. One material, Ta-substituted Ba₃Ti₅Nb₆O₂₈, has a very low temperature coefficient of dielectric constant at K ≈ 45.