Dielectric properties of the (Nb1 − xTax)2O5 solid solution

Nb2O5 in the high niobia structure type can accommodate approximately 25% partial substitution of Ta for Nb in a solid solution. Here we report the dielectric properties of polycrystalline ceramics of (Nb1 − xTax)2O5, 0.0 ≤ x ≤ 0.25, in the frequency range 1kHz–3MHz, in the vicinity of ambient temperature. The substitution of even small quantities of Ta for Nb greatly enhances the dielectric constants, reaching a maximum of approximately 180 at ambient temperature for x = 0.15.