Effect of Sn⁴⁺ and W⁶⁺ substitution on the dielectric properties of Bi₂O₃–ZnO–Nb₂O₅-based low firing ceramics

As a promising candidate for thermostable Low-temperature co-fired ceramic material with NP0 characteristic, (Bi_1.8Zn_0.2)(Zn_0.6Nb_1.4−2xSn _x W _x )O₇ (x = 0.00, 0.02, 0.05, 0.10) dielectric ceramics with improved dielectric properties were prepared by conventional mixed oxide route. The effect of the chemical substitution of Sn⁴⁺ and W⁶⁺ cations on the structure and dielectric properties in this system had been investigated systematically. The Sn⁴⁺ and W⁶⁺ co-substitution was tentatively introduced in cubic-monoclinic pyrochlores co-existing ceramics and the results showed regular influence on the structure, dielectric properties with the amount of substitution. With the structure evaluation and electrical properties measurement results, the Sn⁴⁺ and W⁶⁺ substituted Nb⁵⁺ in B site showed an effective way to depress the grain growth and the ceramic with fine grains in 1–3 μm that can be obtained at a low sintering temperature of 950 °C. Based on these results, small amount of Sn⁴⁺ and W⁶⁺ substitution was successfully applied to a base ceramic with the electrical properties, which can be a promising candidate for LTCC and multilayer components applications in high frequency and microwave range.