The shrinking process and microwave dielectric properties of BaCu(B2O5)-added 0.85BaTi4O9–0.15BaZn2Ti4O11 ceramics

•The low temperature sintered BaTi4O9–BaZn2Ti4O11 ceramics were prepared.•The liquid phase sintering mechanism was formed by the meltdown of BaCu(B2O5).•The dynamic shrinkage progress was presented by DIL and SEM characterization.•The sample sintered at 900 °C showed good microwave dielectric properties.•The relatively high Q × f = 20,200 GHz was the advantage of our prepared sample.

The effect of BaCu(B2O5) (BCB2) addition on the shrinking process and microwave dielectric properties of 0.85BaTi4O9–0.15BaZn2Ti4O11 (BZT) ceramics were investigated by the conventional solid-state ceramic route. Adding BaCu(B2O5) into 0.85BaTi4O9–0.15BaZn2Ti4O11 ceramics led to the formation of two new phases: Ba4Ti13O30 and BaTi(BO3)2. The densification of the 5–15 wt% BaCu(B2O5) + BaTi4O9–BaZn2Ti4O11 ceramics sintered at approximate 900 °C for 2 h was attributed to the liquid phase sintering mechanism formed by the meltdown of BaCu(B2O5). The addition of BaCu(B2O5) also increased the shrinkage rate and promoted the grain growth. Because of the improved densification, the dielectric constant of the samples sintered at 900 °C was increased from 29.5 to 32.2 with increasing BCB2 from 5 wt% to 15 wt%. However, the Q × f value decreased sharply from 27,600 GHz to 15,900 GHz due to the progressively increased Ba4Ti13O30 as well as the whisker glass phase. At last, good microwave dielectric properties with values of ϵr = 30.9, Q × f = 20,200 GHz and τf = +11.7 ppm/°C were obtained in the BZT ceramics with 11 wt% BCB2 sintered at 900 °C for 2 h. It was suitable for the low temperature co-fired ceramics (LTCC) applications.

Graphical abstractThe shrinkage of BZT and 11 wt% BCB2 + BZT ceramics sintered at 700–1250 °C.Figure optionsDownload full-size imageDownload as PowerPoint slide