Effect of synthesized BaTiO_3 doping on the dielectric properties of ultra temperature-stable ceramics

摘要

The high performance X9R ceramics could be sintered at as low as 1,120 ℃ by doping 3 mol% synthesized BaTiO_3 (SB) additives into the BaTiO_3-based ceramics, with a dielectric constant greater than 2,200 at 25 ℃ and dielectric loss lower than 1.7 %. The effects of SB additives on the micro-structure and dielectric properties of BaTiO_3-based ceramics were investigated. The dielectric constant of BaTiO_3-based ceramics doped with 3 mol% SB was increased due to the promotion of the densification of ceramics. With SB content up to 4.5 mol%, Ti~(4+)'s polarization was depressed, which resulted in the decrease of augmented dielectric constant at 25 ℃. The partial solid solution was formed between Pb(Ti, Sn)O_3 and BaTiO_3, and the substitutions of Pb at A-sites and Sn at B-sites were existed. The strengthen of Ti-0 bonds and higher Curie point of Pb(Ti_(0.55)Sn_(0.45)O_3 was helpful to increased the Curie point of the ceramics effectively. Doped with SB additives, the volume of ferroelectric core was increased, and the sharp peak intensity at Curie point was increased accordingly. Capacitance temperature characteristics was improved attributed to the mutual effects of SB and Pb(Ti_(0.55)Sn_(0.45))O_3. The formation of core-shell structure was sensitive to the sintering temperature, so the dielectric properties of ceramics were highly depended on the sintering temperature.