BT-BKT无铅压电陶瓷的性能研究

通过在BaTiO3(BT)中加入不同含量的Bi0.5K0.5TiO3(BKT),研究了(1–x)BT-xBKT系无铅压电陶瓷的性能特征。经1200℃空气气氛2～4h烧结的陶瓷形成了钙钛矿结构固溶体单一相。陶瓷的介电、压电、铁电性质受BKT含量的影响显著。随着BKT的加入,陶瓷表现出一定的弛豫型铁电体特征。当x为0.20时,陶瓷具有较小的tanδ,并且介电性能稳定。tC及EC随BKT添加量的增加而增大。当x为0.20时,陶瓷的tC达182℃,d33达到63pC/N;x为0.10时,Pr达最大值9.4×10–6C/cm2。

Dielectric and piezoelectric properties of BT-BKT lead-free piezoceramics

Lead-free (1-x)BaTiO3-xBi0.5K0.5TiO3 (x=0.09,0.1,0.11,0.12,0.13,0.15,0.18,0.25,0.30) piezoelectric ceramics were fabricated by sintering at 1 200 ℃ for 2～4 h in air atmosphere. The crystal structure was investigated by X-ray diffraction. The dielectric,ferroelectric and piezoelectric properties were also studied. The ceramics with different content of BKT formed single-phase solid solutions with perovskite structure. As the addition of BKT,the ceramics show a relaxor behavior. When x =0.2,the ceramic has stable permittivity and low dielectric losses. The piezoelectric constant d33 of the ceramic is 63 pC/N. The highest Curie temperature,about 182 ℃,is obtained when x=0.20. The largest value of remnant polarization,Pr=9.4×10-6 C /cm2,is obtained when x=0.10,whereas the coercive field,increased monotonously as the BKT content increased.