Ce改性0.9Bi_4Ti_3O_(12)-0.1SrBi_2Nb_2O_9铋层状铁电陶瓷结构与性能

Microstructure and Electrical Properties of Cerium-modified Bismuth-Layer 0.9Bi_4Ti_3O_(12)-0.1SrBi_2Nb_2O_9 Ferroelectric Ceramics

采用固相法制备了CeO_2掺杂改性的0.9Bi_4Ti_3O_(12)-0.1SrBi_2Nb_2O_9(BIT-SBN)铋层状铁电陶瓷材料。系统研究了CeO_2掺杂对BIT-SBN基陶瓷物相结构、微观结构以及电性能的影响。结果表明:所有陶瓷样品均为单一的铋层状结构,样品的晶粒尺寸随着CeO_2掺杂量的增加而逐渐增大,并且沿a-b面的生长速度明显大于沿垂直c轴方向的生长速度;BIT-SBN基陶瓷的压电性能随着CeO_2的掺杂而显著提高,损耗明显降低。当CeO_2掺量为0.75 wt%时,样品具有最佳的电性能:压电常数d_(33)=28 pC/N,介电损耗tanδ=0.20%,机械品质因数Q_m=3015,居里温度T_C=595℃;并且此时样品具有良好的热稳定性,在高温器件领域具有一定的应用潜能。

The cerium modified bismuth-Layer 0.9Bi_4Ti_3O_12-0.1SrBi_2Nb_2O_9（BIT- SBN） ferroelectric ceramics were synthesized using conventional solid state processing.The effects of cerium addition on the microstructure and electrical properties of ceramics have been investigated in details.It was found that the ceramics possess a pure bismuth- layer structure,the addition of CeO_2 enhanced the grain growth of the ceramics and the growth velocity of the direction along the a-b plane is much larger than that of the direction along the c axis.The piezoelectric properties of BITSBN based ceramics were significantly enhanced and the dielectric loss decreased after cerium doping.The piezoelectric constant d_33,dielectric loss tan5,mechanical quality factor Q_m for the BIT-SBN ceramics with 0.75 wt%CeO_2modification was found to be 28pC/N,0.20%,3015,respectively,together with the high T_c（-595 °C） and stable piezoelectric properties,demonstrating that the BIT-SBN-x=0.75 ferroelectric ceramics are the promising candidates for high temperature applications.