烧结工艺对B2O3掺杂Ba1-xSrxTiO3梯度陶瓷介电性能的影响

研究了烧结温度及升温速率对氧化硼(B₂O₃)掺杂钛酸锶钡梯度陶瓷(Ba_1-xSr_xTiO₃,x=0-0.4,步长0.02)的致密化、晶粒尺寸及介电性能的影响.结果表明,随着烧结温度的升高,在氧化硼挥发的同时致密化程度提高,从而居里峰提高且变得尖锐;随着氧化硼含量的增加,晶粒尺寸均匀长大、介电常数和介电损耗都增加;升温速率适中时,掺杂物的挥发、致密化进程及晶粒长大同步完成,梯度陶瓷介电性能才有效提高.此外,钛酸锶钡梯度陶瓷掺杂适量氧化硼明显降低烧结温度,比未掺杂相同成分的陶瓷烧结温度至少降低150℃,且介电损耗明显减小;梯度陶瓷的居里峰温度区间显著展宽,大大降低了该温区的介温系数,可望提高该系列陶瓷元器件精度及稳定性.

Effect of Sintering Process on Dielectric Properties of B2O3-doped Ba1-xSrxTiO3 Graded Ceramics

Effect of sintering temperature and heating rate on densification, grain size and dielectric properties of B_2O_3-doped Ba_1-xSr_xTiO₃(x=0～0.4, in step of 0.02) graded ceramics was investigated. With the increase of sintering temperature, B₂O₃ volatilization and densification improvement resulted in Curie peak elevated and sharpened. With the increasing of dopant content, grains grew up uniformly, and dielectric constant and loss increased. While dopant volatilization, densification process and grain growth were fulfilled synchronously with appropriate heating rate, which conduces to the dielectric improvement and dielectric loss reduction for the graded ceramics. In addition, B₂O₃ doping lowered at least 150℃ of the sintering temperature, and the dielectric loss was reduced obviously; Curie peak was broadened and flattened remarkably and the temperature coefficient of permittivity was decreased greatly, which means the accuracy and stability of components with such material can be improved.