高密度BiFeO3陶瓷的制备与介电性能

摘要

Single phase multiferroic BiFeO3 powders with different paticle sizes were synthesized by solid state sintering. BiFeO3 ceramics were then prepared by sintering the prepared BiFeO3 powders using the spark plasma sintering (SPS) method. The dielectric properties of the prepared BiFeO3 ceramics were studied. The results show that the prepared BiFeO3 ceramics is single phase material with high packing density. Its relative density reaches 97.3％, while its piezoelectric coefficient d33 is 13.6 pC/N. After annealing in oxygen, the prepared BiFeO3 ceramics shows markedly frequency dispersion and dielectric relaxation following the Arrhenius law at both low and high temperatures. However,after annealing in vacuum, the prepared BiFeO3 ceramics does not show dielectric relaxation any more at low temperatures.%采用固相烧结法制得了不同粒径的铁酸铋(BiFeO3)粉末,随后,采用混杂工艺与放电等离子烧结技术(SPS)结合的方法对BiFeO3单相粉末进行二次烧结,制得了BiFeO3陶瓷.研究了所制陶瓷的介电性能.结果表明,所制BiFeO3陶瓷具有很好的相组织及致密的结构,其相对密度达到97.3%,压电系数d33为13.6 pC/N.经氧气退火处理后,BiFeO3陶瓷具有明显的介电频率弥散及高温与低温两个阶段的介电弛豫行为;但经真空退火处理后,陶瓷的低温介电弛豫现象消失.