Ba_6Ti_2Nb_8O_(30)和Sr_6Ti_2Nb_8O_(30)陶瓷的驰豫铁电性能

Relaxor Properties of Ferroelectrics Ba_6Ti_2Nb_8O_(30) and Sr_6Ti_2Nb_8O_(30)

作者用固相烧结方法合成了具有充满型钨青铜结构的Ba6Ti2Nb8O30和Sr6Ti2Nb8O30陶瓷.不同频率下Ba6Ti2Nb8O30和Sr6Ti2Nb8O30陶瓷介电常数随温度的变化的规律表明,这两种陶瓷的铁电-顺电相变具有明显的驰豫铁电相变特征,相变弥散指数分别为1.95与1.41.它们在1MHz时的居里温度分别为155℃和160℃,两者的居里温度十分相近.同时,对其介电性能的电场可调性进行了初步研究.当外加电场为2kV/cm、频率为10kHz时,Ba6Ti2Nb8O30和Sr6Ti2Nb8O30陶瓷在铁电-顺电转变温度附近的最大介电常数可调度为2.8%和0.3%.

Ba_ 6 Ti_ 2 Nb_ 8 O_ 30 and Sr_ 6 Ti_ 2 Nb_ 8 O_ 30 ceramics with filled tungsten bronze structure have been synthesized usingconventional solid-state reaction process. Their permittivity as a function of temperature as well as dc bias (from 0 to 2kV/cm) at different frequency has been investigatedin order to explore their relaxor ferroelectric nature and tunability under small electrical field. The two present ceramics have close Curie temperature (155℃ for Ba_ 6 Ti_ 2 Nb_ 8 O_ 30 and 160℃ for Sr_ 6 Ti_ 2 ...