Thermal depoling process and piezoelectric properties of bismuth sodium titanate ceramics
Thermal depoling process and piezoelectric properties of bismuth sodium titanate ceramics
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DOI：
10.1063/1.3115409
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发表时间：
2009-04-15
影响因子：
3.2
通讯作者：
Takenaka, Tadashi
中科院分区：
文献类型：
--
作者：
Hiruma, Yuji;Nagata, Hajime;Takenaka, Tadashi
采用传统的陶瓷制备工艺制备了化学计量比和非化学计量比的（Bi0.5Na0.5）TiO 3（BNT）陶瓷。研究表明，BNT陶瓷的高电导率与烧结过程中Bi的挥发有关。X射线研究表明，在BNT陶瓷和BNT单晶中，在330至480摄氏度之间的温度范围内存在四方相。此外，从使用未极化和极化样品的介电性质的温度依赖性，确定退极化温度Td、菱形-四面体相变温度TR-T和最大介电常数的温度T-m分别为187、约300和325 ℃。采用全极化的BNT陶瓷测量了所有振动模式的压电性能和压电性能的温度依赖性。从退火对极化样品的场致应变、X射线衍射图和介电常数的影响来看，BNT陶瓷在T-d、T-d和TR-T之间以及TR-T和T-m之间表现出三种热退极化过程。
Stoichiometric and nonstoichiometric (Bi0.5Na0.5)TiO3 (BNT) ceramics were prepared by a conventional ceramic fabrication process. This study revealed that the high conductivity of BNT ceramics is associated with Bi vaporization during sintering. An x-ray study revealed that a tetragonal phase exists in the temperature range between 330 and 480 degrees C in BNT ceramic as well as BNT single crystals. In addition, the depolarization temperature T-d, rhombohedral-tetragonal phase transition temperature TR-T, and the temperature T-m of the maximum dielectric constant were determined to be 187, approximately 300, and 325 degrees C, respectively, from the temperature dependences of dielectric properties using unpoled and poled specimens. The piezoelectric properties of all vibration modes and the temperature dependences of the piezoelectric properties were measured using fully poled BNT ceramics. It was also revealed that BNT ceramics exhibit three thermal depoling processes at T-d, between T-d and TR-T, and between TR-T and T-m from the effects of annealing on the field-induced strain, x-ray diffraction patterns, and dielectric constant of poled specimens.