Electric fatigue process in lead-free alkali niobate ceramics at various pressures and temperatures
Electric fatigue process in lead-free alkali niobate ceramics at various pressures and temperatures
复制标题
DOI：
10.7567/jjap.54.10nb06
复制
发表时间：
2015-09
影响因子：
1.5
通讯作者：
Alexander Martin;K. Kakimoto
中科院分区：
文献类型：
--
作者：
Alexander Martin;K. Kakimoto
电疲劳试验是评价压电陶瓷可靠性的重要手段。然而，到目前为止，这些测试并不是无铅碱式铌酸盐(NKN)陶瓷研究的重点。为此，对Li0.06Na0.47K0.47NbO_3(LNKN_6)和Na_(0.55)K_(0.45)NbO_3+0.25%MnO(Mn-NKN)两种不同材料在不同的单轴压力范围内(0.1~100 Mpa)和不同的温度范围(室温~150℃)进行了测试。结果表明，较硬的铁电材料Mn-NKN在压力高达25 Mpa时仍能保持其压电性。当压力超过∼30 Mpa时，发生双极疲劳时，样品发生去极化并形成微裂纹。相比之下，较软的LNKN6在25至50兆帕的较高压力下不会表现出疲劳。然而，在这两种材料中，较高的温度增强了畴壁和电荷载流子的运动，并最终促进了畴壁的钉扎。
Electric fatigue tests are important for evaluating the reliability of piezoceramics. However, these tests have not been the focus of studies of lead-free alkali niobate (NKN) ceramics so far. For this purpose, two different materials, Li0.06Na0.47K0.47NbO3 (LNKN6) and Na0.55K0.45NbO3 + 0.25% MnO (Mn-NKN), have been examined at various uniaxial pressures ranging from 0.1 to 100 MPa and various temperatures ranging from room temperature to 150 °C. It was shown that the harder ferroelectric Mn-NKN could maintain its piezoelectric properties at pressures up to 25 MPa. When bipolar fatigue occurred under pressures over the coercive stress of ∼30 MPa, the sample depolarized and formed microcracks. In contrast, the softer LNKN6 did not show fatigue at higher pressures between 25 and 50 MPa. However, in both materials, higher temperatures enhanced domain wall and charge carrier movements and conclusively domain wall pinning.