High temperature piezoelectric response of polycrystalline Li-doped (K,Na)NbO3 ceramics under compressive stress
High temperature piezoelectric response of polycrystalline Li-doped (K,Na)NbO3 ceramics under compressive stress
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DOI：
10.1063/1.5134554
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发表时间：
2020-03
影响因子：
3.2
通讯作者：
Alexander Martin;N. Khansur;U. Eckstein;K. Riess;K. Kakimoto;K. Webber
中科院分区：
文献类型：
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作者：
Alexander Martin;N. Khansur;U. Eckstein;K. Riess;K. Kakimoto;K. Webber
研究了单轴压应力对多晶Li改性（K 0. 5 Na 0. 5）NbO 3（0，2，4 mol. %的Li）表征为25至450 °C的温度的函数。这些数据揭示了在（KxNa 1 − x）NbO 3中众所周知的结构相变附近的介电和压电特性的相应异常。特别是，增加的应力被发现将正交-四方（T O − T）和四方-立方（T C）相边界移动到更高的温度，从而稳定了较低的对称相。实验结果还表明，应力达到一个临界值，压电响应低于T O-T，以上的单调下降观察。相比之下，介电常数随着应力的增加而增加到T O − T以下。这些结果被用来构建一个应力-温度相图的锂改性（K0.5Na0.5）NbO 3。
The influence of uniaxial compressive stress on small-signal relative permittivity and direct piezoelectric coefficient of polycrystalline Li-modified (K0.5Na0.5)NbO3 (0, 2, and 4 mol. % Li) was characterized as a function of temperature from 25 to 450 °C. These data reveal corresponding anomalies in both the dielectric and piezoelectric properties near the well-known structural phase transitions in (KxNa1 − x)NbO3. In particular, increasing stress was found to shift the orthorhombic–tetragonal ( T O − T) and tetragonal–cubic ( T C) phase boundaries to higher temperatures, thereby stabilizing the lower symmetry phases. Experimental results also show that stress up to a critical value flattens the piezoelectric response below T O − T, above which a monotonic decrease is observed. In contrast, permittivity is increased below T O − T with increasing stress. These results are used to construct a stress–temperature phase diagram of Li-modified (K0.5Na0.5)NbO3.