The influence of excess K2O on the electrical properties of (K,Na)1/2Bi1/2TiO3 ceramics
The influence of excess K2O on the electrical properties of (K,Na)1/2Bi1/2TiO3 ceramics
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DOI：
10.1063/1.5025275
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发表时间：
2018-04-30
影响因子：
4
通讯作者：
Sinclair, Derek C.
中科院分区：
文献类型：
--
作者：
Li, Linhao;Li, Ming;Sinclair, Derek C.
固溶体（KxNa0.50-x）Bi0.50TiO3（KNBT）由于具有较高的居里温度和良好的压电性能，特别是在x = 0.10（20 mol. % KBT）。在这里，我们表明，低水平的过量K2 O的起始组合物，即，(Ky+0.03Na0.50-y）Bi0.50TiO3.015（y系列），与名义化学计量的KNBT系列（KxNa0.50-x）Bi0.50TiO3（x系列）相比，可以显著改变导电机制和电性能。阻抗谱测量显示y >= 0.10的样品的体电导率（sigma（B））值显著更高[活化能（E-a）]。
The solid solution (KxNa0.50-x)Bi0.50TiO3 (KNBT) between Na1/2Bi1/2TiO3 and K1/2Bi1/2TiO3 (KBT) has been extensively researched as a candidate lead-free piezoelectric material because of its relatively high Curie temperature and good piezoelectric properties, especially near the morphotropic phase boundary (MPB) at x similar to 0.10 (20 mol. % KBT). Here, we show that low levels of excess K2O in the starting compositions, i.e., (Ky+0.03Na0.50-y)Bi0.50TiO3.015 (y-series), can significantly change the conduction mechanism and electrical properties compared to a nominally stoichiometric KNBT series (KxNa0.50-x)Bi0.50TiO3 (x-series). Impedance spectroscopy measurements reveal significantly higher bulk conductivity (sigma(b)) values for y >= 0.10 samples [activation energy (E-a)