Effects of poling and crystallinity on the dielectric properties of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 at cryogenic temperatures
Effects of poling and crystallinity on the dielectric properties of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 at cryogenic temperatures
复制标题
低温下极化和结晶度对 Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 介电性能的影响
DOI：
10.1038/s41598-019-38995-9
复制
发表时间：
2019
影响因子：
4.6
通讯作者：
Shepley P
中科院分区：
文献类型：
--
作者：
Shepley P
之前已经将弛豫型PbTiO 3型单晶的超大室温压电活性的机制与压电和介电性质中的低温弛豫联系起来。采用介电常数测量方法研究了Pb（In 1/2Nb 1/2）O3-Pb（Mg 1/3 Nb 2/3）O3-PbTiO 3在10 ~ 300 K之间的介电性质。我们比较了在[001]和[111]方向上测量的单晶片与相同组成的多晶陶瓷的结果。极化的晶体与未极化的晶体具有非常不同的行为，而多晶陶瓷的介电谱在极化时变化很小。在100 K附近，在极化的[001]晶体中观察到大的、频率依赖的介电弛豫。[111]切割晶体中的弛豫不太突出，并且不存在于多晶陶瓷中。在极化的[001]取向晶体中大弛豫的独特存在表明，这种现象不仅仅是由于它们的弛豫性质。我们建议，异相动力学，如相域边界的运动是负责的异常机电和介电行为。
The mechanisms underlying the anomalously large, room temperature piezoelectric activity of relaxor-PbTiO3type single crystals have previously been linked to low temperature relaxations in the piezoelectric and dielectric properties. We investigate the properties of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3between 10 and 300 K using dielectric permittivity measurements. We compare results on single crystal plates measured in the [001] and [111] directions with a polycrystalline ceramic of the same composition. Poled crystals have very different behaviour to unpoled crystals, whereas the dielectric spectrum of the polycrystalline ceramic changes very little on poling. A large, frequency dependent dielectric relaxation is seen in the poled [001] crystal around 100 K. The relaxation is much less prominent in the [111] cut crystal, and is not present in the polycrystalline ceramic. The unique presence of the large relaxation in poled, [001] oriented crystals indicates that the phenomenon is not due their relaxor nature alone. We propose that heterophase dynamics such as the motion of phase domain boundaries are responsible for both the anomalous electromechanical and dielectric behaviour.