Chen Pice, Cosgriff Margaret P, Zhang Qingteng, Callori Sara J, Adams Bernhard W, Dufresne Eric M, Dawber Matthew, Evans Paul G
Department of Materials Science and Engineering & Materials Science Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA.
Phys Rev Lett. 2013 Jan 25;110(4):047601. doi: 10.1103/PhysRevLett.110.047601. Epub 2013 Jan 24.
The remnant polarization of weakly coupled ferroelectric-dielectric superlattices is distributed unequally between the component layers, and as a result the components respond differently to applied electric fields. The difference is apparent in both the nanometer-scale structure of striped polarization domains and in the development of piezoelectric strain and field-induced polarization. Both effects are probed with in situ time-resolved synchrotron x-ray diffraction in a PbTiO(3)/SrTiO(3) superlattice in fields up to 2.38 MV/cm. Domains are initially distorted to increase the polarization in the SrTiO(3) layer while retaining the striped motif. The subsequent transformation to a uniform polarization state at a later time leads to piezoelectric expansion dominated by the field-induced polarization of the SrTiO(3) layers. The results are consistent with theoretical predictions of the field dependence of the domain structure and electrical polarization.
弱耦合铁电-介电超晶格的剩余极化在组成层之间分布不均，因此各组分对施加电场的响应不同。这种差异在条纹极化畴的纳米级结构以及压电应变和场致极化的发展中都很明显。在高达2.38 MV/cm的电场中，利用原位时间分辨同步加速器X射线衍射对PbTiO(3)/SrTiO(3)超晶格中的这两种效应进行了探测。畴最初发生畸变，以增加SrTiO(3)层中的极化，同时保留条纹图案。随后在稍后时间转变为均匀极化状态，导致以SrTiO(3)层的场致极化为主导的压电膨胀。结果与畴结构和电极化的场依赖性的理论预测一致。
