Migration-induced field-stabilized polar phase in strontium titanate single crystals at room temperature
Migration-induced field-stabilized polar phase in strontium titanate single crystals at room temperature
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DOI：
10.1103/physrevb.88.024104
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发表时间：
2013-07-08
影响因子：
3.7
通讯作者：
Meyer, Dirk C.
中科院分区：
文献类型：
--
作者：
Hanzig, Juliane;Zschornak, Matthias;Meyer, Dirk C.
外加电场作用下SrTiO3单晶的局部可逆结构变化是由氧重分布引起的。我们提出了在电形成过程中和电形成之后的现场x射线衍射测量。对几个反射进行了监测，显示钛酸锶的立方晶胞伸长。拉曼研究证实，单位胞的膨胀涉及从中心对称到低对称相的过渡。在一个完整的形成周期中，包括电场保持时间和无电场松弛时间，观察到从立方对称到四方畸变可逆转变的两种不同的动力学：在场方向上晶格常数增加时的缓慢动力学和在关闭电场后的快速动力学。基于实验数据，我们提出了在室温下由电场稳定的极性钛酸锶单体电池的形成，这被称为迁移诱导的场稳定极性相。
Local reversible structural changes in SrTiO3 single crystals in an external electric field are induced by oxygen redistribution. We present in situ x-ray diffraction measurements during and immediately after electroformation. Several reflections are monitored and show an elongation of the cubic unit cell of strontium titanate. Raman investigations verify that the expansion of the unit cell involves a transition from the centrosymmetric to a lower symmetry phase. During a complete formation cycle, including the hold time of the electric field and relaxation time without field, two different dynamics are observed for the reversible transitions from cubic symmetry to tetragonal distortion: a slow one during the increase of the lattice constant in field direction and a fast one after switching off the electric field. Based on the experimental data, we propose the formation of a polar strontium titanate unit cell at room temperature stabilized by the electric field, which is referred to as migration-induced field-stabilized polar phase.