论文标题
中心对称HFO2的单个孪晶胶体纳米晶中的多个极化顺序
Multiple polarization orders in individual twinned colloidal nanocrystals of centrosymmetric HfO2
论文作者
论文摘要
自发极化对于非中心对称晶体中的铁电功能至关重要。高融合密度的铁电器需要在小体积中稳定铁电偏振。在这里，原子分辨率透射电子显微镜成像表明，中央粒对称HFO2的胶体纳米晶体中孪晶诱导的对称性断裂会导致形成多个极化顺序，这些极化顺序与亚纳米表铁电离和抗皮质电离相关。发现铁电相的最小尺寸极限为〜4 nm3。密度功能理论的计算表明，铁电和抗抗铁电相之间的转化可以通过晶格应变调节，并且在任何方向上都可以在能量上进行能量。这项工作的结果为HFO2纳米晶体在信息存储中的应用提供了一条途径，其密度比纳米晶体大小所定义的缩放限量高的数量级。
Spontaneous polarization is essential for ferroelectric functionality in non-centrosymmetric crystals. High-integration-density ferroelectric devices require the stabilization of ferroelectric polarization in small volumes. Here, atomic-resolution transmission electron microscopy imaging reveals that twinning-induced symmetry breaking in colloidal nanocrystals of centrosymmetric HfO2 leads to the formation of multiple polarization orders, which are associated with sub-nanometer ferroelectric and antiferroelectric phases. The minimum size limit of the ferroelectric phase is found to be ~4 nm3. Density functional theory calculations indicate that transformations between the ferroelectric and antiferroelectric phases can be modulated by lattice strain and are energetically possible in either direction. The results of this work provide a route towards applications of HfO2 nanocrystals in information storage at densities that are more than an order of magnitude higher than the scaling limit defined by the nanocrystal size.
