Kelley Kyle P, Sharma Vinit, Zhang Wenrui, Baddorf Arthur P, Nascimento Von B, Vasudevan Rama K
Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.
National Institute for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.
ACS Appl Mater Interfaces. 2021 Feb 24;13(7):9166-9173. doi: 10.1021/acsami.0c20166. Epub 2021 Feb 10.
Due to an extremely diverse phase space, LaSrMnO, as with other manganites, offers a wide range of tunability and applications including colossal magnetoresistance and use as spin-polarized electrodes. Here, we study an unprecedented, exotic surface reconstruction (6 × 6) in LaSrMnO ( = 0.3) observed via low-energy electron diffraction (LEED). Scanning tunneling microscopy (STM) shows the surface is relatively flat, with unit-cell step heights, and X-ray photoelectron spectroscopy (XPS) reveals a strong degree of Sr segregation at the surface. By combining electron diffraction and first-principles computations, we propose that the long-range surface reconstruction consists of a Sr-segregated surface with La (6 × 6) ordering. This study expands our understanding of manganite systems and underscores their ability to form interesting surface reconstructions, driven largely by cation segregation that can potentially be controlled for tuning surface ordering.
由于具有极其多样的相空间，与其他锰氧化物一样，LaSrMnO具有广泛的可调性和应用，包括巨磁电阻以及用作自旋极化电极。在此，我们研究了通过低能电子衍射（LEED）在LaSrMnO（= 0.3）中观察到的前所未有的奇特表面重构（6×6）。扫描隧道显微镜（STM）显示表面相对平坦，具有晶胞台阶高度，而X射线光电子能谱（XPS）揭示了表面存在强烈的Sr偏析。通过结合电子衍射和第一性原理计算，我们提出长程表面重构由具有La（6×6）有序排列的Sr偏析表面组成。这项研究扩展了我们对锰氧化物体系的理解，并强调了它们形成有趣表面重构的能力，这在很大程度上是由阳离子偏析驱动的，而阳离子偏析可能可以通过控制来调节表面有序性。
