Roh Chang Jae, Hamh Sun Young, Woo Chang-Soo, Kim Kwang-Eun, Yang Chan-Ho, Lee Jong Seok
Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Korea.
Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Korea.
Nanoscale Res Lett. 2017 Dec;12(1):353. doi: 10.1186/s11671-017-2126-5. Epub 2017 May 15.
We investigate the ferroelectric state of a tetragonal BiFeO thin film grown on a LaAlO (001) substrate using an optical second harmonic generation (SHG) microscope. Whereas the ferroelectric state of this material hosts nanometer-sized domains which again form micrometer-sized domains of four different configurations, we could figure out the characteristic features of each domain from the SHG mapping with various sizes of the probe beam, i.e., from 0.7 to 3.9 μm in its diameter. In particular, we demonstrate that a single micrometer-sized domain contributes to the SHG as a coherent summation of the constituent nanometer-sized domains, and multi-micrometer-sized domains contribute to the SHG as an incoherent summation of each micro-domain.
我们使用光学二次谐波产生（SHG）显微镜研究了生长在LaAlO（001）衬底上的四方相BiFeO薄膜的铁电态。这种材料的铁电态包含纳米尺寸的畴，这些畴又形成了四种不同构型的微米尺寸的畴，我们能够通过使用不同尺寸探测光束（即直径从0.7到3.9μm）的SHG映射来找出每个畴的特征。特别地，我们证明单个微米尺寸的畴作为组成纳米尺寸畴的相干叠加对SHG有贡献，而多个微米尺寸的畴作为每个微畴的非相干叠加对SHG有贡献。
