ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology , Castelldefels , 08860 Barcelona , Spain.
Institut für Optik und Atomare Physik , Technische Universität Berlin , 10623 Berlin , Germany.
Nano Lett. 2018 Jun 13;18(6):3449-3453. doi: 10.1021/acs.nanolett.8b00458. Epub 2018 May 18.
We use resonant soft X-ray holography to image the insulator-metal phase transition in vanadium dioxide with element and polarization specificity and nanometer spatial resolution. We observe that nanoscale inhomogeneity in the film results in spatial-dependent transition pathways between the insulating and metallic states. Additional nanoscale phases form in the vicinity of defects which are not apparent in the initial or final states of the system, which would be missed in area-integrated X-ray absorption measurements. These intermediate phases are vital to understand the phase transition in VO, and our results demonstrate how resonant imaging can be used to understand the electronic properties of phase-separated correlated materials obtained by X-ray absorption.
我们使用共振软 X 射线全息术，以元素和极化特异性以及纳米空间分辨率对二氧化钒中的绝缘-金属相变进行成像。我们观察到，薄膜中的纳米级不均匀性导致了在绝缘态和金属态之间的空间相关的转变途径。在系统的初始或最终状态中不明显的缺陷附近会形成额外的纳米级相，这在面内积分 X 射线吸收测量中会被忽略。这些中间相对于理解 VO 的相变至关重要，我们的结果表明共振成像如何用于理解通过 X 射线吸收获得的分相相关材料的电子性质。
