Mapping nanoscale charge states and phase domains with quantitative hyperspectral coherent diffractive imaging spectroscopy
Allan S. Johnson, Jordi Valls Conesa, Luciana Vidas, Daniel Perez-Salinas, Christian M. Günther, Bastian Pfau, Kent A. Hallman, Richard F. Haglund, Stefan Eisebitt, Simon Wall
功能材料和纳米器件的关键性能通常源于不同热力学相和/或氧化态的共存，但样品组成很少完全已知的先验。相干衍射成像（CDI）提供了观察纳米尺度共存所需的空间分辨率，同时返回物体的全部振幅和相位信息，但迄今为止缺乏成分识别所需的光谱信息。在这里，我们展示了CDI光谱（CDIS），获得了原型量子材料钒氧化物的图像，跨越钒L2，3和氧K X射线吸收边，具有纳米级分辨率。使用高光谱X射线图像，我们显示在一个单一的样品中的多个氧化状态和阶段的共存，并提取完整的复折射率的V2 O 5和单斜绝缘和金红石导电相的VO 2。这些结果限制了隐藏相在VO 2绝缘体到金属过渡中的作用。
英文摘要：
The critical properties of functional materials and nanoscale devices often originate from the coexistence of different thermodynamic phases and / or oxidization states, but sample makeup is seldom completely known a priori. Coherent diffractive imaging (CDI) provides the spatial resolution needed to observe nanoscale coexistence while returning the full amplitude and phase information of an object, but to date lacks the spectral information necessary for composition identification. Here we demonstrate CDI spectroscopy (CDIS), acquiring images of the prototypical quantum material vanadium oxide across the vanadium L2,3 and oxygen K X-ray absorption edges with nanometer scale resolution. Using the hyperspectral X-ray image we show coexistence of multiple oxidization states and phases in a single sample and extract the full complex refractive index of V2O5 and the monoclinic insulating and rutile conducting phases of VO2. These results constrain the role of hidden phases in the insulator-to-metal transition in VO2.
Swinburne University of Technology（斯威本科技大学）；Australian Research Council (ARC) Industrial Transformation Training Centre in Surface Engineering for Advanced Materials (SEAM)（澳大利亚研究理事会先进材料表面工程工业转型培训中心）；Melbourne Centre for Nanofabrication（墨尔本纳米制造中心）；Institute of Science Tokyo（东京科学大学研究所）；Yokohama National University（横滨国立大学）；JST（日本科学技术振兴机构）；Indian Institute of Technology Hyderabad（印度理工学院海得拉巴分校）；Attocube Systems AG（阿托库贝系统股份公司）；ANSTO‒Australian Synchrotron（澳大利亚核科学与技术组织-澳大利亚同步辐射加速器）；Center for Physical Sciences and Technology（物理与化学科学研究中心）
Laser-induced transient opacity in helium nanodroplets probed by single-shot coherent diffraction
ETH Zurich（苏黎世联邦理工学院）；University of Rostock（罗斯托克大学）；Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy（马克斯·玻恩非线性光学和超快光谱研究所）；Technical University of Berlin（柏林工业大学）
