论文标题
用定量的高光谱相干衍射成像光谱映射纳米级电荷状态和相域
Mapping nanoscale charge states and phase domains with quantitative hyperspectral coherent diffractive imaging spectroscopy
论文作者
论文摘要
功能材料和纳米级设备的临界特性通常源自不同热力学相和 /或氧化态的共存，但是很少完全知道样品构成。连贯的衍射成像（CDI）提供了观察纳米级共存所需的空间分辨率，同时返回对象的完整振幅和相位信息，但迄今为止缺乏组成识别所需的光谱信息。在这里，我们展示了CDI光谱法（CDI），以纳米尺度分辨率获得了跨L2,3的原型量子材料氧化钒的图像和氧气K X射线吸收边缘的图像。使用高光谱X射线图像，我们在单个样品中显示了多个氧化态和相的共存，并提取V2O5的完整复合物折射率以及VO2的单斜膜绝缘和金红石导电阶段。这些结果限制了隐藏阶段在VO2中绝缘体到金属过渡中的作用。
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.
