Quantitative X-ray Schlieren Nanotomography for Hyperspectral Phase and Absorption Imaging

Abstract: Hyperspectral X-rays imaging holds promise for three-dimensional (3D) chemical analysis but remains limited in simultaneously capturing phase and absorption information due to complex setups and data burdens. We introduce quantitative X-ray schlieren nanotomography (XSN), a simple, fast, and high-resolution X-ray phase imaging technique that overcomes these limitations. XSN employs a partially coherent illumination and a pupil-plane cutoff filter to encode directional phase contrast, enabling single-shot acquisition. A quasi-Newton iterative algorithm reconstructs quantitative phase and absorption images from intensity data, even under strong scattering conditions. Scanning across X-ray energies further allows four-dimensional imaging (3D spatial & spectral). We validate the method's accuracy and resolution on reference samples and apply it to lithium battery cathodes, visualizing nanoscale microcracks and mapping chemical compositions. XSN provides a robust framework for hyperspectral phase nanotomography with broad applicability across materials science, biology, and energy research.