In this method, a series of 2D imaging of a sample at a series of energy points near the absorption edge of an element is performed. After alignment, normalization, PCA analysis, and reference spectrum fitting of these 2D images (image stack), the quantitative spatial distribution of the chemical states of the element and the corresponding absorption spectra can be obtained.

Biotransformation of cerium nanoparticles in cellular tissues. Stack imaging revealed that the chemical composition of the needle-like nanoclusters was cerium phosphate, confirming the transformation of cerium dioxide nanoparticles. This is the first time that cerium dioxide nanoclusters have been found and demonstrated to be able to be transformed in biological systems, providing important information for the evaluation of the ecotoxicology of cerium dioxide nanoclusters. [ACS Nano 2012, 6, 9943]

After the X-photon strikes out the inner-shell electron, a valence orbital electron returns to the inner-shell cavity, and the released energy excites another valence electron to the free state, generating ohmic or secondary electrons with yields as high as 99 percent.

XMCD principle schematic

BL08U1A is the first to realize the measurement of orbital effects of electrically regulated electrons, revealing new mechanisms of electrically regulated magnetic effects based on orbital reconfiguration. [Progress in Materials Science 2017, 87, 33]

By replacing the detector of STXM with a CCD and scanning the samples with overlapping, combined with an iterative phase retrieval reconstruction algorithm, the high-resolution ptychography imaging can be realized with a resolution of 5-10 nm. BL08U1A endstation has successfully established this experimental method, which improves the spatial resolving capability of the Shanghai Light Source from 30 nm to 8 nm, and reduces the imaging dose to 1/12 that of the conventional STXM technology. The comprehensive performance of our ptychography platform is among the best ones in the world. [J. Phys. Conf. Ser. 2017, 849, 012033]

 

This beamline combines chemical element identification and 3D structural imaging of samples to realize characterization of sample 3D structures and element 3D distribution at nanoscale.

3D nano-imaging of an adherent immune cell (left) and 3D distribution of intracellular Gd elements (right).

　　Schematic diagram of fluorescence yield absorption spectroscopy

　　Soft X-ray fluorescence absorption spectra are collected in PFY mode. The PFY measurement system consists of an SDD, a data acquisition electronics device (PX5), an in-vacuum adjustable stand, vacuum leads, and vacuum connection flanges. The internal configuration of the chamber is shown in the right figure, with the incident soft X-rays at an angle of about 45 degree to the sample. The sample is also at about 45 degree to the SDD probe.

　　

　　Reactivity regulation of lithium-rich oxide cathode materials

Lithium-rich manganese-based layer-like oxide cathode materials have attracted much attention due to advantages such as high specific capacity. In this study, a three-in-one lithium-rich oxide material modification strategy is proposed, which integrates LiSnO3 capping, Sn doping and spinel heterostructure. This strategy can significantly improve the oxygen ion redox activity and reversibility and reduce the irreversible release of oxygen. Meanwhile, the Coulombic efficiency, specific capacity, multiplicity characteristics and cyclability are all greatly improved. The O-K edge XAS in fluorescence mode demonstrated that the materials containing oxygen vacancies and spinel structure enhanced the reversibility of anion redox. This study is an important guide for improving the electrochemical performance of anode materials。[Adv. Funct. Mater. 2019, 1806706]

2D XEOL-TEY spectral image

The PLY and TEY spectra of nano-ZnO at O K-edge

Adjusting the polarization direction of the X-rays, scanning transmission imaging of the sample with right and left circularly polarized light, respectively, and subtracting the two images, the magnetic domain microscopic image is thus obtained.

(A-C) STXM micrographs of circular, square, and triangular magnetic microstructures, respectively, and the scale of each figure is 2 um; (D-F) are the magnetic domain distributions in the three structures simulated by micromagnetism. The red dots in (G-H) denote the horizontal magnetization intensities (HMI) of the points on the red circles in (A-C); and blue dots denote the HMIs of the corresponding positions in (D-F). [Acta Physica Sinica 64, 197502 (2015)]

Comparison of magnetic domain imaging by ptychography (left and middle) with that by STXM (right), showing that ptychography further improves the resolution of magnetic domain imaging.

The self-constructed new STXM endstation has successfully realized high-resolution (30nm) imaging, and the scanning imaging efficiency has been improved by ten times compared with the old endstation through the bidirectional scanning technology and FPGA timing control scheme. [J. Synchrotron Rad. 2021, 28, 512]

New STXM chamber appearance, internal structure and control interface

New STXM star pattern imaging (30nm innermost stripe) and large field of view imaging of cancerous tissue (86um x 76um, 25nm step)