| Time：1141203 (Wed.) 14:20~16:20 Speaker：Prof.莊子弘/ Chuang, Tzu-Hung 國家同步輻射研究中心奈米科學小組/Nano Science Group, National Synchrotron Radiation Research Center Title：Soft X-ray photoelectron spectro-microscopy at the Taiwan Photon Source Abstract： An imaging-type photoelectron momentum microscope (MM) recently established at the Taiwan Photon Source (TPS) 27A2 [1-2] is an ideal tool for probing advanced two-dimensional (2D) van der Waals (vdW) materials, taking advantages of the combination of direct-space and momentum-space imaging and photoelectron spectroscopy capabilities with both element- and spin-resolution. Offline commissioning of the MM was performed using two in-house ultraviolet (UV) sources [2], and the commissioning with synchrotron soft X-rays has been initiated in mid- 2025. In this talk, the performance of the MM by measuring a standard checkerboard-patterned specimen and an Au(111) single crystal using UV sources will be first presented. By analyzing the intensity profile of the edge of the Au patterns, the Rashba-splitting of Au(111) Shockley surface state at 300 K, and the photoelectron intensity across the Fermi-edge at 80 K, the spatial, momentum, and energy resolution were estimated to be 50 nm, 0.0172 Å-1 and 26 meV, respectively [2]. Finally, synchrotron soft X-rays have been arrived at the 27A2 end-station in mid-2025. Recent commissioning results on imaging-based X-ray photoelectron spectroscopy (XPS), X- ray absorption spectroscopy (XAS), and X-ray magnetic circular dichroism (XMCD) measured on a 2D vdW material and a ferromagnetic thin film, respectively, will be demonstrated. References: [1] Shiu, et. al., “When microscopy meets soft X-ray at TLS and TPS”, J. Electron Spectrosc. Relat. Phenom. 266, 147363 (2023). [2] Chuang, et al., “Performance of a photoelectron momentum microscope in direct- and momentum-space imaging with ultraviolet photon source”, J. Synchrotron Rad. 31, 195 (2024). Place：S101, Gongguan Campus, NTNU |
