Soft X-ray ARPES for three-dimensional crystals in the micrometre region

Takayuki Muro; Yasunori Senba; Haruhiko Ohashi; Takuo Ohkochi; Tomohiro Matsushita; Toyohiko Kinoshita; Shik Shin

doi:10.1107/S1600577521007487

Soft X-ray ARPES for three-dimensional crystals in the micrometre region

J Synchrotron Radiat. 2021 Sep 1;28(Pt 5):1631-1638. doi: 10.1107/S1600577521007487. Epub 2021 Aug 16.

Authors

Takayuki Muro¹, Yasunori Senba¹, Haruhiko Ohashi¹, Takuo Ohkochi¹, Tomohiro Matsushita¹, Toyohiko Kinoshita¹, Shik Shin²

Affiliations

¹ Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan.
² The Institute for Solid State Physics (ISSP), The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan.

PMID: 34475310
DOI: 10.1107/S1600577521007487

Abstract

An endstation dedicated to angle-resolved photoemission spectroscopy (ARPES) using a soft X-ray microbeam has been developed at the beamline BL25SU of SPring-8. To obtain a high photoemission intensity, this endstation is optimized for measurements under the condition of grazing beam incidence to a sample surface, where the glancing angle is 5° or smaller. A Wolter mirror is used for focusing the soft X-rays. Even at the glancing angle of 5°, the smallest beam spot still having a sufficient photon flux for ARPES is almost round on the sample surface and the FWHM diameter is ∼5 µm. There is no need to change the sample orientation for performing k_x - k_y mapping by virtue of the electron lens with a deflector of the photoelectron analyzer, which makes it possible to keep the irradiation area unchanged. A partially cleaved surface area as small as ∼20 µm was made on an Si(111) wafer and ARPES measurements were performed. The results are presented.

Keywords: BL25SU; SPring-8; microbeams; soft X-ray ARPES.