Direct observation of magnetic contrast obtained by photoemission electron microscopy with deep ultra-violet laser excitation

Y C Zhao; H C Lyu; G Yang; B W Dong; J Qi; J Y Zhang; Z Z Zhu; Y Sun; G H Yu; Y Jiang; H X Wei; J Wang; J Lu; Z H Wang; J W Cai; B G Shen; W S Zhan; F Yang; S J Zhang; S G Wang

doi:10.1016/j.ultramic.2019.04.009

Direct observation of magnetic contrast obtained by photoemission electron microscopy with deep ultra-violet laser excitation

Ultramicroscopy. 2019 Jul:202:156-162. doi: 10.1016/j.ultramic.2019.04.009. Epub 2019 Apr 18.

Authors

Y C Zhao¹, H C Lyu², G Yang², B W Dong², J Qi³, J Y Zhang³, Z Z Zhu⁴, Y Sun⁴, G H Yu³, Y Jiang³, H X Wei⁴, J Wang⁴, J Lu⁴, Z H Wang⁴, J W Cai⁴, B G Shen⁴, W S Zhan⁴, F Yang⁵, S J Zhang⁵, S G Wang⁶

Affiliations

¹ State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
² State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China.
³ Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China.
⁴ State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
⁵ Key Lab of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
⁶ State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China. Electronic address: sgwang@ustb.edu.cn.

PMID: 31063898
DOI: 10.1016/j.ultramic.2019.04.009

Abstract

Magnetic circular dichroism (MCD) and magnetic linear dichroism (MLD) have been investigated in a photoemission electron microscopy (PEEM) system excited by a deep ultra-violet (DUV) laser (with λ = 177.3 nm and hυ = 7.0 eV) for the first time. High resolution PEEM magnetic images (down to 43.2 nm) were directly obtained on a (001)-oriented magnetic FePt film surface with a circularly-polarized light under normal incidence. Furthermore, a stepped Cr seeding layer was applied to induce the formation of large-area epitaxial FePt films with (001) and (111) two orientations, where MLD with large asymmetry was observed in the transition area of two phases. It demonstrates that DUV laser can be a powerful source for high resolution magnetic imaging in the laboratory in absence of synchrotron facilities.

Keywords: Deep ultraviolet laser; Magnetic domain imaging; Photoemission electron microscopy.