Atomic resolution electron microscopy in a magnetic field free environment

N Shibata,S D Findlay,S Morishita,H Sawada,A Nakamura,T Seki,T Matsumoto,Y Ikuhara,Y Kohno,A Kumamoto

doi:10.1038/s41467-019-10281-2

Abstract

Atomic-resolution electron microscopes utilize high-power magnetic lenses to produce magnified images of the atomic details of matter. Doing so involves placing samples inside the magnetic objective lens, where magnetic fields of up to a few tesla are always exerted. This can largely alter, or even destroy, the magnetic and physical structures of interest. Here, we describe a newly developed magnetic objective lens system that realizes a magnetic field free environment at the sample position. Combined with a higher-order aberration corrector, we achieve direct, atom-resolved imaging with sub-Å spatial resolution with a residual magnetic field of less than 0.2 mT at the sample position. This capability enables direct atom-resolved imaging of magnetic materials such as silicon steels. Removing the need to subject samples to high magnetic field environments enables a new stage in atomic resolution electron microscopy that realizes direct, atomic-level observation of samples without unwanted high magnetic field effects.

Highlights

Atomic-resolution electron microscopes utilize high-power magnetic lenses to produce magnified images of the atomic details of matter
The spatial resolution of transmission electron microscope (TEM) has been strongly limited not by the wavelength of the incident electrons but rather by the performance of the magnetic objective lens: it forms the primary image and diffraction pattern, which will be magnified by all the other lenses, and so the quality of the final image is severely affected by its lens aberrations
We develop a new magnetic objective lens system combined with a state-of-the-art aberration corrector and thereby simultaneously realize atomic resolution electron microscopy and a magnetic field-free sample environment

Summary

Introduction

Atomic-resolution electron microscopes utilize high-power magnetic lenses to produce magnified images of the atomic details of matter. We develop a new magnetic objective lens system combined with a state-of-the-art aberration corrector and thereby simultaneously realize atomic resolution electron microscopy (with sub-Å spatial resolution) and a magnetic field-free sample environment.

Results

Conclusion