In this article, we report the development of a new 200-kV analytical electron microscope equipped with a monochromator with an integrated double Wien-filter system. It enables us to study the electronic structures of materials in detail using electron energy-loss spectroscopy (EELS) analysis at an atomic scale. A highly monochromated and isotropically round electron probe is produced on the specimen plane. The ultimate energy resolutions with 0.1-s acquisition times are measured to be 36 meV at 200 kV and 30 meV at 60 kV. In an EELS mapping experiment performed on SrTiO3 with a monochromated electron probe whose energy resolution is 146 meV, an elemental map exhibits atomic resolution.
Keywords: Wien filter; aberration corrector; atomic-resolution EELS mapping; high-resolution EELS; high-resolution STEM; monochromator.
© The Author 2015. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.