Quantitative characterization of nanoscale polycrystalline magnets with electron magnetic circular dichroism.
Electron magnetic circular dichroism (EMCD) allows the quantitative, element-selective determination of spin and orbital magnetic moments, similar to its well-established X-ray counterpart, X-ray magnetic circular dichroism (XMCD). As an advantage over XMCD, EMCD measurements are made using transmission electron microscopes, which are routinely operated at sub-nanometre resolution, thereby potentially allowing nanometre magnetic characterization. However, because of the low intensity of the EMCD signal, it has not yet been possible to obtain quantitative information from EMCD signals at the nanoscale. Here we demonstrate a new approach to EMCD measurements that considerably enhances the outreach of the technique. The statistical analysis introduced here yields robust quantitative EMCD signals. Moreover, we demonstrate that quantitative magnetic information can be routinely obtained using electron beams of only a few nanometres in diameter without imposing any restriction regarding the crystalline order of the specimen.
Division of Energy Science, EcoTopia Science Institute, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan.
Shunsuke
S
Muto
Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala S-75120, Sweden.
Ján
J
Rusz
Division of Energy Science, EcoTopia Science Institute, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan.
Kazuyoshi
K
Tatsumi
Peter Grünberg Institut, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany.
Roman
R
Adam
Division of Energy Science, EcoTopia Science Institute, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan.
Shigeo
S
Arai
Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala S-75120, Sweden.
Vancho
V
Kocevski
Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala S-75120, Sweden.
Peter M
PM
Oppeneer
Peter Grünberg Institut, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany.
Daniel E
DE
Bürgler
Peter Grünberg Institut, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany.
Claus M
CM
Schneider