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Energy-loss magnetic chiral dichroism (EMCD): Magnetic chiral dichroism in the electron microscope

Published online by Cambridge University Press:  31 January 2011

S. Rubino ,
P. Schattschneider ,
M. Stöger-Pollach ,
C. Hébert ,
J. Rusz ,
L. Calmels ,
B. Warot-Fonrose ,
F. Houdellier ,
V. Serin  and
P. Novak
S. Rubino
Affiliation:
Institute for Solid State Physics, Vienna University of Technology, Vienna A-1040, Austria; and Department of Engineering, Uppsala University, Uppsala S-751 21, Sweden
P. Schattschneider
Affiliation:
Institute for Solid State Physics, Vienna University of Technology, Vienna A-1040, Austria; and Service Centre for TEM, Vienna University of Technology, Vienna A-1040, Austria
M. Stöger-Pollach
Affiliation:
Service Centre for TEM, Vienna University of Technology, Vienna A-1040, Austria
C. Hébert
Affiliation:
SB-CIME Station 12, EPFL, Lausanne, Switzerland
J. Rusz
Affiliation:
Department of Physics, Uppsala University, Uppsala S-751 21, Sweden; and Institute of Physics, Academy of Sciences of the Czech Republic, Prague CZ-18221, Czech Republic
L. Calmels
Affiliation:
Nanomaterieaux Group, CEMES-CNRS, FR-31400 Toulouse, France
B. Warot-Fonrose
Affiliation:
Nanomaterieaux Group, CEMES-CNRS, FR-31400 Toulouse, France
F. Houdellier
Affiliation:
Nanomaterieaux Group, CEMES-CNRS, FR-31400 Toulouse, France
V. Serin
Affiliation:
Nanomaterieaux Group, CEMES-CNRS, FR-31400 Toulouse, France
P. Novak
Affiliation:
Institute of Physics, Academy of Sciences of the Czech Republic, Prague CZ-18221, Czech Republic
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Abstract

A new technique called energy-loss magnetic chiral dichroism (EMCD) has recently been developed [P. Schattschneider, et al. Nature441, 486 (2006)] to measure magnetic circular dichroism in the transmission electron microscope (TEM) with a spatial resolution of 10 nm. This novel technique is the TEM counterpart of x-ray magnetic circular dichroism, which is widely used for the characterization of magnetic materials with synchrotron radiation. In this paper we describe several experimental methods that can be used to measure the EMCD signal [P. Schattschneider, et al. Nature441, 486 (2006); C. Hébert, et al. Ultramicroscopy108(3), 277 (2008); B. Warot-Fonrose, et al. Ultramicroscopy108(5), 393 (2008); L. Calmels, et al. Phys. Rev. B76, 060409 (2007); P. van Aken, et al. Microsc. Microanal.13(3), 426 (2007)] and give a review of the recent improvements of this new investigation tool. The dependence of the EMCD on several experimental conditions (such as thickness, relative orientation of beam and sample, collection and convergence angle) is investigated in the transition metals iron, cobalt, and nickel. Different scattering geometries are illustrated; their advantages and disadvantages are detailed, together with current limitations. The next realistic perspectives of this technique consist of measuring atomic specific magnetic moments, using suitable spin and orbital sum rules, [L. Calmels, et al. Phys. Rev. B76, 060409 (2007); J. Rusz, et al. Phys. Rev. B76, 060408 (2007)] with a resolution down to 2 to 3 nm.

Keywords

Electron energy loss spectroscopy (EELS)Magnetic propertiesTransmission electron microscopy (TEM)
Type
Outstanding Symposium Papers
Information
Journal of Materials Research , Volume 23 , Issue 10 , October 2008 , pp. 2582 - 2590
Copyright
Copyright © Materials Research Society 2008

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