KENBIKYO Vol.52▶No.2 2017

Measurements of Magnetic Chiral Dichroism Using Nano-Electron Probe

Shunsuke Muto and Ján Rusz

Abstract: The method for detecting magnetic circular (chiral) dichroic signals using energy-loss spectroscopy of fast electrons running through a sample is called as ‘Energy-loss magnetic chiral dichroism (EMCD) measurement’, which enables us to measure the magnetic moments localized in magnetic elements at nanometer scale. EMCD is a counterpart of X-ray magnetic circular dichroism (XMCD), a difference spectrum of the two X-ray absorption fine structure (XAFS) spectra obtained by clockwise and counterclockwise circularly polarized photons. More than 10 year have passed since Prof. Schattschneider of Vienna Technical University first proposed its idea, and the EMCD measurement scheme has developed as far as the stage where even atomic-plane resolution is feasible after a pile of trials and errors both from theoretical and experimental points of view. In this review we start with the fundamental principle of the measurement scheme and historical development, followed by several application examples mainly achieved by the present authors’ group. Finally we briefly touch the present status and prospects of the field in future.

Key words: ferromagnetism, magnetic moment, magnetic chiral dichroism, electron energy-loss spectroscopy, statistical informatics processing