電子磁気円二色性によるナノ領域磁気モーメントの測定

抄録

It is demonstrated that the spin/orbital magnetic momenta ratio of a BCC iron nano-polycrystalline film is quantitatively measured using ultra-high voltage scanning transmission electron microscopy and electron energy-loss spectroscopy. In the present article we first introduce electron magnetic circular dichroism (EMCD), electron counterpart of X-ray MCD (XMCD) and discuss its principle, experimental setup and technical difficulties. We then propose a new approach to EMCD measurements, taking advantage of a higher accelerating voltage of the incident electrons, which considerably enhances the outreach of the technique and enables us quantitative magnetic information to be routinely obtained using electron beams of only a few nanometres in diameter without imposing any restriction regarding the crystalline order of the specimen.