Quantitative magnetic information from reciprocal space maps in transmission electron microscopy

One of the most challenging issues in the characterization of magnetic materials is to obtain quantitative analysis on the nanometer scale. Here we describe how electron magnetic circular dichroism (EMCD) measurements using the transmission electron microscope (TEM) can be used for that purpose, utilizing reciprocal space maps. Applying the EMCD sum rules, an orbital to spin moment ratio of $m_L/m_S=0.08 \pm 0.01$ is obtained for Fe, which is consistent with the commonly accepted value. Hence, we establish EMCD as a quantitative element specific technique for magnetic studies, using a widely available instrument with superior spatial resolution.