Quantitative magnetic information from reciprocal space maps in transmission electron microscopy

TL;DR

This paper demonstrates how reciprocal space maps in transmission electron microscopy can be used with electron magnetic circular dichroism to quantitatively analyze magnetic properties at the nanometer scale, establishing a new precise measurement technique.

Contribution

The study introduces a method to obtain quantitative magnetic information using EMCD in TEM with reciprocal space maps, validated by a specific orbital to spin moment ratio for iron.

Findings

Quantitative magnetic measurements are achievable with EMCD in TEM.

The orbital to spin moment ratio for Fe was measured as 0.08 ± 0.01.

EMCD is established as a quantitative, element-specific magnetic analysis technique.

Abstract

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.