Enabling atomic resolution in convergent beam EMCD measurements by the use of patterned apertures

TL;DR

This paper demonstrates high-resolution electron magnetic circular dichroism (EMCD) measurements using innovative patterned apertures, enabling atomic resolution with simplified procedures and verified through experimental results across various convergence angles.

Contribution

The study introduces a new aperture design and experimental approach that simplifies atomic resolution EMCD measurements in convergent beam electron microscopy.

Findings

High-quality EMCD signals achieved at atomic resolution convergence angles.

Experimental validation of ventilator apertures for zone axis EMCD measurements.

Feasibility demonstrated for multiple diffraction symmetries.

Abstract

We give an experimental demonstration of two types of recently proposed ventilator apertures which can be used to acquire electron magnetic circular dichroic (EMCD) signals in zone axis orientation with high spatial resolution. To simplify the experimental procedures, we propose a third type of aperture and experimentally demonstrate the use of this modified ventilator aperture for the case of multiple symmetries in the diffraction patterns. To show the feasibility of the atomic resolution EMCD, EMCD signals are acquired for a range of beam convergence angles. High quality EMCD signals with convergence angles corresponding to atomic resolution electron probes are obtained.