Determination of fast electron energy dependence of magic angles in electron energy loss spectroscopy for anisotropic systems

TL;DR

This paper accurately determines the magic angle conditions in electron energy loss spectroscopy for anisotropic materials, revealing the role of quantum interference effects and enabling improved material characterization techniques.

Contribution

It introduces a precise method to identify magic angles in EELS for anisotropic systems and highlights the significance of quantum interference effects at medium electron energies.

Findings

Magic angles eliminate sample-orientation effects in EELS.

Quantum interference between interactions affects anisotropic EELS.

Method enhances material characterization accuracy.

Abstract

We present an accurate determination of the magic angle conditions at which the sample-orientation induced fine structure variation is eliminated in the core-level electron energy loss spectroscopy of anisotropic systems. Our result paves the way for the application of magic angle electron energy loss spectroscopy (MAEELS) in material characterization. It also highlights, for the first time, the importance of the quantum interference effect between longitudinal and transverse interactions for medium energy fast electrons, and its connection with the anisotropy of the electron transition.