Sum-rules for electron energy-loss near-edge spectra

TL;DR

This paper derives four sum-rule expressions for electron energy-loss near-edge spectra, enabling quantitative determination of magnetic moments and electronic properties, validated through experiments on Fe, Co, and Ni crystals.

Contribution

The paper introduces new sum-rules for electron energy-loss spectra based on dynamical diffraction theory, allowing accurate magnetic moment measurements.

Findings

Sum-rules accurately reproduce spin and orbital moments.

Validated on Fe, Co, and Ni crystals.

Provides foundation for quantitative magnetic property analysis.

Abstract

We derive four sum-rule expressions for spectra measured in electron energy-loss near edge structure experiments. These sum-rules permit the determination spin and orbital magnetic moments, spin-orbit interaction and number of states, analogously to the sum rules of x-ray magnetic circular dichroism. The derivation of the sum-rules is based on dynamical electron diffraction theory and the properties of the mixed dynamic form-factor. The accuracy of the sum-rules is tested by a complete evaluation of the thickness dependent electron energy-loss spectra for iron, cobalt, and nickel crystals. We find that the sum-rules reproduce both spin and orbital moments with very good accuracy. Our results provide a foundation for the use of the energy loss magnetic chiral dichroism technique as a quantitative probe of element specific magnetic properties.