What we can learn from magnetic Compton scattering: application to the determination of spin polarization

J A Duffy

doi:10.1088/1742-6596/443/1/012011

Abstract

Studies of spin-resolved electron momentum densities involve the measurement of the so-called magnetic Compton profile. This is a one-dimensional projection of the electron momentum distribution of only those electrons that contribute to the spin moment of a sample. The technique is applicable to ferri- and ferromagnetic materials. The profile is obtained via the inelastic 'Compton' scattering of high energy X-rays. Since electrons originating from different atomic orbitals have specific momentum densities, it is often possible to determine the origin of the magnetism present. Typically, interpretation requires the use of electronic structure calculations using molecular orbital and band structure approaches. Here, we highlight the application of the technique to the determination of the Fermi level spin polarization, the knowledge of which is important to the development of novel spintronic materials.

Highlights

Introduction to magnetic Compton scatteringCompton scattering studies involve the non-resonant inelastic scattering of high energy photons
When the X-rays are inelastically scattered by the electrons in the sample, the scattered photon energy distribution is Doppler broadened because of the electrons’ momentum distribution
If the scattering event is described within the impulse approximation [1, 2], the measured spectrum represents a 1-dimensional projection of the electron momentum distribution, n(p), resolved along the z direction, which is parallel to the scattering vector

Summary

Introduction

Introduction to magnetic Compton scatteringCompton scattering studies involve the non-resonant inelastic scattering of high energy photons. Two specific applications of the technique are the measurements of Fermi surfaces and spin resolved electron momentum densities. Incident photon energies of 90-200keV are normally used, and, for magnetic measurements, a degree of circular polarization is required.

Results

Conclusion