Spin-polarised low-energy electron diffraction

Abstract

A review is given of elastic spin-polarised low-energy electron diffraction (SPLEED) from crystalline surfaces. For the two relevant spin-dependent interaction mechanisms, spin-orbit coupling, and exchange, dynamical theories are presented with emphasis on symmetry principles, potential models and multiple scattering formalisms. Brief accounts of computational aspects and experimental apparatus (polarised-electron source, spin detectors) are followed by a survey and discussion of experimental and theoretical results for non-magnetic and magnetic surfaces. Finally, the impact of SPLEED on electron emission methods is pointed out, and the prospects of SPLEED as a powerful tool for surface analysis are assessed.

The electron analogue to the Faraday rotation

“…According to equation (3) decreases with E −1/2 , but the observed much steeper decrease of proves that ∆E ex is also reduced when E increases. This is in accordance with theory: the higher the energy, the weaker the exchange interaction between the impinging hot electrons and the electrons below E F [15].…”

The Dynamic Response of Magnetization to Hot Spins

“…Thus, there must also be a strong decrease in exchange energy with increasing energy. This is in accordance with calculations that show a clear decrease in ∆E ex with increasing energy [32]. The higher the energy, the weaker the exchange interaction between the quasi-free injected electrons and the d electrons below the Fermi level.…”

Influence of the scattering potential model on low energy electron diffraction from Cu(001)-c(2 × 2)-Pb

“…[26], and references therein), assuming Debye temperatures Ocu of 330 K for Cu and [~Pb between 50 and 150 K for Pb. The resulting phase shifts are used in a relativistic multiple scattering formalism [27] to calculate spin polarization and intensity versus energy spectra for the optimal geometry of the adsorbate system. Since relativistic LEED calculations require about a factor of seven more computing time than their nonrelativistic counterparts, this geometry is determined by nonrelativistic LEED intensity calculations employing the spin-averaged phase shifts 6;.…”