Uses of Spin-polarised Electrons in Fundamental Electron-Atom Collision Processes and the Analysis of Magnetic Microstructures

Abstract

Two experimental programs are discussed which exploit the use of polarised electrons for studies of fundamental processes and physical properties. In one program, collisions between spin·polarised electrons and optically pumped sodium atoms provide a very detailed characterisation of the spin-dependent interactions important in low-energy electron-atom collisions. The results of these measurements provide a critical test for the reliability of state-of-the·art electron scattering calculations. In the second program, the spin polarisation of secondary electrons ejected by high· energy electron impact is used to determine the magnetic structure of ferromagnetic materials with very high spatial resolution (-60 nm). This ability to perform such studies with high resolution has been exploited both in studies of the basic magnetic properties of ferromagnetic materials and in studies of how these basic properties affect the magnetic structure and performance of devices used for magnetic information storage.