Spin Polarized Electron Spectroscopies of 3d and 4f Systems

Abstract

AbstractRecent results from spin polarized electron spectroscopie studies of surfaces and ultrathin films are presented. The Magnetic coupling of 3d transition Metals (Cr,Mn) to the Fe (100) surface is studied by spin polarized electron energy loss spectroscopy. The first atomic layer of Cr and mn aligns antiparallel to the Fe. For larger thicknesses we find evidence for layer-by-layer antiferromagnetic order. In the range of 1–6 atomic layers the behavior is more complex with the surface of the Cr films showing preferential ferromagnetic alignment while the mn surface aligns antiparallel to the Fe substrate.Secondary electrons from Gd (0001) surfaces are shown to be highly spin polarized. However, no enhancement mechanism at low kinetic energy as in the 3d transition metals is observed indicating the absence of strongly spin dependent inelastic scattering in Gd. Temperature dependent spin polarized 4f photoemis-sion results show almost complete polarization demonstrating ferromagnetic surface coupling. However, a perpendicular surface magnetization component is found indicating surface spin canting. A large enhancement of the surface Curie temperature is also present.