Chemically selective modification of spin polarization in ultrathin ferromagnetic films: Microscopic theory and macroscopic experiment

Abstract

Modulation of thin-film magnetic properties will be key to the design of future magnetoelectronic (spintronic) devices. Here, we report the influence of atomic adsorbates upon ultrathin cobalt films on copper, employing secondary electron spin polarization as an incisive experimental probe. We observe that nitrogen suppresses measured polarization by $\ensuremath{\sim}20%$ for the thickest layers; oxygen has little impact in this regime. Moreover, we develop a model capable of predicting these effects, forging a crucial link between microscopic theory and an observable macroscopic magnetic phenomenon.