The Role Of S Passivation On Magnetic Properties Of Fe Overlayers Grown On Gaas(100)

We have produced epitaxial Fe overlayers on sulfur-passivated GaAs(100) surfaces by CH3CSNH2 treatment, and investigated the correlation between magnetic properties of the overlayers and surface chemical structure of GaAs(100) surfaces by ferromagnetic resonance and synchrotron radiation photoemission. The surface chemical properties were modified by changing the annealing temperature of the surfaces prior to the growth. The results show that the magnetization of Fe overlayers is crucially determined by the presence of Ga-S chemical bonds and excess As after the anneals. A comparative investigation of the magnetization has been made on both S passivated and clean GaAs(100). It is confirmed that S passivation on the GaAs surface can effectively eliminate the magnetization deficiency previously attributed to interdiffusion of As into the Fe overlayer. (C) 1999 American Institute of Physics. [S0021-8979(99)06913-3].