The growth of Fe on sulphur passivated Ge(100): A technique for avoiding intermixing

The growth of Fe on Ge(100) surfaces results in the intermixing of Ge with the Fe overlayer, producing relatively thick magnetic dead layers. In this paper we describe a new technique, the growth of Fe overlayers on S-passivated Ge(100), which successfully prevents the intermixing of Ge with the Fe overlayer. Bcc Fe(100) is observed to grow epitaxially on this substrate, with the S floating out as an ordered overlayer. The S prevents intermixing by acting as a surfactant, holding the Fe on top of the substrate and preventing interdiffusion. The Fe overlayers are observed to be ferromagnetic in nature, displaying sharp hysteresis loops with easy axes along the Fe[010] directions. A uniaxial in-plane anisotropy is observed, which results in the two easy axes being inequivalent. (C) 1996 American Institute of Physics.