ULTRATHIN FILMS OF Co and Fe on FeRh{001} AND FeRh{110}

Abstract

Ultrathin films of Co and Fe have been grown on two clean surfaces of the binary alloy FeRh, namely the {110} and the {001} surface, and have been studied with quantitative low-energy electron diffraction (QLEED). On FeRh{110}, 25-Å-thick Co films are epitaxial, but not pseudomorphic, and expose the basal (0001) plane of hcp Co. On FeRh{001}, 20-Å-thick Co films are pseudomorphic and assume the structure of strained [Formula: see text] hcp Co — a phenomenon already observed on Co films grown on FeAl{001}. Iron films, by contrast, are pseudomorphic both on FeRh{110} and on FeRh{001}, assuming a strained bcc structure. For all films, QLEED analysis determines both the bulk and the first interlayer spacings.