Structure determination of metastable cobalt films

Abstract

The bulk atomic structure of cobalt films deposited on GaAs has been unequivocally determined to be the body-centered-cubic metastable phase. A comparison of the conversion-electron x-ray-absorption fine structure of Co films deposited on GaAs(110) with similar measurements for the stable phases of hcp Co, fcc Cu, and bcc Fe establishes the Co bcc phase with a lattice constant of 2.82\ifmmode\pm\else\textpm\fi{}0.01 A\r{}. Furthermore, this first application of the technique to single-crystal epitaxial films shows it to be a most powerful procedure for establishing their crystal structure.