SURFACE AND NEAR-SURFACE STRUCTURE OF FE-CO LAYERS BY SCATTERING-INTERFERENCE OF PRIMARY ELECTRONS

We studied the Co/Fe bi-and multilayer growth on Fe single crystal usi ng the primary-beam diffraction modulated electron emission (PDMEE) te chnique. This approach enables a chemical selected structural characte rization of both surface and buried layers and interfaces to be perfor med. Co growth on the Fe(001) surface was studied in the 3-70 ML cover age range. The transition from the initial epitaxial bcc phase of the Co film to the stable hcp phase was found to occur rather abruptly at 25-30 ML coverage, a value larger than previously reported in the lite rature. Subsequent Fe deposition on the Co hcp film recovers the bcc s tructure in the sandwiched Co layer. However, removal of the Fe epilay er by mild sputtering results again in an hcp Co film.