Growth of Co films on Cu(111) studied in real space

Abstract

The atomic structure of Co films deposited on Cu(111) at room temperature is studied by imaging backscattered secondary electrons. The patterns show in-registry growth for the first two atomic layers.The next two monolayers show features of the fcc as well as the hcp structure. The hexagonal structure characteristic for bulk Co is found for subsequent layers.Thin films of magnetic metals epitaxially grown on nonmagnetic substrates primarily offer the possibility of studying magnetic phenomena in two dimensions. It is believed that the magnetic properties, like anisotropy, are intimately connected to the very atomic structure of these films. So it is not surprising that recently much effort has been dedicated to study the growth of a model system like Co films on Cu(111), as well as epitaxial Co/Cu superlattices. A further point of interest is that Co films on Cu may serve to stabilize the metastable fcc phase of Co. A natural question arises up to what thickness the fcc phase remains really stable.Cobalt metal crystalhzes in both the face-centeredcubic (fcc) and the hexagonal-closed-packed (hcp) structures with the transition temperature of 706+4 K for the hcp -+fcc transition and 691+4 K for the fcc -+hcp transition. ' The crystallographic data for bulk metals of Co and Cu are also very similar. These involve a negligible

The Structure of Fe on Al(001)

“…Hence, SEI is well suited for the structural study of growing films and alloying at metal-metal interfaces. 12,13 Similar to X-ray photoelectron diffraction (XPD), SEI is based on the forward scattering of emitted electrons along the atomic rows in a crystal. 14 The physics and some applications of SEI have been described elsewhere.…”

hcp-to-fcc stacking switch in thin cobalt films induced by Cu capping

“…Because of the intrinsic coupling between structure and magnetism many efforts have been spent in retrieving the structure and morphology of the films. For Co/Cu͑111͒, on which we focus in the present paper, many different surface structure sensitive techniques have been applied such as visual low-energy electron diffraction ͑LEED͒, [1][2][3] angle-resolved photoelectron diffraction, [2][3][4][5] Auger electron forward scattering, 3 scanning tunneling microscopy ͑STM͒, 6,7 thermal energy atom scattering, 8 low-energy ion scattering, 9 angle-resolved secondary electrons backscattering, 10 x-ray-absorption fine-structure measurements ͑EXAFS͒, 11,12 and quantitative LEED. 8,13,14 Structural information for Co/Cu͑111͒ superlattices has been obtained by nuclear magnetic resonance ͑NMR͒ experiments [15][16][17][18] and x-ray diffraction.…”

Co nanocrystallites on an icosahedral Al-Pd-Mn quasicrystal

“…The arrangement of the LEED spots suggests the growth of five Co domains in the bcc structure exposing their (110) faces. Considering a mean free path of low-energy electrons of a few Å [8], the growth of bcc Co domains for multilayer deposits is reasonable.…”

“…The deposition rate of 0.63 AE 0.02 Å /min was calibrated in a separate experiment by evaporating Co onto a polycrystalline Cu and monitoring the L 3 M 4,5 M 4,5 Auger signals of Cu during deposition. For the inelastic mean free path of electrons in Co, at corresponding energies, 4 Å was chosen as the most reliable value [8]. The surface and the near-surface atomic order was investigated using low-energy electron diffraction (LEED) [9] and secondary-electron imaging (SEI) [10].…”