Surfactant Mediated Epitaxial Growth of Co on Au(111) Surface

Abstract

We have chosen Bi as the surfactant atom in the heteroepitaxial growth of Co on Au(111). It was found that Bi induces layer-by-layer (LBL) growth at room temperature. With pre-deposition of 0.2 ∼ 0.8Å Bi on Au(111) prior to the evaporation of Co, more long-lasting RHEED intensity oscillations were observed and this implies that it induces the LBL growth of Co film. The result of the dependence of the growth behavior as a function of Bi layer thickness suggests that there is a suitable amount of Bi surfactant layer that induces the smoother LBL growth. A surface segregation of Bi was found at the top of surface and acts as a surfactant by promoting the interlayer transport.

Induced Superconductivity and Engineered Josephson Tunneling Devices in Epitaxial (111)-Oriented Gold/Vanadium Heterostructures

“…2 )] 1/2 = 4.07 ± 0.25 Å, which matches well with other reported values. 16 In fact, these in situ RHEED results tell us the epitaxial relation between Au and the substrate as…”

“…14 Due to the large surface energy of Ag or Au the grown layer usually forms island type growth mode, which prevents them from forming continuous and smooth films in thicknesses down to a few nanometers. 15 Magnetic seed layers, such as Fe, Co, and so forth, have been reported as buffer for growing thin (<50 nm) Ag or Au films, 16,17 but this does not allow inducing superconductivity. Nonmagnetic seed layer (Nb) has been demonstrated to facilitate the growth of Au thin film; 18 however, the Nb is too thin (∼1 nm) to show any superconductivity.…”