Structure and growth mode of metastable fcc cobalt ultrathin films on Cu(001) as determined by angle-resolved X-ray photoemission scattering

• Published in: Surface science 1990-11, Vol.237 (1-3), p.141-152
• Main Authors: HONG LI, TONNER, B. P
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Metals. Metallurgy; Physics; Solid surfaces and solid-solid interfaces; Surface and interface dynamics and vibrations; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(90)90527-f

The structure and growth mode of metastable fcc Co(001) films on Cu(001)substrates were determined by using angle-resolved X-ray photoemission scattering (ARXPS). The results show that at room temperature on Cu(001), Co grows with a small but measureable deviation from ideal layer-by-layer mode, with the formation of two-layer thick islands for average coverages below two monolayers (ML). When the coverage exceeds two monolayers, Co grows to a well-ordered fcc-(001) film via a layer-by-layer growth mode. The combination of low-energy electron diffraction (LEED) and ARXPS as the stuctural probe shows that high quality fcc films of Co of up to 20 ML thickness can be stabilized at room temperature by epitaxial growth. Upon heating to 400 deg C, an unusual structure is formed in which substrate Cu atoms diffuse through the cobalt film to form a flat layer on top of an ordered fcc Co film. 44 ref.--AA