Ordering of organic molecules on passivated reactive substrates: PTCDA on O-p(2×2)–Ni( [formula omitted])

• Published in: Surface science Vol. 498; no. 1; pp. 161 - 167
• Main Authors: Tiba, M.V., Kurnosikov, O., Flipse, C.F.J., Koopmans, B., Swagten, H.J.M., Kohlhepp, J.T., de Jonge, W.J.M.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.02.2002; Amsterdam Elsevier Science; New York, NY
• Subjects: Adsorption and desorption kinetics; evaporation and condensation; Aromatics; Condensed matter: structure, mechanical and thermal properties; Evaporation and sublimation; Exact sciences and technology; Molecular beam epitaxy; Nickel; Oxygen; Physics; Scanning tunneling microscopy; Solid-fluid interfaces; Surface structure, morphology, roughness, and topography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Aromatics; Scanning tunneling microscopy; Oxygen; Molecular beam epitaxy; Nickel; Surface structure, morphology, roughness, and topography; Evaporation and sublimation; Crystal growth; Organic dianhydride; Multilayer; Crystal orientation; Polycyclic compound; Surface topography; Experimental study; STM; Surface structure; Fluid solid interface; Transition elements; Heterocyclic oxygen compounds; Crystal nucleation; Crystal faces
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(01)01682-X

The ordering of an organic molecular layer on a ferromagnetic substrate is studied using scanning tunnelling microscopy. Highly ordered layers of perylene-tetracarboxylic-dianhydride (PTCDA) were prepared by vacuum sublimation on an oxygen precovered Ni(1 1 1) surface. The structure of thin layers of PTCDA deposited at room temperature was investigated as a function of growth rates and thickness. It is demonstrated that oxygen passivation reduces the reactivity sufficiently to lead to well-ordered overlayers of PTCDA. For thin films grown at low deposition rates, a herringbone-like structure has been observed. This structure is consistently observed in the islands with typically 100 nm in diameter and 1–2 ML thickness. Depositing thicker films at higher deposition rates results in polycrystalline islands. Within the polycrystalline islands two distinct stripe-like phases are observed in domains with a lateral size of typically 10 nm. The potential impact of these results for organo-metallic spintronic devices is addressed.