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Self-Assembled Nanostructures on VSe2 Surfaces Induced by Cu Deposition

Published online by Cambridge University Press:  28 September 2005

Erdmann Spiecker
Affiliation:
Center for Microanalysis, Faculty of Engineering, University of Kiel, Kaiserstrasse 2, D-24143 Kiel, Germany
Stefan Hollensteiner
Affiliation:
Center for Microanalysis, Faculty of Engineering, University of Kiel, Kaiserstrasse 2, D-24143 Kiel, Germany
Wolfgang Jäger
Affiliation:
Center for Microanalysis, Faculty of Engineering, University of Kiel, Kaiserstrasse 2, D-24143 Kiel, Germany
Hans Haselier
Affiliation:
Institute for Solid State Research, Research Center Jülich, D-52425 Jülich, Germany
Herbert Schroeder
Affiliation:
Institute for Solid State Research, Research Center Jülich, D-52425 Jülich, Germany
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Abstract

Analytical transmission electron microscopy (TEM) and scanning electron microscopy (SEM) have been applied for the characterization of evolution, lateral arrangements, orientations, and the microscopic nature of nanostructures formed during the early stages of ultrahigh vacuum electron beam evaporation of Cu onto surfaces of VSe2 layered crystals. Linear nanostructure of relatively large lateral dimension (100–500 nm) and networks of smaller nanostructures (lateral dimension: 15–30 nm; mesh sizes: 500–2000 nm) are subsequently formed on the substrate surfaces. Both types of nanostructures are not Cu nanowires but are composed of two strands of crystalline substrate material elevating above the substrate surface. For the large nanostructures a symmetric roof structure with an inclination angle of ∼30° with respect to the substrate surface could be deduced from detailed diffraction contrast experiments. In addition to the nanostructure networks a thin layer of a Cu-VSe2 intercalation phase of 3R polytype is observed at the substrate surface. A dense network of interface dislocations indicates that the phase formation is accompanied by in-plane strain. We present a model that explains the formation of large and small nanostructures as consequences of compressive layer strains that are relaxed by the formation of rooflike nanostructures, finally evolving into the observed networks with increasing deposition time. The dominating contributions to the compressive layer strains are considered to be an electronic charge transfer from the Cu adsorbate to the substrate and the formation of a Cu-VSe2 intercalation compound in a thin surface layer.

Type
Special Issue: Frontiers of Electron Microscopy in Materials Science
Copyright
© 2005 Microscopy Society of America

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References

REFERENCES

Adelung, R., Ernst, F., Scott, A., Tabib-Azar, M., Kipp, L., Skibowski, M., Hollensteiner, S., Spiecker, E., Jäger, W., Gunst, S., Klein, A., Jägermann, W., Zaporojtchenko, V., & Faupel, F. (2002a). Self-assembled nanowire networks by deposition of copper onto layered-crystal surfaces. Adv Mater 14, 10561060.Google Scholar
Adelung, R., Hartung, W., & Ernst, F. (2002b). Fabrication of Cu-induced networks of linear nanostructures on different length scales. Acta Mater 50, 49254933.Google Scholar
Adelung, R., Kunz, R., Ernst, F., Kipp, L., & Skibowski, M. (2003). Self-organized structures on flat crystals: Nanowire networks formed by metal evaporation. In Advances in Solid State Physics 43, B. Kramer, (Ed.), pp. 463476. Heidelberg: Springer.
Baughman, R.H., Zakhidov, A.A., & de Heer, W.A. (2002). Carbon nanotubes: The route toward applications. Science 297, 787792.Google Scholar
De Ridder, R., van Tendeloo, G., van Landuyt, J., van Dyck, D., & Amelinckx, S. (1976). Microstructural study of copper-intercalated niobium disulphide and tatalum disulphide CuxNbS2 and CuxTaS2. Part I. Phys Stat Sol A 37, 591606.Google Scholar
De Ridder, R., van Tendeloo, G., van Landuyt, J., van Dyck, D., & Amelinckx, A. (1977). Microstructural study of copper-intercalated niobium disulphide and tatalum disulphide CuxNbS2 and CuxTaS2. Part III. Phys Stat Sol A 39, 383399.Google Scholar
Hollensteiner, S., Spiecker, E., Dieker, C., Jäger, W., Adelung, R., Kipp, L., & Skibowski, M. (2003a). Self-assembled nanowire formation during Cu deposition on atomically flat VSe2 surfaces studied by microscopic methods. Mater Sci Eng C 23, 171179.Google Scholar
Hollensteiner, S., Spiecker, E., & Jäger, W. (2005). Metal-induced nanostructures on surfaces of layered chalcogenides. Appl Surf Sci 241, 4955.Google Scholar
Hollensteiner, S., Spiecker, E., Jäger, W., Haselier, H., & Schroeder, H. (2003b). Analyses of nanostructure formation by Cu deposition onto VSe2 surfaces. Microsc Microanal 9 (Suppl. 3), 216217.Google Scholar
Ibach, H. (1997). The role of surface stress in reconstruction, epitaxial growth and stabilization of mesoscopic structures. Surf Sci Rep 29, 193263.Google Scholar
Ramirez, C. & Schattke, W. (2001). Diffusion and intercalation of alkali metals in transition metal dichalcogenides. Surf Sci 482–485, 424429.Google Scholar
Rathner, P. (1986). Topotactic redox reactions of metal dichalcogenides. Dissertation, University of Münster, Germany.
Remškar, C., Marinković, V., Prodan, A., & škraba, Z. (1995). Intercalation of vacuum deposited silver 1T-TaS2 and its influence on charge-density waves. Surf Sci 324, L367L370.Google Scholar
Remškar, C., Popović, A., & Starnberg, H.I. (1999). Stacking transformation and defect creation in Cs intercalated TiS2 single crystals. Surf Sci 430, 199205.Google Scholar
Sollmann, K. (1995). Investigation of the structure and dynamics of copper and silver intercalation compounds of the transition metal dichalcogenides 1T-TiS2, 1T-VS2, 1T-VSe2 and 2H-NbS2. Dissertation, Technical University of Berlin, Germany.
Spiecker, E. (2003). Interface and surface phenomena of transition metal dichalcogenide crystals: Ultrathin layer epitaxy and self-assembling of nanostructures. Microsc Microanal 9 (Suppl. 3), 300301.Google Scholar
Starnberg, H.I., Brauer, H.E., Holleboom, L.J., & Hughes, H.P. (1993). 3D-to-2D transition by Cs intercalation of VSe2. Phys Rev Lett 70, 31113114.Google Scholar
Tenne, R. & Rao, C.N.R. (2004). Inorganic nanotubes. Phil. Trans. R. Lond. A 362, 20992125.Google Scholar
Tsuda, K. & Tanaka, M. (1995). Refinement of crystal structure parameters using convergent-beam electron diffraction: The low-temperature phase of SrTiO3. Acta Cryst A 51, 719.Google Scholar
van Tendeloo, G., De Ridder, R., van Dyck, D., van Landuyt, J., & Amelinckx, S. (1976). Microstructural study of copper-intercalated niobium disulphide and tantalum disulphide CuxNbS2 and CuxTaS2. Part II. Phys Stat Sol A 38, 185198.Google Scholar
Williams, D.B. & Carter, C.B. (1996). Transmission Electron Microscopy. New York: Plenum Press.
Wilson, J.A. & Yoffe, A.D. (1969). The transition metal dichalcogenides: Discussion and interpretation of observed optical, electrical and structural properties. Adv Phys 18, 193335.Google Scholar