Abstract
The electronic structures of small cobalt clusters have been calculated within the local spin density approximation using the LCAO method. The calculations were done for simple geometries with the optimized number of interatomic bonds, and both for the bond length of the cobalt dimer and the bulk metal. The Fermi energy is found to be smaller for Co N clusters withN=3, 4, 5 andN>10 than for the other ones. The variation of the Fermi energy with the cluster size correlates in a striking way with the observed H2 tendency for chemisorption as found for cobalt clusters in a supersonic beam. Furthermore, the magnetic moments are somewhat smaller for these active clusters. In addition the lowest unoccupied levels of majority spin appear close to the highest occupied levels of minority spin which is not the case for the inert clusters.
Similar content being viewed by others
References
Feuerbacher, B., Fitton, B., Willis, R.F.: Photoemission and the electronic properties of surfaces. New York: John Wiley and Sons 1979
Rhodin, T.N., Ertl, G.: The nature of the surface chemical bond. Amsterdam: North Holland 1979
King, D.A., Woodruff, D.P.: The chemical physics of solid surfaces and hetrogenous catalysis. Vol. 1. Clean Solid Surfaces. Vol 2. Adsorption at Solid Surfaces. Vol. 3. Chemisorption Systems. Vol. 4. Fundamental Studies of Hetrogenous Catalysis. Amsterdam: Elsevier 1983
Langerth, D., Suhl, H.: Many-body phenomena at surfaces. Orlando, Florida: Academic Press 1984
Somorjai, G.A.: Science227, 902 (1985)
Shustorovich, E., Baetzhold, R.C.: Science227, 876 (1985)
Shustorovich, E., Baetzhold, R.C., Muetterties, E.L.: J. Phys. Chem.87, 1100 (1983)
Kasemo, B., Lundqvist, B.I.: Comm. At. Mol. Phys.14, 229 (1984)
Nørskov, J.K., Houmøller, A., Johansson, P.K., Lundqvist, B.I.: Phys. Rev. Lett.46, 257 (1981)
Harris J., Andersson S.: Phys. Rev. Lett.55, 1583 (1985)
Blyholder, G.: J. Phys. Chem.68, 2772 (1964)
Plummer, E.W., Eberhardt, W.: Adv. Chem. Phys.49, 533 (1982)
Sung Shen-Shu, Hoffmann, R.: J. Am. Chem. Soc.107, 578 (1985)
Hamilton, J.F., Baetzold, R.C.: Science,205, 1213 (1979)
Riley, S.J., Parks, E.K., Nieman, G.C., Pobo, L.G., Wexler, S.: J. Chem. Phys.80, 1360 (1984)
Richtsmeier, S.C., Parks, E.K., Lin, K., Pobo, L.G., Riley, S.J.: J. Chem. Phys.82, 3659 (1985)
Parks, E.K., Lin, K., Richtsmeier, S.C., Pobp, L.G., Riley, J.S.: J. Chem. Phys.82, 5470 (1985)
Geusic, M.E., Morse, M.D., Smalley, R.E.: J. Chem. Phys.82, 590 (1985)
Whetten, R.L., Cox, D.M., Trevor, D.J., Kaldor, A.: Phys. Rev. Lett.54, 1494 (1985); J. Phys. Chem. 89, 566 (1985)
Hohenberg, P., Kohn, W.: Phys. Rev.136, B864 (1964)
Kohn, W., Sham, L.J.: Phys. Rev.140, A 1133 (1965)
von Barth, U., Hedin, L.: J. Phys.C5, 1629 (1972)
Delley, B., Ellis, D.E.: J. Chem. Phys.76, 1949 (1982)
Delley, B., Freeman, A.J., Ellis, D.E.: Phys. Rev. Lett.50, 488 (1983)
Ellis, D.E., Delley, B.: In: Local density approximations in quantum chemistry and solid state physics. Dahl, J.P., Avery, J. (eds.). New York: Plenum Publ. Corp. 1984
Delley, B., Jarlborg, T., Freeman, A.J., Ellis, D.E.: J. Magn. Magn. Mater31–34, 549 (1983)
Huber, K.P., Herzberg, G.: Constants of diatomic molecules. New York: Van Nostrand Reinhold Comp. 1979
Slater, J.C.: Quantum theory of molecules and solids. Vol. 2, New York: McGraw-Hill Book Comp. 1965
Apai, G., Hamilton, J.F., Stohr, T., Thompson, A.: Phys. Rev. Lett.43, 165 (1979)
Delley, B., Ellis, D.E., Freeman, A.J., Baerends, E.J., Post, D.: Phys. Rev.B27, 2132 (1983)
Koutecký, J., Paccioni, G., Jeung, G.H., Hass, E.C.: Surf. Sci.156, 650 (1984)
Martins, J.L., Buttet, J., Car, R.: Phys. Rev.B31, 1804 (1985)
Scillard, J.E., Hoffmann, R.: J. Am. Chem. Soc.106, 2006 (1984) This work gives references to experimental and theoretical works on metallorganic compounds and surfaces
Nordlander, P., Holloway, S., Norskov, J.K.: Surf. Sci136, 59 (1984). This work gives references to earlier studies of hydrogen chemisorption on surfaces
Siegbahn, P.E.M., Blomberg, M.R.A., Bauschlicher Jr, C.W.: J. Chem. Phys.81, 1373 (1984)
Moore, C.E.: Atomic Energy Levels. NBS Circ. 467 Washington DC 1971
Moruzzi, V.L., Janak, J.F., Williams, A.R.: Calculated electronic properties of metals. New York: Pergamon Press Inc. 1978
Myers, H.P., Sucksmith, W.: Proc. R. Soc. London Ser.A207, 427 (1951)
Rodbell, D.S.: Proceedings of the International Conference Magnetism and Crystallography, Kyoto, 1961; J. Phys. Soc. Jpn,17, Suppl. B–I, 313 (1962)
Hoffmann, R., Woodward, R.B.: The conservation of orbital symmetry. New York: Academic Press 1970
Paul, J., Rosén, A.: Surf. Sci.127, 193 (1983)