1A.J. Zarur and J.Y. Ying, Nature 403 (2000) 65; L.X. Chen, T. Rajh, Z. Wang and M.C. Thurnauer, J. Phys. Chem. B 101 (1997) 10688; S. Chen, T. Ida and K. Kimura, J. Phys. Chem. B 102 (1998) 6169; R. Nitsche, M. Winterer, M. Croft and H. Hahn, Nucl. Instr. Meth. B 97 (1995) 127. 2Z.Y. Wu, F. Jollet, S. Goda, N. Thromat, M. Gautier-Soyer and T. Petit, J. Phys: Condens. Matter11 (1999) 7185. 3 D.R. Mullins, S.H. OverBury and D.R. Huntly, Surface Science 409 (1998) 307. 4 S. Tsunekawa. T. Fukuda and A. Kasuya, Surface Science 457 (2000) L457. 5S.Y. Wang, Z.P. Qiao, W. Wang and Y.T. Qian, J. Alloys Compounds 305 (2000) 121. 6J.W. Allen, in Synchrotron Radiation Research-Surface and Interface Science, ed. R. Z. Bachrach (Plenum Press, New York, 1992, Vol.1) p. 253. 7M. Matsumoto, K. Soda, K. Ichikawa, S. Tanaka, Y. Taguchi, K. Jouda, 0. Aita, Y. Tezuka and S. Shin, Phys. Rev. B 50 (1994) 11340. 8W.Z. Bin, W.L. Ping and H.G. Yan, Chin. J. Appl. Chem. 16 (1999) 9. 9J. Zhang, Private communication. 10S.C. Wu, K. Xun, J.Z. Deng, J. Yao, F.Q. Liu, Z.Q. Wang, R.S. Han and Z.N. Gu, Phys. Rev. B 47 (1993) 13830. 11D.D. Koelling, A.M. Boring and J.H. Wood, Solid State Commun. 47 (1983) 227. 12F. Marabelli and P. Wachter, Phys. Rev. B 36 (1987) 1238. 13M. Richter, M. Meyer, M. Pahler, T. Prescher, E.V. Raven, B. Sonntag and H.E. Wetzel, Phys. Rev. B 39 (1989) 5666. 14P. Strange, A. Svane, W.M. Temmerman, Z. Zsotek and H. Winter, Nature 399 (1999) 756. 15B. Johansson and M.S.S. Brooks, in Handbook on the Physics and Chemistry of Rare-Barth (North-Holland, Amsterdam, 1993, Vol.17) p.149; M.R. Norman, Phys. Rev. Lett. 53 (1984) 1673; E. Weschke, Phys. Rev. Lett. 69 (1992) 1792. 16O. Gunnarsson and K. Sch?nhammer, Phys. Rev. B 28 (1983) 4315. |