標題: Photoemission study of surface state intensity resonance and dispersion of Be2C(100)
作者: Tzeng, CT
Yuh, JY
Lo, WS
Chu, RY
Tsuei, KD
光電工程學系
Department of Photonics
關鍵字: angle-resolved photoemission;carbides;insulating films;surface states;synchrotron radiation
公開日期: 10-三月-1999
摘要: We have carried out an extensive study on the surface state properties of an ionic, insulating Be2C(100) surface using angle-resolved photoemission spectroscopy. Two surface states were observed and characterized. One (S1) is derived at the Gamma-point above the valence band maximum in the fundamental gap. The other (S2) is located in the gap at the X-point. Resonance in the photoemission intensity of surface state S2 shows multiple peaks due to a surface umklapp process, similar to bulk transitions, because of large corrugation of the ionic surface. The penetration lengths deduced are about 4 Angstrom for both surface states. The dispersions of these states are very small. These two results indicate strong localization of the. surface state wave function to individual surface C atoms owing to the ionic character of this compound. That a surface state (S2) exists in a non-inverted Shockley gap is attributed to the compound structure. (C) 1999 Elsevier Science B.V. All rights reserved.
URI: http://dx.doi.org/10.1016/S0039-6028(98)00910-8
http://hdl.handle.net/11536/31454
ISSN: 0039-6028
DOI: 10.1016/S0039-6028(98)00910-8
期刊: SURFACE SCIENCE
Volume: 423
Issue: 2-3
起始頁: 232
結束頁: 242
顯示於類別:期刊論文


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  1. 000079431400016.pdf