Structural Stability of Si(001) and Ge(001) in External Electric Fields
The effects of external electrostatic fields normal to surfaces, E ext , on the structural stability of Si(001) and Ge(001) have been investigated using first-principles total energy calculations. It has been shown that the c(4×2) surface is more stable than the p(2×2) surface for both Si(001) and G...
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Published in | Japanese Journal of Applied Physics Vol. 44; no. 7S; p. 5413 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
01.07.2005
|
Online Access | Get full text |
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Summary: | The effects of external electrostatic fields normal to surfaces,
E
ext
, on the structural stability of Si(001) and Ge(001) have been investigated using first-principles total energy calculations. It has been shown that the c(4×2) surface is more stable than the p(2×2) surface for both Si(001) and Ge(001) even with a finite electric field whose strength is typical of STM experiments. On the other hand, it has been revealed that the energy barrier for dimer flipping,
E
B
, shows different dependences between the Si(001)- and Ge(001)-(2×1) surfaces:
E
B
at Si(001) changes in proportion to
E
ext
, but hardly does at Ge(001). Such a difference is explained by the difference in the rehybridization of buckled dimers between the reconstructed surfaces of Si(001) and Ge(001), which originates from the difference in the s-p separation of valence orbitals between Si and Ge. |
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ISSN: | 0021-4922 1347-4065 |
DOI: | 10.1143/JJAP.44.5413 |