Publication: Surface Stability and Electronic Structure of Hydrogen and Fluorine Terminated Diamond Surfaces: A First Principles Investigation
All || By Area || By Year| Title | Surface Stability and Electronic Structure of Hydrogen and Fluorine Terminated Diamond Surfaces: A First Principles Investigation | Authors/Editors* | F.G. Sen, Y. Qi, A.T. Alpas |
|---|---|
| Where published* | Mater. Res. Soc. Symp. Proc. |
| How published* | Proceedings |
| Year* | 2009 |
| Volume | 1130 |
| Number | |
| Pages | 1130-W06-30 |
| Publisher | |
| Keywords | |
| Link | http://www.mrs.org/s_mrs/sec_subscribe.asp?DID=234068&CID=16761&SID=1&VID=113&RTID=0 |
| Abstract |
The stability and electronic structure of fully H or F terminated and mixed H and F terminated diamond (111) surfaces were studied using first principles calculations. It was found that F atoms on the surface, like H, formed sp3 type bonding with C atoms, which resulted in a more stable 1x1 configuration rather than the p-bonded 2x1 construction of clean diamond. A phase diagram showing the stable surface composition regions was constructed as a function of chemical potentials of H and F. The diagram shows that the surface with 75% F (25% H) termination was unstable. The F terminated surface was more stable than H termination due to the formation of strong ionic C-F bonding and the close packing of the large F atoms. Due to the attractive forces developed between F atoms, a close packed surface was formed. Additionally, the exposure of C to the environment became restricted because of the large size of F atoms. Hence, F terminated diamond surface was more chemically inert compared to H terminated surface. To bring two F terminated surfaces together, a large repulsive force was required due to the negative charge on F atoms, and this led to low adhesion between two F terminated diamond surfaces compared to two H terminated surfaces. |
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