The Structure of Sb-Terminated GaAs(001) Surfaces
NAVAL RESEARCH LAB WASHINGTON DC
Pagination or Media Count:
We have studied the structure of Sb-terminated GaAs001 surfaces using reflection high energy electron diffraction, X-ray photoelectron spectroscopy, and scanning tunneling microscopy STM. Clean, As-terminated 24 surfaces were prepared by molecular beam epitaxy and then exposed to Sb4 at 490 C, producing a 28-reconstructed surface terminated with 1 ML of Sb. Re-heating such a surface to 460 C in vacuum returns the surface to a 24 reconstruction with approximately 0.5 ML Sb remaining. STM reveals a complex, but well-ordered structure on the 28 surface for which a tentative model is proposed. On the 24 surface, our results clearly show that each unit cell is terminated by three dimers, with two-thirds Sb dimers and one-third As dimers. These results contrast with previous proposals that the Sb-induced 24 surface is terminated solely by one or two Sb dimers.
- Inorganic Chemistry
- Atomic and Molecular Physics and Spectroscopy