Stoichiometry and Bravais lattice diversity: an ab initio study of the GaSb(001) surface

0337230 - FZÚ 2010 RIV US eng J - Journal Article
Romanyuk, Olexandr - Grosse, F. - Braun, W.
Stoichiometry and Bravais lattice diversity: an ab initio study of the GaSb(001) surface.
[Stechiometrie a Bravais mřižková rozmanitost: ab initio studium GaSb(001) povrchu.]
Physical Review. B. Roč. 79, č. 23 (2009), 235330/1-235330/7. ISSN 1098-0121
Grant - others:GRF(DE) GZ:436 TSE 113/62/0-1
Institutional research plan: CEZ:AV0Z10100521
Keywords : GaSb(001) surface * molecular beam epitaxy (MBE) * DFT
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 3.475, year: 2009

We study the family of GaSb(001)-(4x3) reconstructions by ab initio density-functional theory. For each possible surface stoichiometry between the well-known Sb-poor alpha(4x3) and Sb-rich beta(4x3) phases, we find thermodynamically stable reconstructions. Surface energies of (4x3) unit cells shifted relative to each other are computed for the thermodynamically stable phases. Especially, the energetic costs for unit-cell shifts along the [1-10] direction with the length of one in-plane surface lattice constant are very low. In a comparative study, we show that this is similar to the beta2(2x4) reconstructed GaAs(001) surface with a one-dimensional disorder along [1-10], but different from the c(4x4) reconstruction. The diversity in surface stoichiometry and unit-cell shape allows us to explain the contradicting experimental results obtained by scanning tunneling microscopy and surface-diffraction techniques at finite substrate temperatures.

Povrchové reconstrukce GaSb(001) byla studována ab initio metodou na základě density-functional teorie. Pro každou povrchovou stechiometrii GaSb(001) (4x3) buňky byla nalezena termodynamicky stabilní rekonstrukce. Byla určena povrchová energie těchto buněk posunutých mezi sebou. Byl vysvětlen nesoulad mezi daty nameřenými tunelovacim skanovacím mikroskopem a difrakční metodou.
Permanent Link: http://hdl.handle.net/11104/0181284