U105888.pdf (4.76 MB)
The atomic structure of the indium antimonide (001) surface
thesisposted on 2014-12-15, 10:40 authored by Nigel Jones
The atomic structures of the c(8x2) and c(4x4) reconstructions of InSb(001) have been determined using surface X-ray diffraction. Large in-plane and out-of-plane data sets were measured for each of the reconstructions, enabling a detailed model of the precise atomic structure to be calculated for the first time. A new model, consisting of chains of indium atoms, separated by parallel pairs of antimony dimers on top of an antimony terminated bulk, has been proposed for the InSb(001)-c(8x2) reconstruction. The model represents a significant departure from any of the models previously suggested for the c(8x2) reconstruction of the III-V (001) surfaces. The InSb(001)-c(4x4) surface is found to be consistent with a previously reported missing dimer model. It is proposed, however, that the groups of dimers are incomplete in approximately one third of the cases. The dimer bond lengths and the corresponding bond angles, have also been determined for the first time. The c(4x4) reconstruction is found to be notably flatter than the c(8x2) reconstruction.;A surface phase transition study from the highly ordered c(4x4) phase to a disordered asymmetric(1x3) phase, shows that a fully reversible transition takes place. The results indicate that the transition is a consequence of random desorption of antimony dimer atoms in distinct isolated regions, rather than a general reduction in domain size.;Oxide removal from the InSb(001) surface has been achieved using a number of techniques. The quality of the resulting surfaces was determined from the reflected X-ray intensity and the in-plane fractional-order reflections.
Date of award1998-01-01
Awarding institutionUniversity of Leicester