Jm. Mccoy et al., QUANTITATIVE-ANALYSES OF RHEED PATTERNS FROM MBE GROWN GAAS(001)-2X4 SURFACES - COMMENT, Surface science, 306(1-2), 1994, pp. 247-251
In a recent paper (Y. Ma, S. Lordi, P.K. Larsen and J.A. Eades, Surf S
ci. 289 (1993) 47) a multislice formalism combined with an edge-patchi
ng method was used in the quantitative analysis of RHEED patterns from
the As-rich GaAs(001)-2 x 4 surface. We correct certain of the statem
ents made in this paper concerning the unreliability of previously rep
orted RHEED calculations and RHEED surface structure analyses. We then
discuss details of the multislice calculations of Ma et al. and the p
attern fitting procedure used. With reference to our own RHEED calcula
tions for this surface, using a 2D Bloch wave formulation, we conclude
that there are problems in the pattern fitting procedure and that thi
s method can by no means be considered as reliable as reported in earl
ier RHEED analyses.