Quantitative low-energy electron-diffraction study of the epitaxy of Fe on Ag{001}: Questions about the growth mode

We point out contradictions among several reports relating to the mode of growth of Fe on Ag{001}, particularly between the studies done by reflection-high-energy electron diffraction (RHEED) and those done by low-energy electron diffraction (LEED). We describe qualitative LEED observations that agree with those of other workers. These observations, as well as quantitative analyses reported herein, indicate that on the samples used in all LEED experiments reported to date, the growth of Fe on Ag{001} was neither layer by layer nor of Stranski-Krastanov type. These results are inconsistent with the conclusions drawn by others from RHEED intensity oscillations. We also establish quantitatively that the structure of thicker (10-30 layers) films of Fe on Ag{001} is either the stable bcc structure of -Fe or a slight body-centered-tetragonal distortion thereof.