Morphology and atomic structure of the sputtered and annealed Mo3Si and Cr3Si (110) surfaces.

Abstract

Scanning tunneling microscopy was used to study the sputtered and annealed (110) surfaces of ${\mathrm{Mo}}_{3}$Si and ${\mathrm{Cr}}_{3}$Si. Both surfaces show extended and atomically flat terraces, but in the case of ${\mathrm{Mo}}_{3}$Si there is also a uniform distribution of Mo crystallites. This difference in morphology is discussed in terms of different preferential sputtering effects. In both cases, measured step heights show that the ideally bulk-truncated surfaces are either purely Si or metal terminated. Atomically resolved images suggest that the ${\mathrm{Mo}}_{3}$Si surface is Si terminated, but although no atomic resolution could be obtained for the ${\mathrm{Cr}}_{3}$Si surface, there are indications that this surface is instead metal terminated.