Faulted surface layers in dysprosium silicide nanowires

The crystallography and microstructure of epitaxial dysprosium silicide nanowires on Si(001) have been studied using high-resolution transmission electron microscopy. Islands grown at 750 degreesC have a compact three-dimensional shape and are identified as hexagonal DySi2. Islands grown at 650 degreesC have an elongated nanowire (NW) shape. They contain one or two layers of hexagonal silicide at the buried interface and two to three surface layers with faulted stacking similar to tetragonal DySi2. The faulted layers are believed to provide stress relief during growth of the coherently strained NW islands.