We demonstrate ability to form self-assembled nanowires of Yb silicide on Si(0 0 1) by means of solid phase epitaxy. Such nanowires, in contrast to those of other rare earth silicides, are shown to exhibit an unexpectedly wide variety of orientations with respect to the Si substrate. Their spontaneous formation is explained in terms of the hexagonal AlB2 structure of silicon-rich Yb disilicide. (C) 2003 Elsevier B.V. All rights reserved.