Formation of iron silicide nanodots on Si(1 1 1)–3×3Ag

Iron silicide dots of nanometer size were grown on Si(1 1 1)–3×3Ag substrates. Formation and magnetic properties of the dots have been investigated with scanning tunneling microscopy, low-energy electron diffraction, Auger electron spectroscopy and magnetic ex-situ measurements. Effect of passivating the Si substrate with Ag was discussed. The dots were found ferromagnetic and its composition was deduced to be ∼Fe3Si. They nucleate preferentially at step edges than on terraces. Use of vicinal substrates thus enables fabricating arrays of the dots.