Growth modes of Fe(110) revisited: a contribution of self-assembly to magnetic materials

Abstract

We have revisited the epitaxial growth modes of Fe on W(110) and Mo(110), and\npropose an overview or our contribution to the field. We show that the\nStranski-Krastanov growth mode, recognized for a long time in these systems, is\nin fact characterized by a bimodal distribution of islands for growth\ntemperature in the range 250-700°C. We observe firstly compact islands\nwhose shape is determined by Wulff-Kaischev's theorem, secondly thin and flat\nislands that display a preferred height, ie independant from nominal thickness\nand deposition procedure (1.4nm for Mo, and 5.5nm for W on the average). We\nused this effect to fabricate self-organized arrays of nanometers-thick stripes\nby step decoration. Self-assembled nano-ties are also obtained for nucleation\nof the flat islands on Mo at fairly high temperature, ie 800°C. Finally,\nusing interfacial layers and solid solutions we separate two effects on the\npreferred height, first that of the interfacial energy, second that of the\ncontinuously-varying lattice parameter of the growth surface.\n