LAUSR

Bi2Te3 is deposited by hot wall epitaxy in an attempt to form nanosheets on epitaxially-grown ferromagnetic layers of Fe, Fe3Si and Co2FeSi. Bi2Te3 reacts strongly with pure Fe, producing FeTe2. The reaction is suppressed for silicides Fe3Si and Co2FeSi. For the latter, partial incorporation of Co into the Bi2Te3 islands occurs at high temperatures, causing magnetic doping of the topological insulator. Although (0001) remains to be the favored growth orientation on Fe3Si and Co2FeSi, non-(0001)-oriented three-dimensional islands dominantly coexist on these surfaces further strengthening the growth characteristic on GaAs and contrary to the overwhelming formation of the nanosheets on Si and SiO2. Deterioration of the magnetic properties of the ferromagnetic layers by heat treatment in the overgrowth is confirmed to be not significant. In addition, we show the surface plasmon emission in the visible energy range from the nanoislands. Finding the material combinations for which the overlayer-substrate reaction is circumvented opens the way to epitaxially create topological-insulator–ferromagnet multiple layer structures.