THERMALLY ACTIVATED PROCESSES OF THE PHASE COMPOSITION AND STRUCTURE FORMATION OF THE NANOSCALED Co–Sb FILMS

Abstract

It is investigated the formation of the phase composition and structure in the nanoscaled CoSbх (30 nm) (1.82 ≤ х ≤ 4.16) films deposited by the method of molecular-beam epitaxy on the substrates of the oxidated monocrystalline silicon at 200 С and following thermal treatment in vacuum in temperature range of 300–700 С. It is established that the films after the deposition are polycrystalline without texture. With increase in Sb content the formation of the phase composition in the films takes place in such sequence as this is provided by phase diagram for the bulky state of the Co–Sb system. At annealing in vacuum at temperature above 450–500 С a sublimation not only of the crystalline Sb phase but from the antimonides occurs. This is reflected on the phase composition change by following chemical reactions: CoSb₂ Sb↑ = CoSb, CoSb₃ Sb↑= CoSb₂, CoSb₃ + Sb↑ CoSb₃ and leads to increase in amount of the СоSb and СоSb2 phases and decrease in amount of the СоSb3. CoSbx (30 nm) (1.8 < х < 4.16) films under investigation are thermostable up to 350 С