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NANOSYSTEMS: PHYSICS, CHEMISTRY, MATHEMATICS, 2013, 4 (6), P. 823-833

INFLUENCE OF Sb CONTENT ON PHASE COMPOSITION CHANGE OF NANOSCALED Co-Sb FILMS DEPOSITED ON HEATED SUBSTRATE

Yu. N. Makogon – National Technical University of Ukraine «KPI», 03056, Peremogy Avenue, 37, Kiev, Ukraine; y.makogon@kpi.ua
E.P. Pavlova – National Technical University of Ukraine «KPI», 03056, Peremogy Avenue, 37, Kiev, Ukraine; el_pavlova@inbox.ru
S. I. Sidorenko – National Technical University of Ukraine «KPI», 03056, Peremogy Avenue, 37, Kiev, Ukraine; sidorenko@kpi.ua
R. A. Shkarban – National Technical University of Ukraine «KPI», 03056, Peremogy Avenue, 37, Kiev, Ukraine; haben@ukr.net

The subject of this study is the formation of the phase composition and structure in nanoscaled CoSb_x (30 nm) (1.82≤x≤4.16) lms deposited by molecular-beam epitaxy on substrates of oxidized monocrystalline silicon at 200°C and the following thermal treatment in vacuum from 300-700 °C. It is established that after deposition, the lms are polycrystalline without texture. With increased Sb content, the formation of the phase composition in the lms takes place in such a sequence as is provided by the phase diagram for the bulk state of the Co-Sb system. With annealing in vacuum at temperatures above 450-500 °C, sublimation occurs not only for the crystalline Sb phase, but for the antimonides as well. This is reflected in the phase composition change by the following chemical reactions: CoSb₂→ (600°C) Sb↑ = CoSb, CoSb₃→ (600°C) Sb↑ = CoSb₂, CoSb₃+Sb↑→ (600°C) CoSb₃ and leads to increases in the amounts of the CoSb and CoSb₂ phases and decreases in the amounts of CoSb₃. CoSb_x(30 nm) (1.82≤x≤4.16) lms are found to be thermostable up to ≈350°C.

Keywords: skutterudite, phase, film, sublimation.

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