Mössbauer Effect Study Of Iron Thin Films On Si/SiOx Substrate And Iron Phases At Deposited Carbon Nanotubes

0354513 - ÚFM 2011 RIV US eng C - Conference Paper (international conference)
Schneeweiss, Oldřich - David, Bohumil - Jašek, O. - Zajíčková, L. - Vondráček, Martin - Zbořil, R. - Mašláň, M.
Mössbauer Effect Study Of Iron Thin Films On Si/SiOx Substrate And Iron Phases At Deposited Carbon Nanotubes.
Mössbauer Spectroscopy in Materials Science - 2010. Melville, New York: American Institute of Physics, 2010 - (Tuček, J.; Miglierini, M.), s. 90-95. AIP Conference Proceedings, Vol. 1258. ISBN 978-0-7354-0806-7. ISSN 0094-243X.
[MSMS 10 - Mossbauer Spectroscopy in Materials Science 2010. Liptovský Ján (SK), 31.01.2010-05.02.2010]
R&D Projects: GA MŠMT 1M0512
Institutional research plan: CEZ:AV0Z20410507; CEZ:AV0Z10100521
Keywords : nanotubes * Mossbauer * iron * carbides
Subject RIV: BM - Solid Matter Physics ; Magnetism

Phase composition of ~10 nm thick Fe film on the silicon substrate with 200 nm thick SiOx layer after annealing in vacuum and in H2+CH4 was investigated using Conversion Electron Mössbauer spectroscopy (CEMS) . CEMS spectra show that the original iron film was formed by Fe3+ phase. This phase is stable after the annealing in vacuum or in CH4+H2 below 500 °C but formation of phases with Fe2+ and Fe0 (γ-Fe and α-Fe) was observed after annealing at 500 °C and higher temperatures. Formation of fayalite (Fe2SiO4) occurred during vacuum annealing at 700 °C. SEM and CEMS study of the sample with grown multi-walled carbon nanotubes shows that the dominating part of iron atoms is present in Fe3C and Fe5C2 carbide phases. Besides their stoichiometric forms spectrum components which can be ascribed to the amorphous Fe5-xC2+x carbides, γ-Fe, and Fe3+ were observed there.
Permanent Link: http://hdl.handle.net/11104/0193498