α-Fe nanopowder synthesised in low-pressure microwave plasma and studied by Mössbauer spectroscopy

0375153 - ÚFM 2012 RIV GB eng J - Článek v odborném periodiku
David, Bohumil - Pizúrová, Naděžda - Schneeweiss, Oldřich - Šantavá, Eva - Jašek, O. - Kudrle, V.
α-Fe nanopowder synthesised in low-pressure microwave plasma and studied by Mössbauer spectroscopy.
Journal of Physics: Conference Series. Roč. 303, č. 1 (2011), 012090. ISSN 1742-6588. E-ISSN 1742-6596.
[Joint European Magnetic Symposia, JEMS 2010. Krakow, 23.08.2010-28.08.2010]
Grant CEP: GA MŠMT 1M0512; GA ČR GA202/08/0178
Výzkumný záměr: CEZ:AV0Z10100520; CEZ:AV0Z20410507
Klíčová slova: α-Fe * nanočástice * mikrovlnné plazma * Mössbauerova spektroskopie
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
http://iopscience.iop.org/1742-6596/303/1/012090/pdf/1742-6596_303_1_012090.pdf

An iron-based nanocomposite has been prepared by the microwave plasma method: Fe(CO)5 vapour was introduced into an argon discharge at ~1 kPa. The synthesised nanopowder was passivated in situ with a mixture of Ar and air. The as-prepared nanopowder was characterised by XRD, TEM, Raman and Mössbauer spectroscopies. In the XRD pattern of the nanopowder the α-Fe (d_XRD = 14 nm, 76 wt.%) and Fe(3)O(4) (d_XRD = 3 nm, 24 wt.%) phases were identified only. α-Fe cores covered with oxide shells were observed under TEM. A huge increase of Mössbauer absorption was observed after the sample was cooled down to 5 K. The results of magnetic and thermal properties studies at low and high temperature are presented. The heat capacity of the sample exhibited an unexpectedly high value of 599 J/kg/K.
Trvalý link: http://hdl.handle.net/11104/0207888