Hyperfine Interact DOI 10.1007/s10751-011-0467-5 Iron-containing microphases in multiwalled carbon nanotubes Alexey V. Sobolev · Nikolai B. Cherkasov · Igor A. Presniakov · Serguei V. Savilov © Springer Science+Business Media B.V. 2011 Abstract The phase composition of carbon nanotubes (CNTs) with encapsulated iron atoms was examined by 57 Fe Mössbauer spectroscopy. It was shown that iron atoms were stabilized in thermodynamically stable iron carbide and oxide phases and phases that are not usual under synthesis conditions (γ-Fe and γ-Fe 2 O 3 ). Keywords Multiwalled carbon nanotubes · Mössbauer spectroscopy 1 Introduction The interest of researchers specializing in various areas of material sciences in carbon nanotubes (CNT) has increased in recent years primarily because of a wide range of their application in different technologies. A fairly high surface area of these materials and their thermal stability allow nanotubes to be used as carriers of various catalysts, and the possibility of chemical modification of their surfaces enables to create new hybrid materials [1]. 2 Experimental The synthesis of iron-containing multiwalled carbon nanotubes was performed on an injection unit following the procedure described in [2]. A. V. Sobolev (B ) · N. B. Cherkasov · I. A. Presniakov · S. V. Savilov Chemistry Department, Lomonosov Moscow State University, Moscow, 119991, Russia e-mail: salex12@rambler.ru URL: http://www.chem.msu.ru/rus/radio/03.html