Capillary effect was used to fill double wall carbon nanotubes ( DWCNT) with iron. The samples are characterized by Mossbauer and Raman spectroscopies, TEM, SAED, and magnetization. The experimental results indicate the presence of alpha-Fe nanowires inside the DWCNTs. The samples are ferromagnetic at room temperature. There are three striking results due to the confinement effects on the physical behavior of alpha-Fe: the hyperfine fields increase, the Debye temperature decreases and Raman modes are observed. (c) 2008 Elsevier B. V. All rights reserved.