Free-standing urethane/urea elastomer films undoped and doped with ferro-nano-particles C. Sena, M.H. Godinho, P.J. Sebastião, D. Sousa and A.M. Figueiredo Neto Eur. Phys. J. E, 34 1 (2011) 8 Published online: 24 January 2011 DOI: 10.1140/epje/i2011-11009-8