Synthesis, structural and physical properties of δ'-FeSe1-x M. de Souza, A.-A. Haghighirad, U. Tutsch, W. Assmus and M. Lang Eur. Phys. J. B, 77 1 (2010) 101-107 Published online: 13 September 2010 DOI: 10.1140/epjb/e2010-00254-7