The growth of Fe on the c(2 x 2) N/Cu(1 0 0) surface was studied with X-ray absorption fine structure (XAFS) assisted by LEED. Previous STM work had shown that atomic N on Cu(1 0 0) forms periodic arrays of c(2 x 2) N islands with a size of about 5 nm x 5 nm channelling the growth of Fe onto the clean Cu areas. From XAFS multishell analysis we describe the growth in terms of face-centred cubic (fee) phasewith strong lattice distortion, deviation from layer by layer growth, and presence of complex surface phases, some with different geometry. The differences between the Fe growth mode on the clean and on the N-saturated Cu(1 0 0) surface are explained in terms of Fe-N atom interactions, and we obtained the adsorption geometry of Fe on the N-saturated surface. (C) 2003 Elsevier Science B.V. All rights reserved.