This work concerns the deposition of Sb on the (110) clean surface of silver. Two structured phases have been observed: an Ag(110)(4 x 1)-Sb, with a Sb coverage of about 1.0 ML and an Ag(110)c(2 x 2)-Sb, with half the coverage of the first one. The structural determination of the Ag(110)c(2 x 2)-Sb phase has been performed by a standard LEED analysis and the results obtained indicate the presence of substitutional Sb atoms in the first atomic layer. The presence of the Sb substitutional atoms promotes an expansion in the first interlayer distance without any change in the surface thermal vibrational behaviour. Based on results obtained by this study and previously published ones, the substitutional site seems to be most energetically favourable for Sb atoms, in any of the low index surfaces of silver. (C) 2004 Elsevier B.V. All rights reserved.57241700337346