The geometrical structure of a low coverage Ni species on an alpha-Al2O3 (0 0 0 1) single crystal surface has been studied using a polarization-dependent total reflection fluorescence extended X-ray absorption fine structure (PTRF-EXAFS) spectroscopy to reveal the bonding feature between the metal and the oxide surface. The Ni species on the alpha-Al2O3 (0 0 0 1) surface is atomically dispersed with a Ni-O distance at 0.198 +/- 0.003 nm. The adsorption site is determined to be a threefold oxygen site on top of a deep Al atom accompanied with a relaxation of the nearest neighbor oxygen atoms. (C) 2003 Elsevier B.V. All rights reserved.