The first stages in the growth of a nickel deposit on to the (100) face of TiO 2 was investigated using mainly Auger electron spectroscopy (AES) and secondary ion mass spectrometry (SIMS). Auger intensities of both adsorbate (Ni) and substrate (Ti, O) were followed versus deposition time. A layer-by-layer growth of three nickel layers is obtained followed by a nucleation stage. The attenuation coefficients for adsorbate and substrate Auger peaks through a monolayer of adsorbate are calculated. In dynamic SIMS experiments secondary ionic intensities of the deposit and of the substrate were measured during sputtering. By using the sequential layer sputtering (SLS) model for the sputtering process, the morphology of the deposit obtained by AES is confirmed.