Time and temperature dependencies of nickel silicide axial growth in Si nanowires (SiNWs) were studied for a temperature range of 300-440 degrees C and nanowire diameters of 30-60 nm. A square root time dependence of the total suicide intrusion length was found. It was concluded that formation of nickel suicides was controlled by diffusion of Ni along the nickel silicide surface or the nickel silicide/SiO2 interface to the Si/suicide interface. Subsequent annealing cycles at different temperatures revealed Arrhenius-type behavior for the increase of the intrusion length square (Delta L-n(2)) with an activation energy of 1.45 +/- 0.11 eV. Additional and significant silicide growth during heating and cooling of the wire was taken into account by using self consistent iteration procedure for Delta L-n(2) calculations. The resulted activation energy agrees well with previous results. Published by Elsevier Ltd.