Particle irradiation and electron work function: Fe single crystal bombarded with Ar⁺ ions

Accelerated Ar⁺ ions of 30 keV energy were used to mimic the effect of fast neutrons on Fe single crystal. Both Monte-Carlo calculations and X-ray Photoelectron Spectroscopy (XPS) measurements indicated that the fast ions did not alter the surface causing damage only at several nm depth. The change in the electrode potential, characteristic also to corrosion processes, was determined by the Kelvin method of work function measurement in order to avoid any post-irradiation process. Irradiation with fluences between 5×10¹⁴ and 6×10¹⁵ cm⁻² decreased the electrode potential of the sample by about 60 mV in qualitative agreement with earlier results about the work functions of Fe single crystal and polycrystalline sample. Thus ion irradiation turns the interior of the single crystal into a disordered, polycrystalline substance increasing the crystal's readiness to be corroded. - Highlights: • Fe single crystal was irradiated by Ar⁺ ions. • Work function was measured. • Irradiation caused an about 60 mV decrease of the electrode potential. • Thus irradiation was shown to increase corrosion hazard.