Iron Nanoparticle Generation by He+ Ion Bombardment

Abstract

The effect of (1-4 keV) energetic He+ ion irradiation over clean pyrite substrates was studied by means of a multitechnique approach, including scanning tunneling microscopy (STM), scanning tunneling spectroscopy (STS), X-ray photoelectron spectroscopy (XPS), ion scattering spectrometry (ISS), and Auger electron spectroscopy (AES). Using these different techniques, we were able to characterize with a great amount of detail the nanostructuring process. Thus, meanwhile through STM we found that upon ion irradiation the surface becomes structured with particles in the nanometer range; through XPS and ISS we determined that these particles are mostly composed of metallic iron. Through STM we also found that surface roughness increases with ion energies, and using oxygen as a marker, we characterize through AES the in-depth iron distribution. Finally, through STS we found changes in the pyrite band gap induced by ion bombardment.