Electron Energy-Loss Spectroscopy Study of the Change in the Free-Electron Density in Thin Superconducting NbN Films under Ion-Beam Irradiation

• Published in: Crystallography reports 2018-03, Vol.63 (2), p.241-244
• Main Authors: Prikhodko, K. E., Dementyeva, M. M., Gurovich, B. A., Komarov, D. A., Kutuzov, L. V.
• Format: Article
• Language: English
• Subjects: ATOMS; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CROSS SECTIONS; Crystallography and Scattering Methods; ELECTRICAL PROPERTIES; ELECTRON DENSITY; Electron energy; Electron energy loss spectroscopy; Electrons; ENERGY-LOSS SPECTROSCOPY; ION BEAMS; IRRADIATION; Niobium nitride; NIOBIUM NITRIDES; NITROGEN; Nitrogen atoms; OXYGEN; Oxygen atoms; OXYGEN IONS; Physics; Physics and Astronomy; PLASMONS; Radiation dosage; RADIATION DOSES; Radiation effects; Spectroscopic analysis; Spectrum analysis; SUPERCONDUCTING FILMS; Superconductivity; Surface and Thin Films; Thin films
• ISSN: 1063-7745; 1562-689X
• DOI: 10.1134/S1063774518020219

The change in the free-electron density in ultrathin (5 nm) superconducting NbN films in the initial state and after irradiation by O + ions to doses of (0.1–0.9) × 10 17 cm –2 has been studied by electron energy-loss spectroscopy (EELS). The analysis has been performed on cross section samples prepared by the focused ion beam method, using plasmon oscillations with energies up to 50 eV. The radiation-induced replacement of nitrogen atoms with oxygen atoms in niobium nitride is found to change the electrical properties of the material, which leads to a decrease in the free-electron density with an increase in the irradiation dose.