Electronic energy loss (S _e) sensitivity of electrochemically synthesized free-standing Cu nanowires irradiated by 120 MeV high energy ion beam of different atomic mass

Ion beam irradiation is a technique to tune the properties of copper nanowires for various potential applications. Copper nanowires prepared by template-assisted electrochemical deposition have been irradiated with two different ions ₁₆S³² and ₇₉Au¹⁹⁷ (Energy = 120 MeV and Charge state = 9 +), respectively, at different fluences of 1 × 10¹¹, 5 × 10¹¹, 1 × 10¹² and 5 × 10¹² ions/cm², to study the role of S_e in modifying properties of the nanowires. The rate of energy deposited by incident ion in a material medium is a linear function of atomic number of the incident ion as governed by Bethe-Bloch formula, thus, the modifications produced by both ions in the same host matrix would be different. Scanning Electron Microscopy graphs revealed that nanowires kept their integrity on irradiation with both ions and at all irradiation fluences. The effect of irradiation on the structural properties were studied using X-ray diffraction measurements. Upon irradiation, peak intensity changed significantly due to irradiation-induced defects and was quantitatively calculated using Harris formula. The crystallite size, surface morphology, dislocation density, strengthening coefficient, strain, stress and optical properties were analyzed before and after irradiation. The crystallite size of the nanowires increases with increasing ion fluence and also the strain and dislocation density value decreases for nanowires irradiated with sulphur (9+) ions and opposite trend was observed for nanowires irradiated with Gold (9+) ions. The resistivity data obtained from the I–V characteristics curve was defined by the combined Fuchs–Sondheimer model and Mayadas–Shatzkes model with a surface specularity coefficient of 0.52. Graphic abstract: [Figure not available: see fulltext.].