Carbon ion implantation into pure aluminium at low fluences

This work presents selected results from carbon ion implantation into pure Al matrix. The carbon ions were implanted with an ion energy of 25 keV and fluences of 1×1021 and 2×1021 C+/m2 at room temperature (RT) and elevated temperature of 400 °C. Elastic recoil detection analysis (ERDA), grazing incidence X-ray diffraction analysis (GIXRD), Raman spectroscopy and high resolution electron microscopy (HRTEM) show the formation of embedded Al4C3 precipitates with carbon concentrations below its stoichiometric level. At RT ion implantation, the Al4C3 precipitates have an average grain size in the order of 2-4 nm. For carbon ion implantation at 400 °C, the precipitates grow up to approximately 20 nm in diameter and are randomly distributed in the implanted region. The carbon excess, not bound in the Al4C3 precipitates, forms highly disordered C-C clusters of approximately 0.2-0.4 nm in size. Implantation at a temperature of 400 °C reduces drastically the carbon clusters content due to the growth of the Al4C3 precipitates.