Investigating Local Structure Of Ion-Implanted (Ni2+) And Thermally Annealed Rock Salt Coo Film By Exafs Simulation Using Evolutionary Algorithm

The CoO film deposited on the surface of F-doped SnO2 (FTO) conductive glass was prepared via drop casting technique. The effects of Ni2+-ion implantation at 700 keV energy and postannealing in vacuum at 450 degrees C temperature on the local structure of the CoO film was systematically explored. The XAFS study revealed the substitution of octahedral Co2+ by Ni2+ ion (Co1-xNixO) as a result of ion implantation. The existence of defects in local structure around the octahedral Co for the Co1-xNixO film after thermal annealing in vacuum was demonstrated by the theoretical EXAFS [chi(k)] simulation via evolutionary algorithm implemented in reverse Monte Carlo method in rationale with EXAFS fitting. Nevertheless, the cubic rock salt structure for the Co1-xNixO was conserved, corroborated through XRD patterns, suggesting a remarkable candidate for application as an electrocatalyst in fuel cells.