Isothermal oxidation kinetics of nanocrystalline and coarse grained nickel: Experimental results and theoretical approach

►The weight gain (w) of nanocrystalline Ni was higher than the coarse grained Ni. ►A linear Arrhenius plot was observed only for kp values corresponding to a given w. ►A value ~ 108 kJ/mol was derived for activation energy for NiO growth on both sets. ►The established analytical model agrees well with experimental results. ►Activation energy of grain boundary diffusion was determined using fitting parameter.