Grain growth of CuO nanocrystal activated by high energy ball milling

X-ray Diffraction (XRD), small-angle X-ray scattering, scanning electron microscopy and energy dispersive X-ray Analysis were used to investigate the effect of controlled high energy ball milling (HEBM) on the average volume weighted crystallite size, 〈 D〉 V and weighted average microstrain, 〈 ε〉, of nanostructures of CuO prepared by solid state reaction. The starting material, S 0, consists of almost strain free nanocrystals of monoclinic CuO with 〈 D〉 V ≈ 20nm , as determined by XRD data Rietveld analysis. It was found that after an initial decrease of 〈 D〉 V and increase of 〈 ε〉, the values of these parameters go through a steady-state stage followed by an increase of an order of magnitude in 〈 D〉 after a period of only 120 m of HEBM. According to the results here presented, the presence of small amounts of contaminants in the starting material can have an influence on the kinetics of crystal growth in HEBM CuO.