EXAFS study of nanocrystalline cobalt

An EXAFS study of the local environment of nanocrystalline cobalt is presented. In order to determine the pair correlation function (PCF) by solving the integral equation we applied a modified regularization algorithm. For nano-Co we obtain an enhanced reduction of the first coordination number (N = 6.4 atoms). The difference of nano- and poly-EXAFS (with some weight coefficient) spectra yields a weak signal, originated from the atoms in the boundary layer of crystalline grains (not only on the surface of grains). The grain boundary component PCF indicates a small symmetric peak with interatomic distance r = 2.52 Å and coordination number N = 4 atoms. The obtained results are discussed.