Structural studies of nucleation and growth of Cu and Fe nanoparticles using XAFS simulation

Theoretical models for copper and iron at different cluster sizes have studied by XANES and EXAFS using FEFF9 code, which does both XANES as well as EXAFS calculations in an advanced manner. It was shown that the size of the clusters affects the characteristics of the structure for both Cu and Fe clusters where the structural parameters are affected by the variation of the cluster sizes. XANES results indicated divergence for clusters in sizes close to the lattice parameters for both Cu and Fe. Theoretical XANES and density of states calculations provided detailed insights into the origin of the XANES features for copper and iron. The absorption edge of Cu clusters almost completely reproduces the unoccupied band of p electrons.