Structural investigation of small Cu clusters obtained by ion-implantation in amorphous silica

In this paper we present an EXAFS study on Cu clusters obtained by ion-implantation in amorphous silica substrates. As-implanted and 700 degrees C annealed samples were analyzed both at liquid nitrogen temperature and room temperature in order to determine the structural parameters. Evidence of a lattice contraction beyond the anharmonic correction were found in the tiniest particles, as well as a clear contribution of static disorder to the total Debye-Waller factor. No change of the Debye temperature due to overpressure was found in agreement with the calculations.