Magnetic and vibrational properties of small chromium clusters on the Cu(111) surface

The structure and magnetic properties of small Cr clusters, Cr-3 and Cr-4, adsorbed on the Cu(111) surface have been investigated using density functional theory (DFT) calculations and their vibrational properties have been studied within calculations based on tight-binding second moment approximation interatomic interaction potentials (TBSMA). It has been shown that the magnetic ordering in the Cr clusters significantly affects their crystal structure and symmetry, which influences the vibrational modes of the clusters and nearest neighbor copper atoms. In turn, these modes select potentially possible structures of Cr-3 and Cr-4, prohibiting the lowest total energy cluster structure as dynamically unstable.