May 26, 2010 Wednesday 15:30
Sondan Durukanoğlu Feyiz, İTÜ
Vibrational Behavior of Metal Nanowires under Tensile Stress

Abstract: We have investigated the vibrational density of states (VDOS) of an ultrathin Cu nanowire with $<100>$ axial orientation and considered the effect of axial strain. The VDOS are calculated using a real space Green's function approach with the force constant matrices extracted from interaction potential based on the embedded atom method. Results for the vibrational density of states of a strain-free nanowire show quite distinctive characteristics compared to that of a bulk atom, the most striking feature of which is the existence of high frequency modes above the top of the bulk spectrum. Through decomposition of VDOS into local atoms we also exhibit that while the anomalous increase in low frequency density of states is mainly due to the corner atoms, the enhancement in high frequency modes is primarily moderated by core atoms.