Effect of tellurium concentration on the structural and vibrational properties of phase-change Ge-Sb-Te liquids

Abstract

The structural properties of several compositions of Ge-Sb-Te liquids are studied from a combination of neutron diffraction and density functional-based molecular dynamics. We investigate structural properties including structure factors, pair distribution functions, angular distributions, coordination numbers, neighbor distributions, and compare our results with experimental findings. Most noticeable is the excellent agreement found in the reproduction of the structure in real and reciprocal spaces, resulting from the incorporation of dispersion forces in the simulation. The vibrational density of states is also measured from inelastic neutron scattering for different compositions and compared to the simulated counterpart, which exhibits an excellent agreement at low frequency.