Nanoscale decomposition of Nb–Ru–O

Abstract A correlative theoretical and experimental methodology has been employed to explore the decomposition of amorphous Nb–Ru–O at elevated temperatures. Density functional theory based molecular dynamics simulations reveal that amorphous Nb–Ru–O is structurally modified within 10 ps at 800 K giving rise to an increase in the planar metal – oxygen and metal – metal population and hence formation of large clusters, which signifies atomic segregation. The driving force for this atomic segregation process is 0.5 eV/atom. This is validated by diffraction experiments and transmission electron microscopy of sputter-synthesized Nb–Ru–O thin films. Room temperature samples are amorphous, while at 800 K nanoscale rutile RuO 2 grains, self-organized in an amorphous Nb–O matrix, are observed, which is consistent with our theoretical predictions. This amorphous/crystalline interplay may be of importance for next generation of thermoelectric devices.