Abstract
The liquid and amorphous structures of and GeTe alloys are characterized using combined density functional/molecular dynamics simulations. Te is threefold coordinated, in contrast with predictions of the “8- rule,” and Ge atoms (fourfold coordinated) show octahedral and tetrahedral bonding angles. Cubic local environment occurs in both materials, and GeTe shows a pronounced alternation of atomic types. Tetrahedral Ge coordination is more common in the eutectic , which comprises corner- and edge-sharing units surrounded by Te. There is no Te segregation, and the material resembles neither GeTe nor Te. The ubiquitous cavities (voids) have been overlooked in , where they comprise over 25% of the volume.
- Received 10 January 2008
DOI:https://doi.org/10.1103/PhysRevLett.100.205502
©2008 American Physical Society