title: First-principles study of nitrogen doping in cubic and amorphous Ge2Sb2Te5.
abstract: We investigated the structural, electronic and vibrational properties of amorphous and cubic Ge(2)Sb(2)Te(5) doped with N at 4.2 at.% by means of large scale ab initio simulations. Nitrogen can be incorporated in molecular form in both the crystalline and amorphous phases at a moderate energy cost. In contrast, insertion of N in the atomic form is very energetically costly in the crystalline phase, though it is still possible in the amorphous phase. These results support the suggestion that N segregates at the grain boundaries during the crystallization of the amorphous phase, resulting in a reduction in size of the crystalline grains and an increased crystallization temperature.
authors.affiliation: Computational Science, Department of Chemistry and Applied Biosciences, ETH Zurich, USI Campus, Via Giuseppe Buffi 13, CH-6900 Lugano, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Caravati
authors.forename: D
authors.initials: D
authors.lastname: Colleoni
authors.forename: R
authors.initials: R
authors.lastname: Mazzarello
authors.forename: T D
authors.initials: TD
authors.lastname: Kühne
authors.forename: M
authors.initials: M
authors.lastname: Krack
authors.forename: M
authors.initials: M
authors.lastname: Bernasconi
authors.forename: M
authors.initials: M
authors.lastname: Parrinello