We investigated the structural, electronic and vibrational properties of amorphous and cubic Ge2Sb2Te5 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.
First-principles study of nitrogen doping in cubic and amorphous Ge2Sb2Te5 / Caravati, S; Colleoni, D; Mazzarello, R; Kuhne, Td; Krack, M; Bernasconi, M; Parrinello, M. - In: JOURNAL OF PHYSICS. CONDENSED MATTER. - ISSN 0953-8984. - 23:26(2011). [10.1088/0953-8984/23/26/265801]
First-principles study of nitrogen doping in cubic and amorphous Ge2Sb2Te5
Mazzarello R;
2011
Abstract
We investigated the structural, electronic and vibrational properties of amorphous and cubic Ge2Sb2Te5 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.