We investigated the structural, electronic and vibrational properties of amorphous and cubic Ge2Sb2Te5 doped with N at 4.2at.% by means of large scale abinitio 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.
Caravati, S., Colleoni, D., Mazzarello, R., Kühne, T., Krack, M., Bernasconi, M., et al. (2011). First-principles study of nitrogen doping in cubic and amorphous Ge2Sb2Te5. JOURNAL OF PHYSICS. CONDENSED MATTER, 23(26) [10.1088/0953-8984/23/26/265801].
First-principles study of nitrogen doping in cubic and amorphous Ge2Sb2Te5
BERNASCONI, MARCO;
2011
Abstract
We investigated the structural, electronic and vibrational properties of amorphous and cubic Ge2Sb2Te5 doped with N at 4.2at.% by means of large scale abinitio 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.