The reduction of the active cell size to the nanoscale is crucial for the improvement of the phase change memory devices (PCM) based on Ge-Sb-Te (GST) alloys. The self-assembly of Au catalyzed Ge1Sb2Te4 (GST-124) nanowires (NWs) has been achieved by metal organic chemical vapor deposition. The atomic arrangement of the NWs has been investigated and the stacking sequence has been identified, by combining the direct observation by High Angle Annular Dark Field (HAADF) imaging and simulations. It has been assessed that Ge and Sb atoms can randomly occupy the same sites in the crystal lattice, despite the adverse predictions of the theoretical models elaborated for the bulk material.
Determination of the atomic stacking sequence of Ge-Sb-Te nanowires by HAADF STEM
Laura Lazzarini;Enzo Rotunno;Vincenzo Grillo;Massimo Longo
2012
Abstract
The reduction of the active cell size to the nanoscale is crucial for the improvement of the phase change memory devices (PCM) based on Ge-Sb-Te (GST) alloys. The self-assembly of Au catalyzed Ge1Sb2Te4 (GST-124) nanowires (NWs) has been achieved by metal organic chemical vapor deposition. The atomic arrangement of the NWs has been investigated and the stacking sequence has been identified, by combining the direct observation by High Angle Annular Dark Field (HAADF) imaging and simulations. It has been assessed that Ge and Sb atoms can randomly occupy the same sites in the crystal lattice, despite the adverse predictions of the theoretical models elaborated for the bulk material.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
