Unconventional melting behavior and dynamical properties of Cr 2 Ge 2 Te 6 phase‐change material

Abstract Cr 2 Ge 2 Te 6 (CrGT) is a promising candidate for phase‐change memory applications. In amorphous CrGT, Cr atoms form non‐defective octahedral motifs with Te atoms, and the abundance of octahedra is regarded as the key structural factor in limiting the resistance drift of amorphous CrGT. However, the stage at which these octahedra emerge during melt‐quench amorphization remains unclear. Here, we present ab initio molecular dynamics simulations to model melting of layered crystalline CrGT and to investigate the dynamic properties of liquid CrGT. Upon heating, Ge atoms are observed to leave their lattice sites earlier than Cr and Te atoms, diffusing into the van der Waals gap and initiating the collapse of the layered structure. The Cr[Te 6 ] octahedra are more robust, maintaining their structural pattern up to 1400 K despite continuous rupture and re‐formation of Cr–Te bonds. In supercooled liquid CrGT at 550 K, most Cr‐centered octahedra remain intact, enabling rapid crystallization of CrGT in memory devices. Together, these results provide a local‐motif‐based chemical picture in which robust transition‐metal chalcogenide octahedra preserve structural fragments, whereas more labile Ge‐centered units accommodate phase switching.