Interfacial phase-change memory (iPCM) based on layer-structured Ge-Sb-Te crystals has been recently proposed, offering an energy-efficient implementation of nonvolatile memory cells and supplementing the development of Ge-Sb-Te-based phase-change random access memories (PRAMs). Although the working principle of iPCM is still under debate, it is believed that layer-switching plays a role in the switching process between the low-resistance and high-resistance states of iPCM memory cells. However, the role of Ge in forming swapped bilayers—the key elements for layer-switching—is not yet clarified. This work manages to achieve layer-switching in Sb2Te3 thin films by manipulating the formation of bilayer defects using magnetron sputtering and post-thermal annealing. By combining scanning transmission electron microscopy (STEM) experiments with density functional theory (DFT) calculations, the essential role of Sb-Te intermixing is elucidated in stabilizing swapped bilayers at a low energy cost. In situ STEM experiments provide a real-time and real-space view of dynamical reconfiguration of van der Waals-like gaps in Sb2Te3 thin films under electron-beam irradiation. The results show that the Ge atoms are not necessary for the formation and motion of swapped bilayers, providing atomic insights on the layer-switching mechanism in layer-structured binary and ternary group V- and IV–V-tellurides for memory applications.
Layer-switching mechanisms in Sb2Te3 / Wang, J. -J.; Wang, J.; Xu, Y.; Xin, T.; Song, Z.; Pohlmann, M.; Kaminski, M.; Lu, L.; Du, H.; Jia, C. -L.; Mazzarello, R.; Wuttig, M.; Zhang, W.. - In: PHYSICA STATUS SOLIDI. RAPID RESEARCH LETTERS. - ISSN 1862-6254. - 13:10(2019), p. 1900320.
|Titolo:||Layer-switching mechanisms in Sb2Te3|
|Data di pubblicazione:||2019|
|Citazione:||Layer-switching mechanisms in Sb2Te3 / Wang, J. -J.; Wang, J.; Xu, Y.; Xin, T.; Song, Z.; Pohlmann, M.; Kaminski, M.; Lu, L.; Du, H.; Jia, C. -L.; Mazzarello, R.; Wuttig, M.; Zhang, W.. - In: PHYSICA STATUS SOLIDI. RAPID RESEARCH LETTERS. - ISSN 1862-6254. - 13:10(2019), p. 1900320.|
|Appartiene alla tipologia:||01a Articolo in rivista|