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DS: Fachverband Dünne Schichten
DS 33: Focus session: Resistive Switching by Redox and Phase Change Phenomena IV (Kinetic in oxides and phase change)
DS 33.5: Talk
Wednesday, April 2, 2014, 17:45–18:00, CHE 89
Ab initio molecular dynamics simulations of crystallization of AIST — •Wei Zhang1, Ider Ronneberger1, Peter Zalden2, 3, Martin Salinga2, Matthias Wuttig2, 4, and Riccardo Mazzarello1, 4 — 1Institute for Theoretical Solid State Physics, RWTH Aachen University, D-52056 Aachen, Germany — 2I. Physikalisches Institut (IA), RWTH Aachen University, D-52056 Aachen, Germany — 3School of Medicine, Stanford University, Stanford, CA 94305, USA — 4JARA, RWTH Aachen University, D-52056 Aachen, Germany
Chalcogenide phase change materials (PCMs) are of great interest for both industrial applications and fundamental research, owing to their remarkable properties. The ultrafast switching capability between amorphous and crystalline state together with the pronounced property contrast between the two states has led to applications in optical data storage as well as electronic non-volatile memories. In this work, we investigate the fast crystallization process of Ag, In-doped Sb2Te (AIST) using ab initio molecular dynamics (AIMD). We find a good match between the computed growth velocities and recent time-resolved reflectivity measurements at high temperature (550K-600K), while large deviations are present at lower temperature. We suggest that the large deviations are due to the different quenching rates and the high fragility of AIST in the supercooled phase. Besides, we identify the role of impurities (Ag/In) in the crystallization process of AIST at high temperature.