Elemental antimony has been recently proposed as a promising material for phase change memories with improved performances with respect to the most used ternary chalcogenide alloys. The compositional simplification prevents reliability problems due to demixing of the alloy during memory operation. This is made possible by the dramatic stabilization of the amorphous phase once Sb is confined in an ultrathin film 3-5 nm thick. In this work, we shed light on the microscopic origin of this effect by means of large scale molecular dynamics simulations based on an interatomic potential generated with a machine learning technique. The simulations suggest that the dramatic reduction of the crystal growth velocity in the film with respect to the bulk is due to the effect of nanoconfinement on the fast beta relaxation dynamics while the slow alpha relaxation is essentially unaffected.

Dragoni, D., Behler, J., Bernasconi, M. (2021). Mechanism of amorphous phase stabilization in ultrathin films of monoatomic phase change material. NANOSCALE, 13(38), 16146-16155 [10.1039/d1nr03432d].

Mechanism of amorphous phase stabilization in ultrathin films of monoatomic phase change material

Dragoni, Daniele;Bernasconi, Marco
2021

Abstract

Elemental antimony has been recently proposed as a promising material for phase change memories with improved performances with respect to the most used ternary chalcogenide alloys. The compositional simplification prevents reliability problems due to demixing of the alloy during memory operation. This is made possible by the dramatic stabilization of the amorphous phase once Sb is confined in an ultrathin film 3-5 nm thick. In this work, we shed light on the microscopic origin of this effect by means of large scale molecular dynamics simulations based on an interatomic potential generated with a machine learning technique. The simulations suggest that the dramatic reduction of the crystal growth velocity in the film with respect to the bulk is due to the effect of nanoconfinement on the fast beta relaxation dynamics while the slow alpha relaxation is essentially unaffected.
Articolo in rivista - Articolo scientifico
phase change materials, non-volatile memory; neural network; molecular dynamics
English
20-set-2021
2021
13
38
16146
16155
open
Dragoni, D., Behler, J., Bernasconi, M. (2021). Mechanism of amorphous phase stabilization in ultrathin films of monoatomic phase change material. NANOSCALE, 13(38), 16146-16155 [10.1039/d1nr03432d].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/330239
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