Debdipto Acharya¹, Omar Abou El Kheir¹, Simone Perego¹, Davide Campi¹, Marco Bernasconi^1*

1 Department of Materials Science, University of Milano-Bicocca, Via R. Cozzi 55, 20125, Milan, Italy

* Corresponding authors emails: marco.bernasconi@unimib.it

DOI10.24435/materialscloud:xv-jk [version v2]

Publication date: Nov 07, 2024

How to cite this record

Debdipto Acharya, Omar Abou El Kheir, Simone Perego, Davide Campi, Marco Bernasconi, Atomistic simulations of the crystallization of amorphous GeTe nanoparticles, Materials Cloud Archive 2024.179 (2024), https://doi.org/10.24435/materialscloud:xv-jk

Description

The effect of dimensionality reduction on the crystallization kinetics of phase change materials is of relevance for the operation of ultrascaled memory devices. Therefore, the crystallization of amorphous nanoparticles (NPs) of the prototypical phase change compounds, GeTe and Ge₂Sb₂Te₅, has been addressed by several experimental works in recent years. In this work, we performed molecular dynamics simulations of the crystallization process of amorphous GeTe NPs with diameter in the range 3-6 nm (512-4096 atoms) by exploiting a machine-learned interatomic potential. We saw a few crystal nucleation events in the larger NPs but no crystallization in the smallest NP, 3 nm in diameter, in simulations lasting up to 80 ns in the temperature range 500-750 K. The analysis of the crystallization kinetics suggests that the nucleation rate per volume decreases with the NP size to an extent that prevents us from seeing crystallization in the smallest NP on our simulation time scale. This result is consistent with the large raise in crystallization temperature observed experimentally for NPs with diameters shorter than 3.5 nm.

Materials Cloud sections using this data

Files

File name	Size	Description
4096-NP-coord-600K-first-set.xyz MD5md5:d143e438d1ceeb7ecba56bf608122c15	316.4 MiB	Trajectory file of crystallization of 4096 atom nanoparticle at 600 K first set
4096-NP-coord-600K-first-set.ovito MD5md5:dac493700c13f605dd427b7f30eb01b9	340.0 KiB	Ovito session state to visualize the crystallization of 4096 atom nanoparticle at 600 K first set
4096-NP-coord-650K-first-set.xyz MD5md5:a36797a05990b5ffbdd024e2d8bf2bce	316.4 MiB	Trajectory file of crystallization of 4096 atom nanoparticle at 650 K first set
4096-NP-coord-650K-first-set.ovito MD5md5:c00f1e8e395faf8f15d5cd3786b78bb0	642.0 KiB	Ovito session state to visualize the crystallization of 4096 atom nanoparticle at 650 K first set
4096-NP-coord-700K-first-set.xyz MD5md5:2b78316d9b2e7758a7cd12b49b7f45cd	316.4 MiB	Trajectory file of crystallization of 4096 atom nanoparticle at 700 K first set
4096-NP-coord-700K-first-set.ovito MD5md5:8f89c852550ae41ecc0e88b43b13514c	944.1 KiB	Ovito session state to visualize the crystallization of 4096 atom nanoparticle at 700 K first set
4096-NP-coord-600K-second-set.xyz MD5md5:03d649eb9db7fba5a3255a568e602a4b	316.4 MiB	Trajectory file of crystallization of 4096 atom nanoparticle at 600 K second set
4096-NP-coord-600K-second-set.ovito MD5md5:52b86d7cd53549b426c645eb714169a9	345.1 KiB	Ovito session state to visualize the crystallization of 4096 atom nanoparticle at 600 K second set
4096-NP-coord-650K-second-set.xyz MD5md5:8976ffd7622211efbf6fe5e8a02c4223	316.4 MiB	Trajectory file of crystallization of 4096 atom nanoparticle at 650 K second set
4096-NP-coord-650K-second-set.ovito MD5md5:6f33814253a269c5ba5fdd8525c4dd0f	652.3 KiB	Ovito session state to visualize the crystallization of 4096 atom nanoparticle at 650 K second set
4096-NP-coord-700K-second-set.xyz MD5md5:14237a39b35212e91cd67b0782ca5b77	316.4 MiB	Trajectory file of crystallization of 4096 atom nanoparticle at 700 K second set
4096-NP-coord-700K-second-set.ovito MD5md5:3c145a34bdc87756ca3dedbe178a8591	959.5 KiB	Ovito session state to visualize the crystallization of 4096 atom nanoparticle at 700 K second set
1728-NP-coord-600K-first-set.xyz MD5md5:8eb2c81c70b177c7a6cfc871f26dd15b	222.5 MiB	Trajectory file of crystallization of 1728 atom nanoparticle at 600 K
1728-NP-coord-600K-first-set.ovito MD5md5:6970227a581994ca4469a45e90843d45	542.6 KiB	Ovito session state to visualize the crystallization of 1728 atom nanoparticle at 600 K
1728-NP-coord-650K-first-set.xyz MD5md5:4b954aede92ce3bf9949ee93dd4af71e	213.6 MiB	Trajectory file of crystallization of 1728 atom nanoparticle at 650 K
1728-NP-coord-650K-first-set.ovito MD5md5:552670a7cc3f9996380f45dd60a2b775	1.0 MiB	Ovito session state to visualize the crystallization of 1728 atom nanoparticle at 650 K
512-NP-coord-600K-first-set.xyz MD5md5:b8da52c5940595d2f172dbb22f42c230	84.4 MiB	Trajectory file of crystallization of 512 atom nanoparticle at 600 K
512-NP-coord-600K-first-set.ovito MD5md5:1b020a35347da81297b32a0c4c49619e	674.2 KiB	Ovito session state to visualize the crystallization of 512 atom nanoparticle at 600 K
4096-bulk-coord-600K-first-set.xyz MD5md5:f3d7b3939e191d0dcc002445864a2581	421.9 MiB	Trajectory file of crystallization of 4096 atom bulk at 600 K first set
4096-bulk-coord-600K-first-set.ovito MD5md5:5f4de20838fb6e50a448d214e39140c3	871.5 KiB	Ovito session state to visualize the crystallization of 4096 atom bulk at 600 K first set
4096-bulk-coord-650K-first-set.xyz MD5md5:bdadf61eaea256efd2a33069100f6ad2	421.9 MiB	Trajectory file of crystallization of 4096 atom bulk at 650 K first set
4096-bulk-coord-650K-first-set.ovito MD5md5:37f461876ab37ef54543349a55ef7c92	871.5 KiB	Ovito session state to visualize the crystallization of 4096 atom bulk at 650 K first set
4096-bulk-coord-600K-second-set.xyz MD5md5:f3d7b3939e191d0dcc002445864a2581	421.9 MiB	Trajectory file of crystallization of 4096 atom bulk at 650 K second set
4096-bulk-coord-600K-second-set.ovito MD5md5:2416cf5a0a000bf272d51d4cc6685249	461.8 KiB	Ovito session state to visualize the crystallization of 4096 atom bulk at 600 K second set
539-atom-NP-DFT-optimized.xyz MD5md5:b55bc655704b244aff360719d836f8da	25.1 KiB	539 atom nanoparticle DFT optimized
README.pdf MD5md5:d4be1b5929d1df42b466a113850bd9e8	175.4 KiB	Instructions to open an ovito state file

License

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External references

Keywords

Neural Network Potential Crystallization Phase Change Materials GeTe molecular dynamics simulation Neuromophic Computing