Francesco Tavanti^1*, Behnood Dianat^2*, Alessandra Catellani^1*, Arrigo Calzolari^1*

1 CNR NANO, Via Campi 213, Modena, Italy

2 INTERMECH, University of Modena and Reggio Emilia, Via Pietro Vivarelli 10, Modena, Italy

* Corresponding authors emails: francesco.tavanti@nano.cnr.it, behnood.dianat@unimore.it, alessandra.catellani@nano.cnr.it, arrigo.calzolari@nano.cnr.it

DOI10.24435/materialscloud:ef-va [version v1]

Publication date: Jan 18, 2022

How to cite this record

Francesco Tavanti, Behnood Dianat, Alessandra Catellani, Arrigo Calzolari, Hierarchical short- and medium-range order structures in amorphous Ge_x Se_1–x for selectors applications, Materials Cloud Archive 2022.7 (2022), https://doi.org/10.24435/materialscloud:ef-va

Description

In the upcoming process to overcome the limitations of the standard von Neumann architecture, synaptic electronics is gaining a primary role for the development of in-memory computing. In this field, Ge-based compounds have been proposed as switching materials for nonvolatile memory devices and for selectors. By employing the classical molecular dynamics, we study the structural features of both the liquid states at 1500 K and the amorphous phase at 300 K of Ge-rich and Se-rich chalcogenides binary Ge_x Se_1–x systems in the range 0.4 ≤ x ≤ 0.6. The simulations rely on a model of interatomic potentials where ions interact through steric repulsion, as well as Coulomb and charge–dipole interactions given by the large electronic polarizability of Se ions. Our results indicate the formation of temperature-dependent hierarchical structures with short-range local orders and medium-range structures, which vary with the Ge content. Our work demonstrates that nanosecond-long simulations, not accessible via ab initio techniques, are required to obtain a realistic amorphous phase from the melt. Our classical molecular dynamics simulations are able to describe the profound structural differences between the melt and the glassy structures of GeSe chalcogenides. These results open to the understanding of the interplay between chemical composition, atomic structure, and electrical properties in switching materials.

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File name	Size	Description
Tavanti et al. GeSe Materials Cloud.zip MD5md5:450df2cd49b089f84929a7ccf9e9a0ad	21.1 KiB	Input files for classical molecular dynamics of GeSe
README.txt MD5md5:24a6aea697ef1c91e52e34a336680d6a	682 Bytes	Explanation of the contents of the folders

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Keywords

Chalcogenides molecular dynamics amorphous Intersect