Tampere University of Technology

TUTCRIS Research Portal

Crystallization processes in the phase change material Ge2 Sb2 Te5: Unbiased density functional/molecular dynamics simulations

Research output: Contribution to journalArticleScientificpeer-review

Details

Original languageEnglish
Article number134105
JournalPhysical Review B
Volume94
Issue number13
DOIs
Publication statusPublished - 17 Oct 2016
Publication typeA1 Journal article-refereed

Abstract

Three extensive density functional/molecular dynamics simulations of the crystallization of amorphous Ge2Sb2Te5 (460 atoms) [Phys. Rev. B 90, 184109 (2014)PRBMDO1098-012110.1103/PhysRevB.90.184109] have been completed with simulation times of up to 8.2 ns. Together with the results of earlier simulations with and without a crystallite seed, the results clarify essential features of a complicated process. They emphasize, in particular, the stochastic nature of crystallization, the effect of bond orientations and percolation, and the importance of extended simulations of sufficiently large samples. This is particularly evident in describing the role of crystallites that can merge to form larger units or hinder complete crystallization by the formation of grain boundaries. The total pair distribution functions for the final structures are compared with available neutron and x-ray diffraction data.

Publication forum classification

Field of science, Statistics Finland