Regensburg 2016 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 51: Glasses (joint session CPP/DY, organized by DY)
CPP 51.2: Vortrag
Donnerstag, 10. März 2016, 10:00–10:15, H48
Theoretical investigation of mechanism and statistical properties of a model two-dimension silica glass. — •Projesh Kumar Roy1 and Andreas Heuer2 — 1Graduate school of chemistry, Institute of physical chemistry , Correnstrasse 28/30, D-48149, Muenster — 2Institute of physical chemistry , Correnstrasse 28/30, D-48149, Muenster
The discovery of 2D silica glass [1] [2] has offered a realistic description of random network theory of silica glass structure; debated for over 80 years[3]. This extremely thin material consists of two layers of silica and exhibits 2D properties in all phases. In the glass phase, the silica network shows a log-normal ring distribution with a typical micro-structure or triplet distribution. For simulations two different models based on a Soft - core Yukawa potential[4] and a Stillinger Weber type multi-body potential, have been employed with a binary mixture of silicon and oxygen type particles. After energy minimization, the defect free structures were identified and their ring statistics were compared with the experiment. Going beyond the experiment, the observations can be related to the underlying local energies. Furthermore, two major mechanisms turn out to be responsible for creating various random networks. On this basis a new Monte-Carlo algorithm is proposed for generating random networks of defect free 2D silica.
[1] Heyde M., Shaikhutdinov S., Freund H.-J., Chem. Phys. Lett. 550, 1 (2012). [2] Huang P. Y. et al, Nano Lett. 12, 1081 (2012). [3] Zachariasen W.H., J. Am. Chem. Soc. 54, 3841 (1932). [4] Mendez-Maldonado G.A., et al., J. Chem. Phys. 137, 054711 (2012).