Modelling the atomic arrangement of amorphous 2D silica: a network analysis

Projesh Kumar Roy, Markus Heyde, Andreas Heuer
  • Physical Chemistry Chemical Physics, January 2018, Royal Society of Chemistry
  • DOI: 10.1039/c8cp01313f

Simulating the random networks in 2D silica

What is it about?

2D-silica is a recent addition to the family of 2D-materials and Silica allotropes. Near the glass transition, it shows an interesting and seemingly random pattern of silica rings of various sizes spread throughout the system. To study if there is any order in this apparent disordered pattern, computer simulation with a proper model system is quite useful. We have prepared such a 2D model for 2D-Silica. The model is based on a Yukawa type force-field which describes the interactions between the particles. It is simulated at various temperatures. At a certain temperature, we are able to match the ring-patterns of the model with the actual system with good accuracy. This helped us to establish the force-field as a valid representation of 2D-Silica system and opens up lots of opportunities for future work.

Why is it important?

The model system is quite successful to reproduce various topological properties of 2D-Silica on 2D surface. We can comment on the low-temperature behavior of the 2D-Silica, which is not attainable from experiments. This may help one to understand more on the physics of glassy systems, where bulk-silica is a prime study material. The properties of random ring-networks can be studied in much detail with this model system. We are currently preparing another paper about the thermodynamics of the ring systems in 2D-Silica based on this model, which may help to understand what kind of order is present in the ring network. Another direction to explore is the dynamics of 2D-Silica, especially the mechanistic aspects near glass transition. Work is currently undergoing in this area.

Perspectives

Projesh Kumar Roy (Author)
Westfalische Wilhelms-Universitat Munster

The modeling part of the simulation was itself very challenging, as we are effectively decomposing a 3D system into a 2D plane. However, with great help from Dr. Heyde and his group in Berlin, we were able to establish the model system in 2D. This project was a wonderful opportunity to explore the world of random networks. It was quite fascinating to discover how a seemingly random system can be generalized based on a few parameters. We are also excited about the glassy nature of the model which may help one to understand how theories of glass are related to the theories of random networks. The areas of glasses and random networks are continuously developing and we hope new insights will certainly come from someone interested out there.

The following have contributed to this page: Projesh Kumar Roy