Nguyen Thi Thanh Ha, Nguyen Quang Bau, Pham Khac Hung

Main Article Content

Abstract

Abstract. In this paper, we numerically study the diffusion mechanism at atomic level in silica liquid via molecular dynamics simulation. The model consisting of 1998 particles and using the BKS potential has been constructed at the temperature from 2600 to 4500 K. Furthermore, we track the evolution of network units with x=4, 5 and 6 over different time. The simulation shows that the diffusivity depends strongly not only on the rate of the exchanging the coordinated oxygens, but also on the correlation effect. This effect is caused by the specific distribution of the exchanging coordinated oxygens (ECO) through the space which leads to spatially heterogeneous dynamics in the liquid. Analyzing the temperature dependence of the correlation coefficient F we found that the slowdown in dynamics near glass transition point is ascribed from percolation of the domains where high frequent exchanging coordinated oxygens occurs.

References

[1] Michael I. Ojovan, Advanc. in Cond. Matt. Phys., (2008) 817829
[2] G. Tarjus, in Dynamical Heterogeneities in Glasses, Colloids and Granular Media, edited by L. Berthier, G. Biroli, J.-P. Bouchaud, L. Cipelletti, W. van Saarloos (Oxford University Press, Oxford, 2011).
[3] Walter Kob, Sándalo Roldán-Vargas, Ludovic Berthier, Physics Procedia 34 ( 2012)
[4] P.K.Hung, N.T.T.Ha, N.V.Hong, J. of Non-Cryst. Solids 358 (2012)
[5] Michael Vogel and Sharon C. Glotzer, Phys. Rev. Lett. 92, 25, 255901 (2004)
[6] Hideyuki Mizuno and Ryoichi Yamamoto, Phys. Rev. E 84 ,011506 (2011)
[7] A. H. Marcus, J. Schofield, and S. A. Rice, Phys. Rev. E 60, 5725 (1999)
[8] Hideyuki Mizuno and Ryoichi Yamamoto, , Phys. Rev. E 84, 011506 W (2011)
[9] M. Dzugutov, S. I. Simdyankin, and F. H. M. Zetterling, Phys.Rev. Lett. 89, (2002)
[10] A. Heuer and K. Okun, J.Chem. Phys.106, 6176 (1997)
[11] Y. Gebremichael, T. B. Schrøder, F. W. Starr, and S. C. Glotzer, Phys. Rev. E 64, 051503 (2001)
[12] Michael Vogel and Sharon C. Glotzer, Phys. Rev. Lett. 92, 25, 255901 (2004)
[13] Hideyuki Mizuno and Ryoichi Yamamoto, Phys. Rev. E 82, 030501R (2010)
[14] B. Schnell, H. Meyer, C. Fond2, J.P. Wittmer, J. Baschnagel, Eur. Phys. J. E (2011)
[15] D. Rodney and T. Schrøder, Eur. Phys. J. E (2011)
[16] P.K. Hung and N.T. Nhan, Scripta Materialia 63, 12 (2010)
[17] P K Hung, N V Hong and L T Vinh, J. of Phys: Cond. Matt., 19, 466103 (2007)
[18] R. H. Doremus, J. of Appl. Phys, 92, 7619 (2002)
[19] R. H. Doremus, American Ceramic Society Bulletin, 82, 3, 59 (2003)