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Heating rate effects in simulated liquid Al2O3

Published online by Cambridge University Press:  30 November 2005

Vo Van Hoang*
Affiliation:
Dept. of Physics, College of Natural Sciences, HochiMinh City National University, 227 Nguyen Van Cu Str., Distr. 5, HochiMinh City, Vietnam
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Abstract

The heating rate effects in simulated liquid Al2O3 have been investigated by Molecular Dynamics (MD) method. Simulations were done in the basic cube under periodic boundary conditions containing 3000 ions with Born-Mayer type pair potentials. The temperature of the system was increasing linearly in time from the zero temperature as $T(t)=T_0 +\gamma t$ , where $\gamma $ is the heating rate. The heating rate dependence of density and enthalpy of the system was found. Calculations show that static properties of the system such as the coordination number distributions and bond-angle distributions slightly depend on $\gamma $ . Structure of simulated amorphous Al2O3 model with the real density at the ambient pressure is in good agreement with Lamparter's experimental data. The heating rate dependence of dynamics of the system has been studied through the diffusion constant, mean-squared atomic displacement and comparison of partial radial distribution functions (PRDFs) for 10% most mobile and immobile particles with the corresponding mean ones. Finally, the evolution of diffusion constant of Al and O particles and structure of the system upon heating for the smallest heating rate was studied and presented. And we find that the temperature dependence of self-diffusion constant in the high temperature region shows a crossover to one which can be described well by a power law, $D\propto (T-T_c )^\gamma $ . The critical temperature T c is about 3500 K and the exponent $\gamma $ is close to 0.941 for Al and to 0.925 for O particles. The glass phase transition temperature T g for the Al2O3 system is at anywhere around 2000 K.

Keywords

Type
Research Article
Copyright
© EDP Sciences, 2006

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References

Larmagnac, J.P., Grenet, J., Michon, P., J. Non-Cryst. Solids 45, 157 (1981) CrossRef
O'Reilly, J.M., Hodge, I.M., J. Non-Cryst. Solids 131–133, 451 (1991) CrossRef
Yuren, W., Koichi, K., Appl. Phys. 90, 2247 (2001)
Avramov, I., Gutzow, I., J. Non-Cryst. Solids 104, 148 (1988) CrossRef
Nakayama, K., Kojima, K., Tamaru, I., Masaki, Y., Kitagawa, A., Suzuki, A., J. Non-Cryst. Solids 198–200, 758 (1996) CrossRef
Giovambattista, N., Stanley, H.E., Sciortino, F., Phys. Rev. E 69, 050201 (2004) CrossRef
Vo Van Hoang, , Phys. Rev. B 70, 134204 (2004) CrossRef
Vo Van Hoang, Suhk Kun Oh, Phys. Rev. E 70, 061203 (2004) CrossRef
Vo Van Hoang, , Phys. Lett. A 335, 439 (2005) CrossRef
Vo Van Hoang, Nova Science Publisher's (Inc., NewYork) (to be published as a chapter in a book)
Available at http://www.superconductivecomp.com/ Al2O3 subtrates.html
D.R. Lide, H.P.R. Frederikse, CRC Handbook of Chemistry and Physics, 76th edn. (CRC Press Inc., 1995)
Lamparter, P., Kniep, R., Physica B 234–236, 405 (1997) CrossRef
Gutiérrez, G., Johansson, B., Phys. Rev. B 65, 104202 (2002) CrossRef
Landron, C., Soper, A.K., Jenkins, T.E., Greaves, G.N., Hennet, L., Countures, J.P., J. Non-Cryst. Solids 293–295, 453 (2001) CrossRef
Landron, C., Hennet, L., Jenkins, T.E., Greaves, G.N., Coutures, J.P., Soper, A.K., Phys. Rev. Lett. 86, 4839 (2001) CrossRef
It must be accounted for 5% particles detected from a tail of more mobile ones in the atomic displacement distribution. However, all results presented in the text are qualitatively the same if the 5% are replaced by 10%, but 10% include enough particles to obtain good statistics when examining their spatial correlation
Kerrache, A., Teboul, V., Guichaoua, D., Monteil, A., J. Non-Cryst. Solids 322, 41 (2003) CrossRef
It is essential to notice that strong dynamical heterogeneities have been also found in liquids SiO2 even at the temperature of 3500 K, which is must higher than the melting point of 1983 K for the system (see in Ref. [18])
Winkler, A., Horbach, J., Kob, W., Binder, K., J. Chem. Phys. 120, 384 (2004) CrossRef
Horbach, J., Kob, W., Phys. Rev. B 60, 3169 (1999) CrossRef
Mikkelsen, J.C., J. Appl. Phys. Lett. 45, 1187 (1984) CrossRef
Brebec, G., Seguin, R., Sella, C., Bevenot, J., Martin, J.C., Acta Metall. 28, 327 (1980) CrossRef
Hess, K.U., Dingwell, D.B., Rossler, E., Chem. Geol. 128, 155 (1996)
Vo Van Hoang, Suhk Kun Oh, Phys. B 352, 342 (2004) CrossRef
W. Gotze, in Liquids, Freezing and the Glass Transition, Proceedings of the Les Houches Summer School of Theoretical Physics, Session LI, 1989, edited by J.P. Hansen, D. Levesque, J. Zinn-Justin (North-Holland, Amsterdam, 1991)