Thermal hysteresis of a simulated Al₂O₃ system

作     者：Hoang, VV 

作者机构：HochiMinh City Natl Univ Coll Nat Sci Dept Phys Ho Chi Minh City Vietnam 

出 版 物：《EUROPEAN PHYSICAL JOURNAL B》 (Eur. Phys. J. B)

年 卷 期：2005年第48卷第4期

页      面：495-500页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

主　　题：Glasses Amorphous materials, glasses and other disordered solids Structural modeling: serial-addition models, computer simulation 

摘      要：Thermal hysteresis in a simulated Al2O3 system has been investigated using a 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 system was cooled down from 7000 K to 0 K and heated up from 0 K to 7000 K by the same cooling/heating rate of 1.7178 x 10(14) K/s. The temperature dependence of the system density upon cooling and heating shows thermal hysteresis. The differences between structure and dynamics of the models obtained by cooling (MOBC) and heating (MOBH) at three different temperatures of 2100 K, 3500 K and 5600 K have been detected. Calculations show that the differences in the dynamics of the systems are more pronounced than those in the structure. Furthermore, dynamical heterogeneities in MOBC and MOBH at the temperature of 2100 K have been studied through a non-Gaussian parameter and comparison of partial radial distribution functions (PRDFs) for the 10% most mobile or immobile particles with their corresponding mean ones. Cluster size distributions of the 10% most mobile or immobile particles in MOBC and MOBH at the temperature of 2100 K have been obtained. Calculations show that differences in dynamical heterogeneities are pronounced.