Asymmetric crystallization during cooling and heating in model glass-forming systems

Abstract

We perform molecular dynamics (MD) simulations of the crystallization process in binary Lennard-Jones systems during heating and cooling to investigate atomic-scale crystallization kinetics in glass-forming materials. For the cooling protocol, we prepared equilibrated liquids above the liquidus temperature $T_l$ and cooled each sample to zero temperature at rate $R_c$. For the heating protocol, we first cooled equilibrated liquids to zero temperature at rate $R_p$ and then heated the samples to temperature $T>T_l$ at rate $R_h$. We measured the critical heating and cooling rates $R_h^{\ast }$ and $R_c^{\ast }$, below which the systems begin to form a substantial fraction of crystalline clusters during the heating and cooling protocols. We show that $R_h^{\ast }>R_c^{\ast }$, and that the asymmetry ratio $R_h^{\ast }/R_c^{\ast }$ includes an intrinsic contribution that increases with the glass-forming ability (GFA) of the system and a preparation-rate dependent contribution that increases strongly as $R_p\to R_c^{\ast }$ from above. We also show that the predictions from classical nucleation theory (CNT) can qualitatively describe the dependence of the asymmetry ratio on the GFA and preparation rate $R_p$ from the MD simulations and results for the asymmetry ratio measured in Zr- and Au-based bulk metallic glasses (BMG). This work emphasizes the need for and benefits of an improved understanding of crystallization processes in BMGs and other glass-forming systems.

arXiv comment8 pages, 7 figures

References in corpus (8)

• Shortcomings of the Bond Orientational Order Parameters for the Analysis of Disordered Particulate Matter
• Precursor-mediated crystallization process in suspensions of hard spheres
• Crystal nucleation of hard spheres using molecular dynamics, umbrella sampling and forward flux sampling: A comparison of simulation techniques
• Computer Simulations of Supercooled Liquids and Glasses
• Molecular Dynamics Study of Long-Lived Structures in a Fragile Glass Forming Liquid
• Avalanches mediate crystallization in a hard-sphere glass
• Computational studies of the glass-forming ability of model bulk metallic glasses
• Glass Formation and Crystallization of a Simple Monatomic Liquid

Cited by in corpus (1)

• Spectral descriptors for bulk metallic glasses based on the thermodynamics of competing crystalline phases