New Approaches to the Computer Simulation of Amorphous Alloys: A Review

Materials

Ariel A. Valladares¹  Juan A. D໚z-Celaya¹  Jonathan Galván-Colín¹  Luis M. Mej໚-Mendoza²  José A. Reyes-Retana¹  Renela M. Valladares²  Alexander Valladares²  Fernando Alvarez-Ramirez³  Dongdong Qu⁴ 

[1] Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Ciudad Universitaria, Apartado Postal 70-360, Mexico, D.F. 04510, Mexico; E-Mails:;Facultad de Ciencias, Universidad Nacional Autónoma de Mexico, Ciudad Universitaria, Apartado Postal 70-542, Mexico, D.F. 04510, Mexico; E-Mails:;Programa de Ingeniería Molecular, IMP, Eje Central Lázaro Cárdenas 152, Mexico, D.F. 07730, Mexico; E-Mail:;School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150001, China; E-Mails:

关键词: amorphous alloys;    computational simulations;    bulk metallic glasses;    electronic structure;    vibrational densities of states;   

DOI  :  10.3390/ma4040716

来源: mdpi

【 摘 要 】

In this work we review our new methods to computer generate amorphous atomic topologies of several binary alloys: SiH, SiN, CN; binary systems based on group IV elements like SiC; the GeSe₂ chalcogenide; aluminum-based systems: AlN and AlSi, and the CuZr amorphous alloy. We use an ab initio approach based on density functionals and computationally thermally-randomized periodically-continued cells with at least 108 atoms. The computational thermal process to generate the amorphous alloys is the undermelt-quench approach, or one of its variants, that consists in linearly heating the samples to just below their melting (or liquidus) temperatures, and then linearly cooling them afterwards. These processes are carried out from initial crystalline conditions using short and long time steps. We find that a step four-times the default time step is adequate for most of the simulations. Radial distribution functions (partial and total) are calculated and compared whenever possible with experimental results, and the agreement is very good. For some materials we report studies of the effect of the topological disorder on their electronic and vibrational densities of states and on their optical properties.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.