物理化学学报 >> 2002, Vol. 18 >> Issue (01): 39 -44 .doi: 10.3866/PKU.WHXB20020109

研究论文 上一篇    下一篇

液态Al80Fe20合金的中程有序结构

丛红日;边秀房;李辉;王丽   

  1. 山东大学材料液态结构及其遗传性教育部重点实验室,济南 250061;南京大学物理系固体微结构国家重点实验室,南京 210093
  • 收稿日期:2001-06-21 修回日期:2001-09-21 发布日期:2002-01-15
  • 通讯作者: 丛红日 E-mail:hongri_c@263.net

Mediumrange Order Structure in Liquid Al80Fe20Alloy

Cong Hong-Ri;Bian Xiu-Fang;Li Hui;Wang Li   

  1. Key Laboratory of Liquid Structure and Heredity of Materials Ministry of Education, Shandong University, Jinan 250061;State Key Laboratory of Microstructure of Solid, Nanjing University, Nanjing 210093
  • Received:2001-06-21 Revised:2001-09-21 Published:2002-01-15
  • Contact: Cong Hong-Ri E-mail:hongri_c@263.net

摘要: 利用分子动力学模拟(MD)与X射线衍射实验相结合的方法研究了Al80Fe20合金熔体的微观结构,发现在结构因子的小角部分(Q=17.5 nm-1)出现了一个明显的预峰(FSDP),且模拟值与实验值吻合得很好,这被认为是熔体中存在中程有序(MRO)的标志.通过对化学短程序参数(CSRO)α及BhatisThornton(BT)结构因子的分析计算,发现熔体中存在较强的化学序,并认为正是这种化学序导致了中程有序结构的产生. FaberZiman(FZ)偏结构因子的SFe-Fe(Q)和SAl-Fe(Q)在Q=17.5 nm-1处分别存在最大值与最小值,也是熔体中存在着超结构的表征.给出了体系的配位数及代表中程有序的原子团簇的结构模型.

关键词: Al80Fe20合金熔体, 中程有序, 分子动力学模拟, 结构因子, 预峰

Abstract: The microstructure of liquid Al80Fe20 alloy is studied by molecular dynamics simulation, combined with experiment of Xray diffraction. It is found that there exists an obvious prepeak in the small domain(Q=17.5 nm-1)of the structure factor, which is considered as indicative of the existence of mediumrange order(MRO) in the liquid. Furthermore, the results of MD simulation agree also well with those of experiment. The chemical shortrange order(CSRO) α and BhatisThornton(BT) partial structure factors show that there exists very strong CSRO in the liquid, which suggests that the CSRO result in the formation of MRO. The maximum and the minimum at Q=17.5 nm-1 in SFe-Fe(Q) and SAl-Fe(Q) of FaberZiman(FZ) partial structure factors also indicate the existence of superstructure in the liquid. We also calculate the coordination numbers of the system and give a structural model representing MRO clusters.

Key words: Al80Fe20 liquid alloy, Mediumrange order, MD simulation, Structure factor, Prepeak