Ti75Ni25化的短距离顺序和原子动态
Johanna Wilden1, Dirk Holland-Moritz1, Fan Yang2
1Institute for Frontier Materials on Earth and in Space, Deutsches Zentrum fur Luft- und Raumfahrt DLR, Linder Höhe, Cologne, NRW, 51147, Germany.
概括
与其他合金相比,液态- (Ti75Ni25) 呈现出更快的原子动态,这是由于化学短程顺序较少明显的原因. 这种结构差异解释了在原子移动性和扩散方面观察到的差异.
科学领域:
- 材料科学 材料科学 材料科学
- 凝聚物质物理学 凝聚物质物理学
- 物理化学 物理化学
背景情况:
- 液体合金中的原子动力学受其结构的影响.
- Ti75Ni25的化物显示出比Zr64Ni36和Ni66.7B33.3的化物更快的原子动力学.
研究的目的:
- 为了研究Ti75Ni25化的短距离结构.
- 为Ti75Ni25融物中更快的原子动态建立结构性解释.
主要方法:
- 在高纯度条件下使用静电悬浮进行无容器加工.
- 通过中子衍射 (与同位素替代) 和同步射X射线衍射来确定部分结构因子.
- 使用模式合理论 (MCT) 分析结构-动力学关系.
主要成果:
- Ti75Ni25化物表现出化学短程顺序,具有首选的Ti-Ni最近邻居.
- 这种化学短程顺序不如Zr64Ni36和Ni66.7B33.3溶中那么明显.
- 的自我扩散速度略快于的自我扩散 (DNi/DTi ≈1.2).
- 来自MCT的Onsager系数与达肯方程一致,表明在相互传播中微不足道的交叉相关性效应.
结论:
- 在Ti75Ni25中较少明显的化学短程顺序有助于其更快的原子动态.
- 液体Ti75Ni25中的结构动力学关系被模式合理论描述得很好.
- 对于在液体Ti75Ni25.25中的相互扩散而言,交叉相关性效应是最小的.
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