Influence of Ag substitution on the local structure and glass-forming ability of Al86Ni(8-x)Y6Agx (X=0,1,2) liquids
Influence of Ag substitution on the local structure and glass-forming ability of Al86Ni(8-x)Y6Agx (X=0,1,2) liquids
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Ag取代对Al86Ni(8-x)Y6Agx (X=0,1,2)液体局部结构和玻璃形成能力的影响
DOI：
10.1080/00319104.2015.1084880
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发表时间：
2015
影响因子：
1.2
通讯作者：
Schumacher Gerhard
中科院分区：
文献类型：
--
作者：
Liu Yao;Wang Jin;Qin Jingyu;Schumacher Gerhard
用从头算分子动力学方法研究了Al 86 Ni（8-x）Y 6Agx（X= 0，1，2）合金熔融态和玻璃态的局域结构。结果表明，Al_（86）Ni（8-x）Y_6Ag_x合金可以看作是以Ni和Y为中心的Al团簇与Ag作为“胶原子”的组合。在Al_（86）Ni_（77）Y_（6Ag）_1合金中，几乎没有发现第一、第二配位，但观察到一个介于7.5 ~ 9 μ m之间的中程有序。与Al 86 Ni 8 Y 6合金相比，该合金的非晶形成能力和热稳定性的提高归因于Ag-Ag关联的中程有序。在Al 86 Ni 6 Y 6Ag 2中发生了第二次Ag-Ag配位，导致非晶形成能力下降。冷却过程中，所有构成元素之间的原子间距离都会增加。这种增加归因于Al原子周围的团簇分布向Al周围具有更高配位数的团簇变化。
The local structure of Al86Ni(8-x)Y6Agx(X= 0,1,2) molten and glassy alloy was investigated byabinitiomolecular dynamics simulation. It transpired that the Al86Ni(8-x)Y6Agxalloy can be considered as a combination of Ni- and Y-centred Al clusters with Ag as ‘glue atoms’. First and second Ag–Ag coordination was scarcely found in Al86Ni7Y6Ag1, but a medium-range order between 7.5 and 9 Å was observed. The enhanced glass-forming ability and thermal stability of the alloy compared with Al86Ni8Y6can be attributed to the medium-range order of the Ag–Ag correlation. A second Ag–Ag coordination occurs in Al86Ni6Y6Ag2and results in a decrease in glass-forming ability. The inter-atomic distances between all constituting elements increase during cooling. This increase is ascribed to a change in distribution of clusters around Al atoms towards clusters with higher coordination number around Al.