NEW STRUCTURAL MODEL FOR TRANSITION METAL-METALLOID GLASSES
NEW STRUCTURAL MODEL FOR TRANSITION METAL-METALLOID GLASSES
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DOI：
10.1038/276484a0
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发表时间：
1978-01-01
期刊：
影响因子：
64.8
通讯作者：
GASKELL, PH
中科院分区：
文献类型：
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作者：
GASKELL, PH
金属合金玻璃结构的概念性概念一般是从提出的液态和玻璃态单原子金属的纯几何球形堆积模型发展而来的。这些模型所基于的假设是，玻璃是由每种元素的球形原子随机排列组成的，即所谓的密度随机堆积（DRP）模型。由两种或两种以上化学性质不同的元素组成的玻璃状“金属”合金也可以用这种方式表示，局部原子排列是偶然产生的，只受几何因素如原子半径比的限制。这里描述的模型的构建是基于在其他类型的无定形固体中通常观察到的替代原理，即局部结构是明确定义的，并且几乎总是与在材料的结晶形式中发现的结构相同。这种“立体化学设计”的模型的属性已被计算，并被发现是在合理的协议与玻璃钯硅合金的高分辨率中子散射数据。
CONCEPTUAL notions of the structure of metallic alloy glasses have generally developed from purely geometrical sphere-packing models proposed for liquid1and glassy2,3monoatomic metals. The assumption on which these models are based is that the glass consists of a random arrangement of spherical atoms of each element—the so-called dense-random-packed (DRP) model. Glassy ‘metallic’ alloys of two or more chemically dissimilar elements can also be represented in this way, local atomic arrangements arising by chance, constrained only by geometrical factors such as the ratios of atomic radii. Construction of the model described here is based on an alternative principle commonly observed in amorphous solids of other types, namely that local structure is well-defined and almost always identical to that found in crystalline forms of the material. The properties of such a ‘stereochemically designed’ model have been computed and are found to be in reasonable agreement with high resolution neutron scattering data for glassy palladium–silicon alloys.