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-  2018 

Ni和Y影响Al-Ni-Y金属玻璃形成能力的本征机理

DOI: 10.11951/j.issn.1005-0299.20170362

Keywords: Al基金属玻璃,玻璃形成能力,电子结构,伪布里渊区,费米面
Al-based
,metallic,glasses,glass,forming,ability,electronic,structure,pseudo-Brillouin,zone,fermi,sphere

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Abstract:

为了揭示Ni和Y元素对Al-Ni-Y三元金属玻璃的玻璃形成能力影响的本征机理,且基于费米面和伪布里渊区理论,提出了Ni和Y元素对Al-Ni-Y三元金属玻璃的玻璃形成能力的影响分为两种情况:Ni原子通过Al和Ni原子之间的电子轨道杂化效应,改变费米面直径(2KF),从而影响Al基金属玻璃的玻璃形成能力;Y原子通过整体原子的静态结构,改变伪布里渊区(KP),最终影响Al基金属玻璃的玻璃形成能力.费米面和伪布里渊区尺寸通过电子能量损失谱(EELS)、X射线衍射(XRD)和X射线光电子能谱(XPS)获得.研究表明,当两者相互作用机制满足2KF=KP条件时,费米能级处电子态密度最低,金属玻璃整体结构的稳定性达到最佳.在此基础上,提出了δ=|KP-2KF|判据用于衡量Al-Ni-Y三元金属玻璃的玻璃形成能力,该判据在实验上得到验证.
In order to reveal the effect of Ni and Y on the glass forming ability (GFA) of Al-Ni-Y ternary alloy system, two conclusions are drawn based on the Fermi sphere-Brillouin zone interaction and spectroscopy experiments: firste the effect of Ni is influenced by the electron hybridization between Al atom and Ni atom, changing the diameter of the Fermi sphere (2KF); second the effect of Y element mainly changes the diameter of the pseudo-Brillouin zone (KP). Their effects on the Fermi level and Brillouin zone size were obtained by the EELS (electron energy-loss spectra), XPS (x-ray photoelectron spectroscopy) and XRD (x-ray diffraction). Research results showed that the static structure changes of Al atoms and Y atoms influenced the diameter of the pseudo-Brillouin zone. The best GFA could be obtained when the Fermi surfaces nearly touched the quasi-Brillouin boundaries. On this basis, the δ=|KP-2KF| criterion was proposed to evaluate the GFA of Al-Ni-Y ternary alloy. This criterion was confirmed by the experimental results.

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