Local atomic arrangements and their topology in Ni–Zr and Cu–Zr glassy and crystalline alloys
Local atomic arrangements and their topology in Ni–Zr and Cu–Zr glassy and crystalline alloys
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DOI：
10.1016/j.actamat.2013.01.027
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发表时间：
2013-04
期刊：
影响因子：
9.4
通讯作者：
I. Kaban;P. Jóvári;V. Kokotin;O. Shuleshova;B. Beuneu;K. Saksl;N. Mattern;J. Eckert;A. Greer
中科院分区：
文献类型：
--
作者：
I. Kaban;P. Jóvári;V. Kokotin;O. Shuleshova;B. Beuneu;K. Saksl;N. Mattern;J. Eckert;A. Greer
采用不同的实验技术（X射线衍射、同位素替代中子衍射、扩展X射线吸收光谱）和理论方法（反向蒙特-卡罗模拟、分子动力学模拟、Voronoi分析）来阐明Ni-Zr和Cu-Zr合金在玻璃态和晶态下的原子结构，并解释Ni 64 Zr 36和Cu 65 Zr 35组成的玻璃形成能力的差异。这两种玻璃显示出类似的强拓扑有序，但它是建立在Ni 64 Zr 36玻璃比Cu 65 Zr 35玻璃中的化学有序的程度要明显得多。短程原子的顺序和拓扑结构的玻璃和晶体结构是显着不同的，这些差异被认为是阻碍晶体的成核和生长，从而促进快速冷却后的Ni 64 Zr 36和Cu 65 Zr 35液态合金的玻璃形成。Cu 65 Zr 35合金在玻璃态和晶态的较大差异，建议发挥决定性的作用，在提高其块体玻璃形成能力。
Different experimental techniques (X-ray diffraction, neutron diffraction with isotopic substitution, extended X-ray absorption spectroscopy) and theoretical methods (reverse Monte-Carlo simulation, molecular dynamics modelling, Voronoi analysis) were applied to elucidate the atomic structure of Ni–Zr and Cu–Zr alloys in glassy and crystalline states and to explain differences in the glass-forming abilities of the Ni64Zr36and Cu65Zr35compositions. Both glasses show similar strong topological ordering, but it is established that the degree of chemical ordering is much more pronounced in Ni64Zr36glass than in Cu65Zr35glass. The short-range atomic order and topology in the glassy and crystalline structures are remarkably different, and these differences are presumed to hinder crystal nucleation and growth, hence promoting glass formation upon fast cooling of the Ni64Zr36and Cu65Zr35liquid alloys. The larger differences observed for the Cu65Zr35alloy in glassy and crystalline states are suggested to play a decisive role in increasing its bulk-glass-forming ability.