Decoupling of component diffusion in a glass-forming Zr(46.75)Ti(8.25)Cu(7.5)Ni(10)Be(27.5) melt far above the liquidus temperature.
Decoupling of component diffusion in a glass-forming Zr(46.75)Ti(8.25)Cu(7.5)Ni(10)Be(27.5) melt far above the liquidus temperature.
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DOI：
10.1103/physrevlett.113.165901
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发表时间：
2014-10
影响因子：
8.6
通讯作者：
Sri Wahyuni Basuki;A. Bartsch;Fan Yang;K. Rätzke;A. Meyer;F. Faupel
中科院分区：
文献类型：
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作者：
Sri Wahyuni Basuki;A. Bartsch;Fan Yang;K. Rätzke;A. Meyer;F. Faupel
我们报道了在远高于液相线温度T（1）的Zr（46.75）Ti（8.25）Cu（7.5）Ni（10）Be（27.5）熔体（Vitreloy 4）形成的块状金属玻璃的平衡液态中（95）Zr和（57）Co放射性示踪剂扩散系数和粘度数据，这通过准弹性中子散射得到证明。Zr扩散在T（1）处与较小组分的扩散强烈解耦超过4倍，尽管它服从斯托克斯-爱因斯坦方程。结果表明，在本Zr基金属玻璃形成系统中，扩散和粘性流动开始发展为固态，即，能量横向控制，其特征在于已经在高于模式耦合温度T（c）300 K的稳定液态中。
We report (95)Zr and (57)Co radiotracer diffusivities and viscosity data in the equilibrium liquid state of a bulk metallic glass forming Zr(46.75)Ti(8.25)Cu(7.5)Ni(10)Be(27.5) melt (Vitreloy 4) far above the liquidus temperature T(l) that are not affected by convection, as evidenced via quasielastic neutron scattering. Zr diffusion is strongly decoupled from diffusion of the smaller components by more than a factor of 4 at T(l), although it obeys the Stokes-Einstein equation. The results suggest that, in the present Zr-based metallic glass forming systems, diffusion and viscous flow start to develop solidlike, i.e., energy-landscape-controlled, features already in the stable liquid state more than 300 K above the mode coupling temperature T(c).