By employing quasielastic neutron scattering, we studied the atomic-scale relaxation dynamics and transport mechanism of ${\mathrm{La}}_{50}{\mathrm{Ni}}_{15}{\mathrm{Al}}_{35}$ and ${\mathrm{Ce}}_{70}{\mathrm{Cu}}_{19}{\mathrm{Al}}_{11}$ metallic glass melts in the temperature range of $>200\mathrm{K}$ above their liquidus temperatures. The results show that both liquids exhibit stretched exponential relaxation and Arrhenius-type temperature dependence of the effective diffusion coefficient. The ${\mathrm{La}}_{50}{\mathrm{Ni}}_{15}{\mathrm{Al}}_{35}$ melt exhibits an activation energy of 0.545 ± 0.008 eV and a stretching exponent ∼0.77 to 0.86 in the studied temperature range; no change of activation energy, as suggested in previous reports, associated with liquid-liquid phase transition was observed. In contrast, the ${\mathrm{Ce}}_{70}{\mathrm{Cu}}_{19}{\mathrm{Al}}_{11}$ melt exhibits larger diffusivity with a much smaller activation energy of $0.201\pm 0.003\mathrm{eV}$ and a smaller stretching exponent ∼0.51 to 0.60, suggestive of more heterogeneous dynamics.

中文翻译：

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准弹性中子散射研究金属玻璃熔体La50Ni15Al35和Ce70Cu19Al11的原子动力学

通过使用准弹性中子散射，我们研究了原子尺度弛豫动力学和传输机制 ${拉}_{50}{你}_{15}{铝}_{35}$ 和 ${铈}_{70}{铜}_{19}{铝}_{11}$ 金属玻璃在以下温度范围内熔化 $>200\mathrm{钾}$高于它们的液相线温度。结果表明，两种液体都表现出拉伸指数弛豫和有效扩散系数的阿伦尼乌斯型温度依赖性。这${拉}_{50}{你}_{15}{铝}_{35}$在所研究的温度范围内，熔体的活化能为 0.545 ± 0.008 eV，拉伸指数约为 0.77 至 0.86；没有观察到与液-液相转变相关的活化能变化，如先前报告中所建议的那样。相比之下，${铈}_{70}{铜}_{19}{铝}_{11}$ 熔体表现出更大的扩散率和更小的活化能 $0.201\pm 0.003\mathrm{电动汽车}$ 和较小的拉伸指数 ~0.51 到 0.60，表明更多的异构动力学。