Glass-liquid transition in a less-stable metallic glass
Glass-liquid transition in a less-stable metallic glass
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DOI：
10.1103/physrevb.72.052201
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发表时间：
2005-08-01
影响因子：
3.7
通讯作者：
Tarumi, R
中科院分区：
文献类型：
--
作者：
Ichitsubo, T;Matsubara, E;Tarumi, R
一种稳定的金属玻璃，SMG，通常被视为一种非晶合金，表现出可逆的玻璃-液体转变。在这里，我们通过实验证明，即使在不太稳定的金属玻璃中，LMG，仅通过快速熔体淬火制备，并且在普通加热速率下迅速结晶而没有玻璃化转变，足够快的加热通过抑制结晶暴露出玻璃->液体转变。SMG的Pd42.5Ni7.5Cu30P20和LMG的Zr70Ni30的实验玻璃化转变温度T-g和结晶温度T-x绘制为加热速率β的函数。两条外推曲线，T-g-log β和T-x-log β，相交于一个相当小的β，例如，类似于10（-4）摄氏度/分钟，对于SMG，而它们相交于一个大的β，例如，类似于10摄氏度/分钟，对于LMG。如此大的β与传统的加热速率相当，使得很难观察到LMG中的可逆玻璃化转变，并且反映了玻璃态的低热稳定性。
A stable metallic glass, SMG, is often viewed as an amorphous alloy exhibiting a reversible glass liquid transition. Here we show experimentally that even in a less-stable metallic glass, LMG, which is prepared only by rapid melt quenching and promptly crystallized without glass transition at the ordinary heating rate, sufficiently rapid heating exposes the glass -> liquid transition by suppressing crystallization. The experimental glass transition T-g and crystallization T-x temperatures were plotted as a function of heating rate beta, for Pd42.5Ni7.5Cu30P20 of SMG and for Zr70Ni30 of LMG. Two extrapolated curves, T-g-log beta and T-x-log beta, intersect at a quite small beta, e.g., similar to 10(-4) degrees C/min, for SMG, whereas their intersection occurs at a large beta, e.g., similar to 10 degrees C/min, for LMG. Such a large beta that is comparable to conventional heating rates makes it difficult to observe the reversible glass transition in LMG, and reflects low thermal stability of the glassy state.